Low idle slight stutter

Are you running a new set of A/C delco plugs and are they all firing ? and can it be possible there is an exhaust leak ?

Yes full tune up not sure on the firing but there is no hesitate on driving it. Full power before this low idle it wad loping and stalling that's when I dropped money and replaced every sensor and redid igniton timing now just a really low idle

When inspecting the base timing, is there a procedure on yours for disconnecting a spout wire or pip signal type wire ? The low speed at idle and the noise makes me want to turn your distributor till it runs good.

You have a new fuel filter, and your cap is not full of ashes, right? and a/c delco wires?

After rechecking your work and the basics, that has TBI right? Is there a jobbie in the throttle body assembly with a plunger. You used to remove them and clean them and press the plunger in, then reinstall them and have them recalibrate when the key was turned. It meters air to bypass the throtlle to help control idle speed, it's one of the system prechecks before a tunup

If this helps at all when I start it it will crank 4 or 5 times then fire if I shut it off and try again it will just crank never start shut it off try again 4 or 5 cranks and it will fire

Don't waste too much money trying to track it down. Most tbi chevy I've owned have started doing this. It make be worn valve train but recently I've contributed it to high ethonal content in fuel. These trucks weren't made to run that crap and never will be.

Hard starting too then, noticed it cycles where there is actually a no start at times. what does it lose during the no start sequence? spark, fuel, compression, or timing ? It has to be one of those 4. (like it leans out?) This is an if theory, loses injector pulse ? Or the injector malfunctions, or the injector needs professional flush chemical cleaning? You used to be able to test and check pattern, replace screen, and get a cleaning at napa or dr. injector. with it off the car.

valve deposits and combustion chamber deposits can be working with other factors to take away your volatility of fuel , to use andrew's idea. were your previous plugs fouling with ashen deposits or gas additive build up? Like coated thickly with layers of ash or like after adding techroline? and is your fuel pressure in spec ? holds rest pressure? delivers volume ? I know it is not the easiest set of tests, but old parts can be failing slowly or partially failed. But read all this again because I haven't really been getting any answers.

You dont have hoses that fit loosely ? grommets that are hard , or hoses that are baked and stiff, do you ? like pcv leaks vacuum ? fits loosely, is aftermarket and different from A/C delco ? These are causes of hard start, and delayed start, and no start. Hoses at the front, base of the TBI need to fit snug.

How many inches of vacuum do you read at a manifold source at idle before and after correcting those things? Just brainstorming for a 20 year old truck that I cannot inspect or listen to, or view the injector pattern.

We're Gunna do a fuel pressure test tonight I'll update yall we did the ignition timing which stopped the surging issue I had before now just low idle hard start

Also is there a way to have this app notify you if someone answers

It just emails me. But I cannot walk too far from it.

Next thing I was going to ask after the readings is, does it have a baggy timing chain or an intake leak ?

This all started after spraying motor down after mudding instant idle issues wanted to stall and would at red lights and stops then it started surging redid the ignition timing fixed the surge now it's just low idle with stutter and hard to start so really it could be a number of things .... if my ecm was bad wouldn't the truck not run At all

The washing can leave trapped water somewhere. You want a a/c delco module and pickup in your distributor, and ecm issues with ck eng light or no light should be given, and the code reader can be helpful. If you believed your usage had immersed the ecm, that can damage things. A used ecm can be had very inexpensive at a u-pull-it type yard. I do not understand if the cause was old fuel pump failure or service code related at this point.

Check the Pig Tail connection to the AIR IDLE CONTROL Sensor. This will impact the IDLE if the connection is bad - This will cause spike and low idling if the four prongs are wired wrong or not making proper connections. ABCD AB is Coil 1 and CD is Coil 2. Just trying to help.

If you still have the problem, or anyone else does, I had a similar problem with only 95,000 miles, and i threw every sensor I could think at it, with a new fuel filter and fuel pump, and then it turns out the computer was bad, so I was getting error codes for parts that were fine...

I will try another ECM.

Holy christ. I was searching this up for weeks. Ive changed out tons of stuff. Fuel filter fuel pump spark plugs and wires. egr pcv cleaned out all the throttle body inspected everything. And she still bogged and almost died ( sometimes would just die) and today i was leaving work and she had a ton of power for like 1 minute. So today i got home and i. Slapped my head and thought what about the timing lets take a boo at that... It was waaaay the hell out to lunch. Absolutly ridiculous. I set er back to a hair above 0 degrees and took her for a bip. Almost laid rubber peeling out of the park. I really hope this is the case for some of you as my heart was bumping like crazy when she went

timing has to be right on for these tbi models - I put a brand new motor on my 1995 chevy van(stock setup 4.3, just built with current oem parts that have way better tolerances) - I replaced all the sensors, vacuum lines, everything. it still had a idle range random misfire that didnt set the check engine light. the low idle setting(adjusting the torx screw on the throttle body, with the jumper in the harness under the steering column and iac disconnected) is mandatory if you changed alot of parts. it ran better, but still wasnt solved until I found a good mechanic with the official obd1 scanner setup to check the air/fuel ratio thru the rpm range, and adjust it on the computer - then perfection. the whole while it ran perfect above 2500 rpm, it was only missing in low rpms, with no load. the only upgrades were accel 5000 plug wires, msd coil/dist. cap/rotor, accel icm, and ngk iridium plugs - for a stronger spark, and made a noticable difference in how smooth it ran, and it can go about another 1000 rpms higher than stock. but, the main thing to get rid of the miss was to have someone capable check the fuel combustion on the diagnostic machine - he showed me the numbers, and could tell if it was getting too little/too much gas at each cylinder thru the whole rpm range. it was also easy to see if all the sensors were working properly - $200 to a good mechanic will save way more than replacing parts that might all be working, and just need the right adjustment in the stock pcm

Did you ever find the issue with rough idle.

Try removing the 2 injectors from the TBI and there's one fine small plastic screen on the bottom of each injector. These will be dirty. They catch smaller particles the iinline fuel filter and screen inside the fuel tank miss. The right fuel pressure doesn't mean anything if these are dirty. It causes the injectors to have a bad spray from lack of fuel pressure and it's not as prominent in slightly higher rpms. And possibly replace o2 sensor with OEM correct.

Im having an issue with the truck, it runs fine at higher rpms, but if im just barely on throttle a little it bogs and starts to kinda sound like its cammed, and it will startup then stall at times, I was pulling into school today and when I let off it tried to stall but I saved it and had to hold it at about 1500 rpm before it wanted to stop and it started running very rich it seems like because it was smoking out the back when it started running really rough, I replaced the IAC, fuel pump, spark plugs, wires, fuel filter a couple years back, took apart and cleaned the throttle body and put new gaskets in it, PCV valve, and 1 of the coolant temp sensors and Im kind of at a loss on what it could be.

Are you ready have a chevy 95 c2500 5.7 liter Tbi have all the symptoms found the problem with all 5.7 liter TBI system have the same problem crazy took me three days to pin point the problem with the PCM 32 pin problem within the harness within the harness firewall IAC TPS and ICM wiring have a wiring problem builds a magnetic field which Dc wiring develops behind the distributors fire wall pull on it and see the engine reacts when pulled and TPS high and low range reacts period changes from rough to idle calms down