2000 silverado 4.3,replaced intake manifold gaskets engine wont start

Discussion in 'GM Powertrain' started by tattooman, Oct 7, 2010.

  1. tattooman

    tattooman New Member

    hi i replaced intake manifold gaskets ,engine started but was missing i took distributor out and put it back in now wont start and i have a burning smell ,took it out again think we set timing right with 1 piston tdc on compression stroke put distributor back in with rotor pointing at the mark on distributor about 8 or 9 oclock still wont start ,was running no problem before i changed gaskets only problem i had was if it got damp and help been at it a week now and im in uk that does not help thanks dave
  2. stephan

    stephan Rockstar 4 Years 5000 Posts

    Hey Tatooman;
    Make sure that when #1 is on compression and the rotor is pointing at the mark on the distributor housing that this is also where the number 1 plug wire is also attached on the dist cap! I have seen #1 wire out of position on the cap many times when plug wires have been replaced in the past. If "Joe the mechanic" got the sequence wrong 5 years ago when the first set was replaced, every one else would have followed suit behind him.
    As far as the eng missing after the gasket replacement, but before the distributor R & I, that might be a hose left off or wire loose etc.

    Did you disconnect the wire to take the distributor control away from the computer while you set the timeing? On my truck this is a small brown wire with a black tracer and is near the dist. along the firewall. Yours will probably be different color but you must disconnect this wire to take the computer out of the loop while you set the timing or else the computer will try and correct where you are trying to set it, and it will be so far off that it will not re-start.
  3. ejohnson03

    ejohnson03 Epic Member 5+ Years 1000 Posts

    X2 on the Distributor connection to the PCM.
  4. tattooman

    tattooman New Member

    hi stephan i had a look for the wire could not see it phoned a garage miles away and he said he thinks they dont have that on a 2000 4.3 silverado ,if they do it may be my problem so any help would be great ,as i said did gaskets and it started up run for 30 min but missing and would only just pull away ,took distributor out and put it back in all down hill from then wont start thanks dave
  5. stephan

    stephan Rockstar 4 Years 5000 Posts

    Yes I'm 99% sure it has one. Unless you have disabled your computer, it is controlling your timeing and you must disconnect it to set the timeing. I'm sure this is why it started BEFORE you removed the distributor, but wouldn't start after you reinstalled it & set the timeing because you were trying to set it and the computer was counteracting what you were doing so now it is WAY OFF & won't start. Here is a link another member posted where you can find a wireing diagram for your vehicle to see what color your wire is to disconnect. It takes you to an online library.

    click on the chilton library.com logo
    type "nwls" for the password
    click proceed

    Or click on this one if the other one doesn't work. There was some question as to how long these links are good for as they change them from time to time. http://infotrac.galegroup.com/itweb/...40539003520151
  6. stephan

    stephan Rockstar 4 Years 5000 Posts

    Hi Dave,
    Just thought of smth that might help you find your wire. On mine there was a black dust cover on the firewall that covers 3 or 4 relays and a wad of wireing. The wire should be behind this cover if the last mechanic put it back properly. I'm not sure how many miles your rig has on it but chances are the timeing has been set at least once in its life so this wire should have been sleuthed out from the rest and when done was probably left right in the front of the rest of the wire wad. Look for a wire with a small connector in the wire. This is made for easy disconnect. If you still can't find it, look at the Chiltons at the link I left you and find the color code for it.
  7. tattooman

    tattooman New Member

    hi stephan i have had a play with truck today set the timing it was 180 out started first turn but not running right have driven it but its like its not firing on all cylinders,i have new plugs in ,dont know if timing just out a bit ,could not find the wire if it has one to bypass,as i say it was running ok before,i dont know weather to take distributor out and try it one tooth ever way,any more help would be great its a 2000 silverado 4.3 thanks dave in uk

    ---------- Post added at 01:20 PM ---------- Previous post was at 01:01 PM ----------

    hi cant see chilton library.com logo
  8. stephan

    stephan Rockstar 4 Years 5000 Posts

    Don't pull the distributor out again Dave. You have got the distributor close now because it starts, so it just needs a little adjustment.

    Do you have smog controll laws in merry ol' England? If you do then I'm sure your vehicle has this wire on it, and the computer controls the timing.
    Try this, hook up your timing light and see where the timing mark is. Have a friend move the distributor a little bit while you watch the mark and tell me what it does. If it is a smog control engine it has computer timing controll on it, & the computer should try & move the timing mark back to compensate for your friend moving the distributor.

    I will go & try the chiltons site and see what I can see there.

    I went to the library and they wouldn't let me in either, but I found a wireing link @ another place. Go to this one and sign up fill out the info and they will send you a link to help you trace out your wire. It says it's FREE but I didn't sign up yet so I don't know..

    Edit*** Ok Dave I went online and filled out the paperwork so they would give me the link to the wireing. Here it is below. Just enter your vehicle & model etc. and look for the distributor pcm wire. If I have time I will look for it and post it here....cheers
    Last edited: Oct 11, 2010
  9. tattooman

    tattooman New Member

    thanks for all your help have looked on the link cant see my year silverado 2000 4.3 1500 model but looked at the other years and they have it think the SUBURBAN is like mine and cant see it on that ,as for my distributor it does not move,going out to have a look at it now it started up one turn again today

    been looking at truck today pulled plug wires one by one with engine running ,got to number 5 and pulled that no change in engine sound all the rest had a change when pulled ,so its number 5 ,took plug wire from one that worked ok put it on 5 still no change in sound on engine ,got spark at number 5 ,so im thinking could it be dirty injector on number 5 from where i cleaned gasket ,drove it to a garage he said the same number 5 runs the same with plug wire off .
    Last edited: Oct 11, 2010
  10. stephan

    stephan Rockstar 4 Years 5000 Posts

    That's good Dave, you're making progress. Switch out the injector with another and if it fixes #5 then it's just an injector problem. I don't think you got #5 problem from cleaning it, I think maybe if the problem on #5 is NOT the injector then it might be a vacuum leak at the gasket. Spray some carb cleaner around the gasket and see if the idle picks up and smoothes out.
    Also check the wiring on #5 injector. Wire(s) could be loose in the wiring connector and when you click wire connector onto the injector, the wire(s) gets pushed back into connector plug and does not make good contact with injector.

Share This Page

Newest Gallery Photos