setting timing marks on 97 Silverado w/5.7

you need a snanner to set ignition timing cam retard should be 0 degrees was the truck missing or roughing smooth when the check engine light came on? Before u messed with it

It would pop occasionally and I have poor mpg approx. 12 mpg, but it runs fairly smooth. I tried to set it back where it was but I dont think I'm at the same spot on dist. cause its running a little rougher now.

need to get timing set right and running properly before diagnosing O2 sensors .

john you're way off . this is an OBDII system , the only way to set the timing is to use a scan tool, there is a procedure to follow , if it's not done the right way it will never be right.

It has a DISTRIBUTOR there for the DISTRIBUTOR has to be set to 0° for the electronics to do their job properly. You have obviously never replaced a distributor on an OBD II vehicle. Its just like replacing a distributor on an OBD I. Even the 2000 and newer Honda's have to be set properly when the distributor has been replaced. Yes there is a procedure to be followed but the timing has nothing to do with a computer. I explained the procedure ask any mechanic and they will tell you if the vehicle has a distributor whether its carbureted, TBI, MPFI, or SFI the timing is adjusted by turning the distributor till its flashing cylinder 1 (or 6 on a GM) at 0° with the electronic advancement wire unplugged.

yeah ok !

He even said he changed the timing and now can't get it back to where it was. If you don't know what your are talking about then don't include yourself in the discussion. Its guys like you that have made cha cha a worthless service. You think because you know how to check your fluids, tire pressure, and read a car magazine at a dentist once that you're now an expert.

John is absolutely correct. This sets baseline.. This is the procedure to a tee. I know if you don't unhook this wire timing will drift as it is then being contolled by the advance. I believe John's reputation speaks for itself.

Never could find the wire John refered to. I did a tune-up recently though and noticed on the inside of dist. cap that it was firing just at the side of the pronge (or what ever they're called, where the coil sends the spark to the plug?). I assumed it should be hitting the middle so I advanced it a little. It doesnt run bad, it just doesnt get the mpg I thought it would after rebuilding it, as I was getting 12-14 in town and 15-17 on longer trips before I had it rebuilt, so I thought I would get at least that? Maybe its still going through a brake-in period as I still only have about 7k miles on the rebuild. I appreciate your input and advice, but need to ask for a favor? Let up a little on the dumby trying to fit in even though he was giving incorrect info. Thanks again.

The number one reason for a check engine light on is a loose gas cap or a bad one.

John is correct with the obd1 however on a 97 obdII, that distributor should not be adjustable, unless someone cut the tabs off the plastic dist body. There also is not a wire to unhook on 96 or later to set timing. The hold down bolt goes thru a slot in the dist and you can only adjust the dist by about 2-3 degrees, just the slop in the hold down bolt to the slot. These are difficult to set because of that, trying to seat the dist gear and the hold down slot at the same time because the distributor will twist as the dist cam gears mesh. YOU MUST USE A SCAN TOOL TO SET TIMING ON VORTEC 5.7 Here at our repair shop we have the factory GM tech2 scan tool. You will be able to read the timing degrees with that. If the timing is off by more than 2 Degrees it will set a check engine light. Once you have the timing correct, you MUST do a procedure called (cam crank variation re-learn). You MUST DO THIS WITH A SCAN TOOL. In the function with the scan tool, with the engine running, scan tool will tell you to quickly rev the engine to 4000rpm basically flooring it in park, and immediately let the engine back down to idle, and then if completed correctly, it will display that on the scan tool. Even if your timing is correct, you must do the cam crank variation re-learn if it has not been done yet. If you ever touch the dist once the re-learn is done, you must do the re-learn again. Sometimes it takes a few times to get the variation re-learn to accept, but also be carefull because sometimes, during the relearn the rev limiter is disabled to allow the engine to rev high enough for the relearn. If you put your truck in park and are able to rev it up past 3500rpms, then your re-learn IS NOT done.

im having the same problem by the book n Chevrolet say the mark needs to hit the 8 imprint I done tried n tried nit wont it ,it will get close to it but I start the truck and automatically the check engine light comes on sayn crank n cam corillation ,,n im all out of ideas!!!!!!!!!!!!!!! what kinda scan tool are u talking about cus I have a 230.00 one n it doesn't give me that option!!

snap on .

TEch2 is the factory GM scan tool and that is what we use at our shop. That $230 is a code reader and nothing more. There is a reason that snap on, cost 2500-3000+ along with tech2 or other scan tool.

There is no wire to disconnect on the year he is talking about. Late 80's and early 90's had the brown wire that needed to be disconnected, but with the spider injection, the timing is controlled by the computer.

Wow ! - Almost two years to figure out that a 1997 5.7 Distributor does NOT have a little wire to unplug ! Mechanically the engine must be set to Top Dead Center. The electronic timing (advance or retard) must be less than + or - '2' or the Check Engine Light in turned on. This can be set approximately by setting the flat front face of the distributor and the flat back face of the throttle body parallel with each other. For more precise setting of timing advance/retard a scan tool of some sort must be used. With the development of modern smartphones that run apps, a less expensive option is available with Bluetooth OBD2 plug readers (ebay) and Torque (Android) Bluetooth App (Google Play) -- total cost under $30 (if you already use a smartphone). Way Too much Posturing and Misinformation on this Site ! No one benefits from HOT AIR.

Yeah this John guy who has the mark as "most helpful" answer on here is sadly wrong for 96 and up, but then again it was more helpful than Rucko's need to bash him than to give the correct timing procedure. Thanks Kurt for finally clearing things up. The 96 up definitely doesn't have the timing advance wire that needs unplugged as it is fully controlled by the computer. As for the relearn method I have yet to see it on my MTG 2500, will have to look into that next opportunity that I have to do so.

Hi! Read and appreciate all the in put, been looking for a way to set up the distributor to"0" by rotating the distributor at top dead center to the 0 setting (precisely). This was done with our air cooled VW and motor cycle engines mid 60's 70's.

could a worn out timing chain give the same fault,?,mine also misses out,just after you have the throttle set at speed then let off then it misses,my garage man siad it was all six fuel injectors clogged

A good code scanner can help alot.but popping off the distributor cap and twisting the crank back and forth while watching the rotor button can give you a idea if you got slack in your chain.

when i set the timing on my vortec 350 I use a junk distributor with the cam gear knocked off to line up the oil pump rod so my good distributor will fall right on the number 8 mark,and remember guys the mark on the intake and distributor line up right to

I must have a special 97 350 vortex. Bought it new but there's no #8 cast in distributor base and no marks on the shaft. Does dimple on drive gear have a magnet? I may have installed gear 180 out

No magnets,there should be a 8 very small.and yes you can install the gear 180 out.I did once

I know what the problem is, am mechanic, need to clear fault codes. the computer is still showing the faults before rebuild. I know how. You should take it back to who rebuilt it. They should know. Don't worry about it, if oil light or battery, brake indicaters are not showing it is ok. If you have gauges rather than dumby lights, it should run around 200 on tenp, 40 to 60 is average iol press.

The timing is computer controlled the gear on the distributer or camahaft or possibly a loose timing chain could

ok...my snap on...which was bought used..no book, so im learning as i go has me at 2 on the cam retard, but it still shutters and shimmys in drive...tachs slow in park...the distributor is turned counter clockwise at about 5-7 degrees more than it should with the 2 reading..i put a rather new engine in it lately and have been struggling with it for a long time to get her road worthy again...is it possible she is a notch off like the older ones and still run, but crappy and still hold a 2 on the cam retard...??? it seems to smooth out a little when the engine warms up good, but still too bad to be actually road worthy...ive replaced just about all the sensors...computer bad mayby ? anything helpful will be greatly thanked.

@skilletlegs: I changed a 5.7 on my 97 silverado almost a year ago..I was careful to put the distributor at the proper TDC mark. The engine ran, but very rough. I towed it to a friendly mechanic who had the high end snap on tool, and he adjusted the cam retard to zero...He explained that while I was very accurate in putting the distributor back in, it was vitally necessary to use the snap on tool correctly, as this actually sets the ECM computer to the proper cam retard...he showed me this in principle by comparing the readings from his scanner before, then after, as well as the fuel trim and other performance values....all associated. what I am saying is, even though you have the tool, it might be a good investment in having a experienced TECHNICAL mechanic to show you the ABC's how to use it properly...AND explain the WHY...much of this is not intuitive to me..it really helped understand the importance of the difference between buying a very expensive tool, versus just having a good mechanic do the work for me..that was my experience. I never bought the expensive tool...have never needed it since that adjustment was made. Would not believe it would ever be necessary, until the day my timing chain becomes muffed, or I change the distributor at some future date...hope this helps...

where is this wire located on a 97 chevy Silverado 1500 Z71

where is this timing wire on a 1997 chevy Silverado 5.7L 1500 4WD

I have the factory shop manual in front of me, and i also have replaced my distributor on my 1997 vortec engine. you can not time without a scan tool. you can get it close but not exact. engine must be at operating temp rpm must be over 1000 and it is to be set at 0 no more than +2 or -2 . some replacement distributors are able to be turned when in place. clear codes if the code p1345 does not come up you got it.

so what happens if your timming keeps going off? my gmc i keep reseting it but nomatter wat it goes off

Kurt is correct, John is wrong. You need to make sure the distributor's gear teeth, rotor are in the correct position, set the timing to zero degrees (mechanical part. After this, is where everyone seems confused and with good reason, you have to do a procedure called (cam crank variation re-learn). You need a GM or China tech-2 scanner! When this done correctly, the cam position sensor will be at zero degrees. Took forever for me to figure this out. YOU NEED SOME KIND OF SCAN TOOL TO DO A PROCEDURE CALLED (cam crank variation re-learn).

Your all smoking that good shit,feet power brothers and sisters,nothing but leg POWER will get you anywhere (just gotta leave a little early)

Ok when setting up a new dostributer how do i set exacly at 0 degrees .ive found comp on 1 at tdc aimed the rotor exacly at it snugged it down ,plugged in timing light run it up to round 2500 and set it at 34 degrees because its a complete new jegs crate 350 ,But it has a misfire i cant figure out .oh yea its on an airboat so its basicly sitting ona engine stand ,ive done everything to try to fix it hence. Brandnew carb edelbrock ,new distributer cap rotor ,flamethower ,spark plugs and 8 millimter wires done compression ck all at exacly 175 ive changed the distributer 3 times already testing it all the same steady bop bop bop at say 2300 to 3200 then kinda levels out or my prop screamin makes it seem like its firing right but wen i left off its back to misfie. What the hell am i missing ??????

I'm having a similar problem. My time is set right, but every time I plug the timing wires back up it goes to missing. Also you cant accelerate?? It goes to spitting. You can unplug the timing wire located on the firewall and itll put like a kitten. Any ideas??

I dont have the answer my 96 yukon 5.7 vortec has new crank @ cam sensors coil modgule cap-rotor wires plugs fresh fuel 55 psi ,compression 155 12000 miles on new GM engine dead time motor , cranks like its 50 degrees adv. no start and just put a new ECM in it all fuses good NEED HELP LARRY

Can’t the check engine come in and start throwing random codes that aren’t true if there’s a loose vacuum line somewhere too? I had a new motor installed and this happened to me. .. it ran like crap sputtering acting like it was running rich and loading up and then it would run fine and then run like crap. 4 mechanics could not figure out what was wrong. Replaced fuel filter, punched through the catalytic converter (due to a 420 code) I replaced the bank one sensor one O2 sensor TWICE, once on the side of the road in a parking lot pulling my car on to a curb to raise it enough to get under it. Thank god I had my O2 socket with me) I replace the fuel pump (in a shop). Finally a smart mechanic after having my car for 4 days found a loose vacuum tube at the bottom of the engine and my cars ran perfectly ever since. I put 4000 miles on a new motor with it throwing every type of code. Punched through the catalytic converters for no reason. Now the only code I get is 420. I purchased an OBD reader because of it. Mechanics are surprised me being a woman even have it. But it helps me to do research before I take my car in for repairs and that way I won’t get ripped off. I was even offered a job at a shop. lol.

One thing I see missing in EVERY response is when you use the scanner to set timing on an OBDII Vortec, you must have the engine at high idle between 1000-1200 rpm for pcm and cam sensor to work correctly. Setting it at idle will Not work as cam sensor and pcm are not advancing or retarding timing as they should.

Thanks everyone for all your help. I too am having a hard time with my 97 5.7 vortec getting the timing set right. My mechanic has the snap on verus and we got the dis at -2 and running ok but a bit sluggish. Tomorrow I will set timing with idle set at 1000 to 1200 to get it set to "0". Much appreciated to all

My question is where do you get the scan tool?

Hmmm. I just swapped out my distributor with a new one. I had the battery disconnected the whole time. Took it out on the road. Running about 40 mph, I floored the gas pedal, it revved to 5000 rpm once and after that it didn't rev that high again on the next few stomps on the pedal. Mine seems to run fine. I got a aluminum billet distributor with brass terminal cap.

Me and my husband have removed distributor on 98 suburban and 99 k1500. We got them back in and eventually in the correct position without a scanner. It takes some patience turning the cap till it's in the correct spot but it can be done. We did ours years ago and run just fine. Not everyone can afford scan tool or pay a shop to do it either. So this is why you learn to do it yourself. This is why we drive 20 year old vehicles cause we can fix them ourselves. Even when the pros tell you it is not possible without a scan tool. Because it is. The distributor was changed on suburban 2 years ago. At this time it has 297,000 miles and runs great!

Workman76 Same here. You just gotta know the right way to put the distributor back in. Also helps if your harmonic balancer is marked right.

this is not an answer but a conformation that my 97 k1500 does not have this wire as well. i am more perplexed after getting a maf and a cam error code po340 and po102 simultaneously and my replacement of the both has rendered no solution i am not a ASE cert mech at the time but i was a long time ago i have toad diagnostics and professional programming software. my problem is every time i relearn it drifts back to crap its like doctor jeckle and mr hyde went through wiring harness checked everything including a second sensor for both no avail 400k on pcm starting to think its a lil tired new motor ran freaking great 25k into it and it had a new distributor put in before it ran at shop. now this truck can literaly run and run pretty well with both maf air temp and absolutly no air filter lol smoke tested for vac nope strangest thing ive seen in a minute

is there a independent grnd or something im missing for pcm ? could the distributor have failed? got me stumped i feel this whole problem is completely electrical with no sensor failure at ajj