92 Toyota Pickup surging idle issue

Quite a few things will cause a surging idle, improper fuel mixture, vacuum leaks (check all vacuum lines) fouled spark plugs, dirty mass airflow sensor/meter, dirty throttle body, etc.

Also, you may want a shop to check your ignition system for proper functioning, sometimes pickup coils in or around the distributor get hot and malfunction.

Thanks...what seems especially weird to me is that I just realized that this happens only when the brake is applied,. If I let off the brake the idle returns to "normal", although it seems a bit high?

You may have stumbled upon the answer yourself, remember when applying power brakes, engine vacuum is used to help the brake booster, that really large circular thing behind the master cylinder for the brakes, so it is possible that the brake booster is bad, it happens with high mileage vehicles, check with a brake shop, usually they offer free inspections.

believe it or not, even though this is a 1992, it has less than 60,000miles on it, and I am the only owner. internet searches tell me that this can also be caused by vacuum line leaks, but this is definitely something related to brakes! I've turned the idle down as low as possible ( via idle screw) when the engine is warm, but it still seems to be running high. I had front brake pads replaced last month, but they say the idle was fine. I don't think they did much road time with it though because they claim they couldn't duplicate the idle loping. they also tell me they "cleaned" the idle/air control valve. this truck runs sooo good when the engine is cool, but once it warms... then the issue comes into play. very frustrating. any ideas on how I can test the brake booster myself? the guys who put the pads on probably didn't check this, but they did say the rotors looked ok, and like I said, it really doesn't have that many miles on it. I appreciate the feedback.

ps- I will try the things previously mentioned. just throwing things out there to get as much info as possible so whenever I have a chance to focus on it, I will be prepared. most of this stuff is new to me, but I am learning for future reference. like I said, she runs great when cool, and only happens when warm and with brakes engaged. at least that info will isolate it a bit, right? as far as vacuum lines, are they all created equal? does touching the brakes bring them all into play?

Push brake pedal 4 times with engine off, make sure there is no change in pedal reserve distance, depress pedal again, start engine, if pedal goes down slightly its ok. Then, start engine for 2 minutes, push brake pedal 4 times slowly, if pedal goes down farther the first time but rises after the 2nd or 3rd time it is air tight. Lastly, push brake pedal while engine running, then stop engine with pedal still depressed for 30 seconds, if there is no change in pedal reserve travel, the booster is all well, and air tight. Of course check the large vacuum line to booster, all vacuum lines should be tight on their connections, sometimes you can cut off a small section and reattach if there is enough hose. Hope this works.

thanks! will do!

If you find that your brake booster and vac lines are good, try cleaning or replacing your IAC valve yourself. The shops idea of "Cleaning" could be just spraying some carb clean into your throttle body. Sometimes that will do the trick, but if it is severely built up with carbon, you will actually have to tear it down. Here is a video on how to properly clean it: https://www.youtube.com/watch?v=RgpIg-WkwOY

thanks very much! I'll keep that in mind. haven't had time to get into it much and still driving it the way it is. when it starts surging, I take my foot off the brake, and it stops. so, now that I know that, I can control it a bit better. I have to get it resolved soon, though.

hmmm, after watching the video, I am hoping this isn't something I have to do. I really think this seems like more of a vacuum situation, but if all else fails, I will have a friend help with this iac valve cleaning. the repair guys said they cleaned it, and mentioned that it had been taken off before (not sure when that was though because I am the only owner, so?) so I imagine they looked inside? unfortunately, repair guys are like doctors. sometimes they are great, sometimes they aren't. I will have to call and see if they remember what they did and didn't do.

With any luck it's just a simple vacuum leak like skipatrol suggested....post back and let us know what you find....

I will, and I definitely appreciate all the help!

tried brake booster test. all seems fine. what a pain in the butt this is. in fact, it seems to be getting worse. if I take my foot off the brake, it stops surging, but still idles at what seems to be above normal. it starts out fine, until it warms up. I wish there was a way to test for vacuum leaks that an "auto deficient" person like myself could do.

Willwoff, did some research and this is what one guy said who was having your exact problem: The reason it will surge is because you are letting un-metered air into the intake and when you apply the brakes it requires vacuum for the booster, adds more fuel then realizes this is too much fuel, cuts injectors then levels out again... It took me ALONG time to figure this one out. dont believe me? take your IAC off and seal the TB up with a block off plate in place of the IAC. Bet it wont surge anymore! They are activated by coolant temp to open and close for quicker warm up. When they stick then you get this surging up to 1400 RPM or so then a rapid drop in RPM's and the cycle continues as long as you are on the brake pedal! In other words it's the IAC that's bad.

Reelin68...you answered a question I was just getting ready to post. I sort of understood the part about the brake booster effect (although yours was more precise and accurate), but I am also wondering about why would it happen only when warm as opposed to when the engine was cold? does that involve the IAC as well? is it sticking and once it warms up it causes the problem? seems weird that it would do it only when the engine is warm. Since this only happens when warm and when brake is applied, are you saying to take the IAC valve off when engine is warm, then block throttle body? will it crank with the IAC off? I appreciate the explanations. I'm one of those people who likes to know why because it helps me understand the situation and I feel I can think it out better. does this also effect overall idle? my truck idles too high when warm, even when not surging, but not when cool. this is going to take me a long time, but I am going to make a checklist and try going down the list from vacuum lines, etc. thanks...

Willwoff, the explanation I found wasn't from my personal experience. I found it on a Toyota forum. I think what the guy was saying is that as the truck gets warmer, the IAC opens and closes to meter in more air as needed. What he is saying is the metering device within the IAC is stuck open. This is allowing too much air into the throttle body causing the extreme high idle. If you re-watch the video I sent you earlier, you will see the part that gets stuck open or closed due to carbon build up. As for removing the IAC and covering the hole, I think that would restrict the amount of air into the system, which would eliminate the surge upon warm up.

by the way...I can't even find the IACV either looking under the hood, or in my manual. this is a 92 Toyota pickup 22re. any hints?

This is what you are looking for.....

I've been reading forums for almost a month, and everyone has a different suggestion, and answer, and they all swear it is the answer. it is appreciated, but I suppose I will just have to find someone I can trust and TRY and make some sort of checklist for them. I cant even locate the damn thing (iacv). thanks for the input. if I ever find out the problem, I will post my own solution. until then....

http://www.yotatech.com/f116/22re-i-c-valve-where-whats-look-like- 143319/

Hope the above link helps. If you ever do get to the bottom of it all, post back with the solution. Will be interesting to know.....thanks!

that link isn't working

sorry, I found the page..thanks:)

Ok, I spent most of today trying to come up with something regarding this loping idle. After getting the engine warm and having the loping start when touching the brake, I tried to look and see if I could find a leak while the engine was running. I saw that the rubber hose covering to my PCV valve was loose and made sure that was tight, but it still loped. Then, I checked the front PCV hose (the one that runs from the valve cover to the throttle body) and when I removed one end of it, the engine idle dropped and went back to normal! So, I got in the truck, depressed the brake, and no lope! After that, I drove a few blocks with the hose disconnected, and still NO LOPE! Weird, huh? I then noticed a small crack at the very base of that hose, so I will change it out tomorrow and see if that is the issue, because I obviously can't just leave it off. But, it seems to me that this port actually is an emission port and the hose flows air into the throttle bottle right beside the throttle position sensor. (In the photo, I've disconnected the TPS so ignore that.) I've no idea why a leak in the hose would cause a lope, yet having the hose completely removed would resolve it. Any ideas on this? Could this be an accidental way of checking my IACV? (I still can't find it, and I took the truck to the mechanic who I thought had told me he cleaned it...and he couldn't find it either. ok....) I'll include a photo and would love to hear feedback!

Nice discovery! I thought you may have a plugged PCV but I don't see one. It looks like it just sucks the vapors straight out of the top. Check out this video. Same engine as you, and same problem. Very easy fix. https://www.youtube.com/watch?v=czOG-4XdxOQ

nope. this was already done before I hit this forum. the valve was clean. the pcv valve is in the back. you cant see it in this pic.

It may really be of help to you to get a Haynes Service manual (napa auto parts) and a hand vacuum pump. With this tool, checking hoses for leaks is very easy. The valve probably cleaned may have been the EGR vacuum modulator valve, a common cause of problems in Toyotas, they get carbon fouled. EGR valves go bad as well, and do not function until engine is warm. With a vacuum pump, you can connect to EGR hose, and when vacuum is applied, engine should run rough or die, even when cold. If you are experiencing poor fuel economy poor acceleration, or hesitates under acceleration, the EGR valve may not be shutting off. Either way, you really need to check all vacuum lines, as you found even the slightest crack can make a difference. Hope this helps. Between all of us we WILL figure this out. LOL.

I forgot, The EGR valve, and EGR vacuum modulator on YOUR engine are located just out of your picture to the rear of the valve cover on the right side.

skipatrol... I could swear the mechanic told me he had cleaned the iacv, and even mentioned someone had "been in there before", but when I went to the shop yesterday and asked him if he just cleaned it or took it apart, he looked confused. when I asked him where it was (iacv), he had no clue, and couldn't locate it in the engine. he then said he cleaned the throttle body, not the iacv! Big difference, but maybe it was my error. I just got a Haynes repair manual recently, so that's a good thing. Is this vacuum pump what you are speaking of in this link? http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html Also, what is your thought regarding the fact that the problem goes away when I remove the front pcv tubing as in the pic? Thanks...

that vacuum pump is exactly the one I have, and will help you tremendously. As for your engine the reason no one can find the iacv is that your engine has none, look in your manual under emission controls for 89-later EFI engines to help you out. I'll check out the pic soon.

If I do a parts search for 92 Toyota pickup, they list an IACV, but the manual doesn't mention it. This is getting very muddy. I probably need to take this to someone who can put it on a diagnostic machine.

ok...this situation just got worse. over the past few days I have noticed the brake pedal going to the floor on occasion, but mostly all was well, but still loping like hell when I idled and pressed on the brake. but, now...after testing and retesting the booster, which seemed to pass one part of the test, but fail others, my brakes go ALL the way to the floor. basically, my truck is now undrivable. when I first pump the brake it is tight, but as soon as I turn on the engine...it goes all the way to the floor. it will stop the car, but just barely and I even felt like the rear locked up on my last drive around the block. I spoke to a mechanic who says I may have a bad master cylinder AND a brake booster. any thoughts, anyone? I will have to either have it towed or take a risky drive to the shop, which isn't open until Tuesday. btw, my fluid level is fine, and I notice no leak. could air have gotten in somewhere?

never mind....I will post my results if I ever get the idle issue resolved, but the brake issue obviously comes first. I kind of doubt if the booster is the issue, although I almost wish it was so I could solve two issues with one answer, but brake boosters are supposed to ASSIST the brake pedal. if a booster was this bad, wouldn't it be harder to push the pedal? just wondering out loud. like I said, I will post the answer for others once I find it. thanks for the previous efforts.

Try bleeding the brakes to get rid of air. A little air is ok, but a lot is not ok. If the brake fluid is blackened before bleeding, then the master cylinder is suspect, bits of rubber from the cylinder may be deteriorating, causing the black fluid. Repeat whole brake test again after bleeding.

I had the truck towed to a repair shop. It definitely felt like air in the system, but the fluid level was high. Maybe a bit dark though. Won't really even stop anymore. Anyway, I will post back and see if they can resolve all the issues. Been a good truck since I bought her new in '92 and with still under 60k original miles, so she may need a bit of care.

Update...master cylinder went bad. I guess it has been coming on for a while because I've noticed the brake going to the floor now and then, but it totally went finally. Good news is that it has been replaced and brakes are back. Bad news is that idle issue is still there.

Ok, so I discovered that if I disconnect the emission hose going to the throttle bottle as I posted earlier with the photo OR disconnect the throttle position sensor, the issue goes away. So, I tried to test the TPS this morning with a multimeter. I couldn't get ANY reading from any of the 3 prongs on the meter. When I tested the connector directly (when it was unconnected), I got a reading of 5. I am not expert in any of this, but I think I used the meter correctly. So, I will explore this further.

ps- the above tests were done with the key on, but the engine not running.

Check for any new codes before proceeding so you don't have to do a wild goose chase. I'll check back later.

You will need to buy a thickness guage before testing TPS with an ohm meter.

Don't forget to test the EGR valve and vacuum modulator, see my above posts. then let us know what you found out.

first, I have no way to check for codes. second, why do I need a thickness gage to check to the TPS with an ohms meter? Third, I haven't gotten a vacuum pump yet, so I will deal with that once I find out if the TPS is good.

Stumbled onto this because my truck is having the same problems. Same surging idle issue. Haven't started really checking any thing this forum has said yet. Figured I would see if the guy who started this got his issue resolved. I just installed a new 22re into my 1993 truck. Got it all back together and have about 150 miles on the brand new engine. I noticed the surging idle about two weeks into driving it. Pretty much same issue as the other guy. Stumbled around and realized the breaks are related to the problem. Let me know if you can help out.

hi..i'm the guy in the post and no...I haven't gotten the issue resolved. my master cylinder went bad in the middle of all this mess, so that threw me for a loop as well. that is resolved, but the idle is just as bad as ever. so far I have lowered the idle as low as i can thru the idle screw nearest the throttle cable, changed the pcv valve, checked the brake booster (fine), cleaned the valve which carries coolant and is located right behind the thermostat (not sure what it is called, but there is a youtube video swearing this solves the issue...it didn't.). I can't find a vacuum leak anywhere and even removed the idle screw to check the rubber gasket to see if there was a leak. the ONLY thing I have discovered is that if the engine is warm and the idle is surging, it actually stops if I remove the connector to the throttle position sensor or the emission hose coming from the crankcase going into the throttle body. so...it seems it is something in that area. the throttle position sensor is good, I believe because it is getting voltage, and it shows resistance on an ohm meter. it is beyond my current ability, and/or stress level, to remove the throttle body to clean the idle/air valve (auxillary air valve), but I believe this may be what needs to be done. since it is all I have to drive, I will have to wait until someone ( a friend) who is more capable helps me. BEFORE I DO THIS THOUGH....I also want my friend to be able to check the rpm since I have no tach, and see if the other idle needs to be adjusted as opposed to just the large screw on the top left near the throttle body. this problem came about, I believe, a long while ago after someone re-adjusted the idle and it may be just idled too high. my truck only has 59,000m on it, and nothing I have checked so far seems dirty, although my cooland has had crud in it and that may have blocked, or clogged something. this issue has been a pain in the butt and continues to be. hope something I've said helps you resolve your issue. keep me posted.

Try replacing your radiator temp sensor. If bad, those will also cause idle issues.

you mean my thermostat? already done, but I cant understand why that would do it. some of this stuff seems a bit "out there". I'm looking for someone who actually has had a similar situation..with a Toyota 22re engine... and has resolved it, please.

No, not the thermostat. The radiator temp sensor or coolant temp sensor. Just google 1992 Toyota pickup radiator temp sensor. A pic should pop up.

I solved my problem I believe this afternoon. I watched the youtube video. It says it is a 22r but in the video it is actually a 22re just like ours. https://m.youtube.com/watch? v=Y0Gfm2Dy7E4 Seemed simple so I tried it. There was some noticable dirt in the threads which proved it was sucking in air. Put reckon tape over the idle screw. About 4 taps and screwed it on 12 rotaions to where it was before I took it off. Made a tight seal. Drove it about 20 miles today with no problems. Best of luck man!

thanks reelin68. will do.

thanks bigblue93. glad that worked for you. I did the same thing about a month ago with no help. my idle is also in as far as it will go, but my issue is also temp related and only happens with brakes engaged. i'll just have to drive it this way for now. used to idle so well, so I hope to get it back to that some day. one day, something will work. I hope. by the way, I also "burped" the coolant, which some have said can cause air in the lines.

a couple times you refer to not finding your IACV, next to your thermostat housing is a hose that carries coolant to the IACV, this unit is like another thermostat that can get gooped up, looking at you radiator leak sealer, this is the skinniest coolant passage so radiator debris collects there, one you tube video I saw showed a piece of blue shop towel plugging it up. the problem is it is under the throttle body housing and very hard to access, this is why an earlier response refered to many mechanics using carb cleaner to try and clean, it seldom works, and replacing the unit is hard, my guess is finding a person who has replaced it to see if there is any tips, tricks or in place tests possible, oh also it is important to get out any air from your coolant system or coolant will airlock itself out of moving through the IACV unit causing issues, good luck willwoff

Hey guys... me again:) Still haven't resolved the idle surge issue, but am pretty sure I have at least pinpointed it! A pdf regarding the auxilliary air valve says that if the idle screw is turned in as far as it will go, the engine should essentially stall. Mine doesn't. But, more importantly, I also did the test of removing the air intake boot (after engine is warmed) and taping over the hole on the bottom; replacing the boot, and recranking. In my case, the idle was too low to crank it, so I had to raise it back to what would be normal, and then idle and put my foot on the brake to test. When I did this, it didn't surge. So, I assume this means that the issue is the iacv/auxiliary air valve? I then had to put the idle screw all the way in again though, as the surging was too much to deal with once the tape was removed and the idle was far too high. I guess I now need to remove the throttle body and replace, or clean, the iacv. Unfortunately, I have no experience with this and will probably have to wait for a buddy to assist. If I had a second vehicle, I would go forward because it doesn't seem like it would be that difficult. I just don't want to screw anything up. Plus, I cannot find ANYWHERE to buy just an iacv gasket?? I've checked online, so I will have to go thru Toyota maybe? I've had some junk in my radiator in previous years, so this valve could be just clogged, or carboned, but a nice new one wouldn't be bad either...if it is indeed the problem. A new one prices out at about $120. Sure would've loved to have this over with, but I can't afford to turn it over to a shop. Sounds like it is at least heading in the right direction....

ps- the "hole in the bottom" I spoke of was inside the throttle body, in case that wasn't clear.

Willwoff I think I have the answer for you I have been working on my 1994 Toyota pickup 22RE for weeks trying to figure this out. I had Toyota Tech look at it he couldn't figure it out!!! WTF??? I been having the same problems you been having with your Toyota pickup. This weekend I took the throttle body off the engine and cleaned it thoroughly (however, it wasn't that dirty) I was surprised how dirty the air inlet that hooks up to the throttle body I scraped that gunk that was mostly right next to wear the throttle body hooks up replace the vacuum hoses (four) that go to the throttle body and also the hose from the valve cover. I took that inlet off where the thermostat was and it was clean and clear. Yeah I thought it was fixed. I also put a USED accelerator cable on to replace the original one (My truck has 450k on it) I maintain it well. I drive it in the morning it seemed ok when it heated up the idle was between 1500 to 2000. This was very weird the high idle was irregular. I did ALOT of research and I came to two conclusions either the throttle body or accelerator cable. I thought it had to be the throttle body just put a used cable on it RIGHT???? Well finally FRUSTRATED AND PI**ED OFF. I broke down and bought a brand new accelerator cable. I had my doubts this would WORK. I spent 10 minutes of my time outside today and what you know...THIS SOLVED MY PROBLEM!!!! I never thought it would in a million years. I found a blog this guy wrote on the same problem I was having. I didn't want to spend the $110.00 (I got a discount) on this Toyota Factory cable. Apparently the plastic wears down after years of use. the cable gets caught inside the plastic sheathing. I took this USED accelerator cable off a 110k wrecked Toyota truck. I moved it back and forth and it seemed to work fine to me. But, when it HEATS up the cable gets stuck inside the inner sheathing of the plastic and the car wont idle correctly!!! Man I spent a lot of money on this truck and to think it was the LAST thing I thought that was wrong with it!!! Good Luck Pete

I have a 1992 22re pickup and I just changed out motors for one with lower mileage. It surges really bad once it is warm and idles high when cold. I have tried the mass airflow sensor, coolant temp sensor, and checked the tps with an ohm meter. Any suggestions

Yeah clean your throttle body good and air intake.

john, I appreciate the input, but I believe I have pinpointed the problem. I won't know until I actually remove it, but I am almost sure I have a bad iacv. the problem is that I will have to remove the throttle body and the iacv and see if it is dirty...clean it...replace it...and then try again. I have also bought a new iacv in case I need it. there is a possibility that it is clogged with rust, etc. and that is why it is not closing when hot. this is a VERY frustrating problem for all Toyota truck owners who have encountered it because of the range of possible problems/solutions. soooooo...let me tell you why I think I have isolated the issue. first, I drove the vehicle until it got hot and started surging (mine idles fine when cold, but is a handful of surging mess when hot), then I removed the air chamber going into the throttle body and wiped the inside of the throttle body clean and placed duct tape over the holeon the bottom going to the iacv. I then put the chamber back and backed out my idle screw (because it was all the way in), The vehicle now doesn't surge and runs great. I even let it get cold and it started and ran fine. if I thought the tape wouldn't eventually get sucked into my throttle body or some horrific thing, I'd run it this way. however, there must be a reason why it has an iacv, so I will keep working on resolving the issue for good.

lsmith...have you tried to lower your cold start idle with the idle screw? if it is high enough to start the engine when cold, but not higher than necessary, it might stop your surging. if it still surges when hot, it might make it less. also, does it surge when the brake is applied, or all the time? try what I have described in my previous post and see if that helps. until I taped over the iacv hole, my idle screw was all the way in, and the vehicle ran fine when cold? it is a difficult issue, but try lowering your idle screw first, then try the tape test to test if you have a bad iacv. you can always check your pcv valve also, but I'd check the iacv first.

Willwoff, the idle screw doesn't help the surge any, it just raises/lowers rpm while surging. Where is the iacv? The brake also doesn't change anything

Willwoff, the idle screw doesn't help the surge any, it just raises/lowers rpm while surging. Where is the iacv? The brake also doesn't change anything. It also sounds like it has a miss

Lsmith, the iacv is located under the throttle body and has two coolant hoses attached. you can't really access it without removing the TB, which is why I have not taken it all off and checked it out just yet. but, you can remove the air chamber into the TB and you will see an opening on the bottom of the TB. By cleaning the area, and blocking that off with duct tape and then replacing the air chamber, you can test to see if this is causing your surge. I am told they are supposed to close when the engine is warm, and sometimes they don't which gives the same feeling as a vacuum leak. Make sure you do it when the vehicle is warm since that is when your truck surges, and you may have to adjust the idle screw after you block it off to get the idle correct for restart. If this stops the surge, you can then replace the iacv. you may have a different situation than mine, but it is worth a try as it can be easily undone. Just keep an idea of where your idle screw is at before you tape it off. good luck.

Sooooo, today I made a big discovery. Since I've been afraid to just pull off the tb, I keep making a step each day more than the day before. Today, I had previously taped off the iacv hole inside the throttle body, but was worried about it, and when I checked the tape was beginning to come off. Not good. So, I decided to pull off the hose on the front bottom of the iacv, which is a coolant hose. I did so because it has not been hot even when the engine is. As I suspected, it was COMPLETELY blocked with rust. The hose is so oddly shaped with so many elbows that it can easily get plugged. Truth is, no coolant has been getting into my iacv! After completely removing the hose and running a flexible but strong piece of coated wire through it, I was able to get water moving freely through it again. Before reinstalling, I unplugged the iacv port it was connected to, as well as the upper port it came from. I then ran water under pressure through the top port (the one behind the thermostat that often gets plugged) and the water flowed freely out the iacv!:) I took it for a long enough drive to know the valve must be working again, although it may need to be removed and cleaned better. I've no tach, so I adjusted the idle speed by ear, and it seems to running very good again. Hopefully it will continue. I also sprayed and cleaned the tb as much as possible. It was dirtier than I thought it would be. If it continues to work, I will still want to take the tb and iacv off and clean them really good. Wish me luck!:)

Willwoff, let me know if this fixed your issue. I have a 94 22re and have the same exact issue. I've taped the hole in the TB like you, but don't want to leave the tape there. I will need to try to clean or replace the iacv if this seems to work for you. Let me know something. I may have try to work on it this weekend.

cbsherri...yes, it did resolve my issue. in my case it was a blocked coolant hose going into the iacv, so I didn't have to remove it. feel the front hose connected to the iacv to see if it is warm once the engine is hot. if not, it is blocked. if it is warm, then your issue may be inside the iacv and you may have to remove and clean. i think you can test it by putting it in hot water to see if it closes. I feel lucky I didn't have to pull off the throttle body. good luck!

I haven't posted In a while but I finally found the problem. The EGR was being held open by vacuum. Pull off the vacuum line and idles fine

My hose was not clogged and I also tried the teflon tape on the idle scren and that didn't help either. I will probably have someone else look at it and try and replace the iacv next. Thanks for the help.

I just fixed my problem with high idle, and surgeing. following this discussion tried what you guys tried, finally I took my thermostat out, don't know why but this solved my whole problem, put a new thermostat in and had the problems return, so I took out my radiator out, it looked nasty as all hell dirty and corroded, so I got a new radiator, hoses, and all idle problems were fixed after I backed out my idle screw to where it should have been the whole time I had my problems I was unable to lower my idle speed because the screw was all the way in from my early attempts to slow my idle (this was an issue last smog check?), my guess is my reduced radiator flow from corrosion, did not let enough water past the Idle Air Control Valve (iacv) to get hot enough to close, which then made the computer try to compensate for by messing with my idle, so if any of you got this problem that looks like an iacv valve, and have a nasty radiator remember the little hose pulling coolant past the iacv needs enough fluid passage to work your iacv, the computer screws itself into a quiviring puddle trying to compensate for a hot engine and open iacv, and that is one reason a lot of us screwed the idle screw all the way in, trying to slow an engine idle surging issue. my truck is fixed, new radiator is worth it.

yep...radiator crud can cause a lot of issues. my hose going into my iacv was completely blocked, and I may still have to keep an eye on things as my radiator could probably use being re-cored or replaced. rust buildup and chips can also make an iacv stay opglad you got things resolved!en, and then it would have to be removed and cleaned.

So my problem went away on it's own, (at least for the last 2 days). I too had idle screw all the way in to try and help the idle surge issue, but Wednesday my truck decided to start idling correctly and then wanted to die on me everytime I stopped at a light because the screw was in all the way. I backed the screw out for now and it's idling nice. I haven't replaced or done anything to it, so I have no idea why it's working well now. It has been surging off and own for the 2.5 years I've had the truck. It would surge for weeks/months then run smooth for weeks/months and then back to surging. I have no idea what this thing wants/needs. Any ideas are welcome.

It will come down to the Idle Air Control Valve either being blocked or bad. You can try this fix in this video. For some, this works. If this doesn't do the trick, you will have to replace your IAC. https://m.youtube.com/watch? v=Y0Gfm2Dy7E4

I just bought a 1989 4 Runner with the sr5 v6.. it is doing the EXACT sane thing, only when warmed up, only when brakes are applied.. I've been restoring/ wrenching on cars my whole life, and Willwoff, you just saved me hours of diagnostics on my old yota.. I now know what exactly to check, and how.. Big thank you, sir!! ~Drew~

Drew...glad to help bro!:) I went thru months of research and none of the guys locally who would've charged me had any clue other than "might need a new this, or sounds like you might need a new that". As you can imagine, that can add up, so I had no choice but to keep at it. The good thing is/was that this seems to be a very common issue with these trucks and other cars in particular and eventually all the pieces of the puzzle came together...with others feedback. Hope it does for you also! (ps- even the manual doesn't mention this as a possible cause of surging?)

So i just fixed this problem15 minutes ago by taking a galvanized cable and running it thru the inlet that points toward the valve cover On the IAC.I felt it puncture the goop inside. Now she runs great.

Tell me if it helped or whatever. I just want to know if its dumb luck or if it works on other IAC.

Newer IAC's operate differently than the old style you have. If you read through all the above threads, your method was done by Willwoff when he replied to cbsherri. If you didn't read the above posts, then yes, you found it by luck.

I just wanted to confirm the wire trick would work as a temporary solution

Yes, that tube that plugs up has been somewhat of a common problem. Some people have found that over time, radiator sludge has plugged the tube causing the idle issue.

I have a 1989 22re and I tryed everything , then one day I tryed a simple thing ,, and ever since no more surging idol when brake is applied ,, let me know how u made out

mine does surge if the rad fluid is low.... check it out

I just fixed my idle issue that has been going on for over a year. As with Trevin above, my clog point was the small inlet on the IAC facing the valve cover. It's the opposite end of the hose running from the thermostat that is featured in the youtube video above. The hose wasn't clogged, and the thermostat side wasn't clogged, but I could feel something on the IAC side when I poked with a small screwdriver, but I couldn't get it to poke through. I grabbed a deck screw and just started twisting it in, and I ended up pulling out what looks like some white fiberglass- like material and a few small pieces of gasket. All told, it was less than a dime sized amount of stuff I pulled out after several attempts. Took the truck for a test drive, and it idles smooth for the first time in 18 months or more. I had to back out the idle screw a little because I had tightened it all the way down, but now it was idling too low. I don't have a tach, but I would guess it was around 400 rpm or something really low like that. I backed it out until I felt like it was around 700 or 800, and left it there. My truck is so quiet now! I can't believe this small amount of material was giving me such fits for so long! I'll probably have to take off the IAC and give it a cleaning at some point, as it may re-clog again in the future, but for now, she's running smooth! Good luck to everyone else who is trying to figure out the source of their problem, it sounds like lots of things could potentially cause the problem.

ok i got a 1991 toyota pickup and when i drive she is sputs really bad mean it runs but then it losses power to the wheels i've tried to look at the master air flow senser but i just replaced it now i think its the fuel injectors

In the case of my 1992 Toyota pickup the "ghost revving" of the engine appeared at the same time I noticed that, although the vehicle was achieving normal operating temp, the heating system was sometimes delivering warm air to cab, sometimes not. I discovered my coolant level was down significantly. I filled the radiator back up and the "ghost revving" problem immediately disappeared. My guess is the low coolant level was somehow screwing with the mechanism that enriches the fuel/air mixture when the engine is cold and leans it out as the engine warms up.

Mine was the Idle Screw was full of carbon. 85 22RE

I had this issue before, bought a new IAC off of ebay for my 92, and took me an hour to put it on. After that no issues, put 200k miles on it in the last 3 years and it still runs perfect.

This blog is incredible! I just bought my 93 Toyota ( RE 22, I believe) 73,000 original miles, one owner (Texas) solid as the day it was born. It recently started having the surging idle issues and by taking 40 minutes to read all the posts I have decent confidence in resolving the issue soon. Additionally the radiator has been spewing from the overflow when I park after driving a relatively short distance (10-20 miles) The previous owner provided all maintenance records and it seems several were r/t hoses, radiator caps and so forth.

Hey does anyone know what that port by the thermostat that the IACV bypass hose connects to is called? I unscrewed mine to check if it was full of crud and the threads on the bottom were all corroded and crumbled off. Need to get a new one of those things but I can't find a diagram that tells me what the heck it's called! Any help is appreciated. Also how do I get the threads that crumbled down in there out? is there a flush I can do to avoid running it through the system? Thanks.