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2000 Chevy 4.3 No Spark At Plugs

Discussion in 'Builds and Fabricators Forum' started by 47v6, Mar 19, 2022.

  1. Mar 19, 2022
    47v6

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    2CBB15AF-4F05-40E9-9D42-54C49732C196.jpeg 390F0142-7FD4-4A5B-902E-FDE31169C486.jpeg I am attempting to start my 4.3 transplant into my 48cj2a. I have no spark at the plugs. The distributor got moisture inside the cap and rusted pretty good. I wire brushed it.

    Question I have is, would the rust particles create a failure of the cam sensor to indicate no signal break?

    I think I am going to order a new distributor body and cam sensor anyway.
    Thanks.
     
  2. Mar 19, 2022
    jeep peep69

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    Definitely replace or clean the cam sensor.
     
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  3. Mar 19, 2022
    SFaulken

    SFaulken Active Member 2021 Sponsor 2020 Sponsor

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    Man, I honestly don't know, I've never actually worked on this particular sort of GM ignition system, but if that were an HEI or Duraspark/TFI, I'd definitely be looking at getting that rust cleaned up and probably replacing that cam position sensor.
     
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  4. Mar 19, 2022
    timgr

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    What kind of sensor is it? If it's a VR type you should be able to spin it and see the needle move on an analog voltmeter, or see it on a scope. I would expect continuity through the pickup coil too.
     
  5. Mar 19, 2022
    47v6

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    I’m just going to replace the whole thing with an Amazon 40 buck special. The rust cannot be good for it.
     
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  6. Mar 19, 2022
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    While you are doing this, also as a precaution, check the crack position sensor and circuit wiring.
     
  7. Mar 20, 2022
    nickmil

    nickmil In mothballs.

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    This was a common issue with the 4.3 and 5.0/5.7 Chev V-&’s of that era and a little earlier. I think we had a half dozen rusty cores at work at one time that had been replaced under warranty. Check the incoming wiring closely before replacement.
     
  8. Mar 20, 2022
    47v6

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    Thank you both for replying.
    The wiring harness is all brand new from Howell. The distributor cap was cracked and as it sat, moisture accumulated. The engine was always covered. When I replaced rtes cap, rotor and wires, I was shocked to see so much rust.
    The crank sensor is suspect, as it looks to me a replacement and is covered with rust particles. It looks to have a magnetic component that works with the distributor ring as a kind of prox sensor for timing.

    The new amazon special seems to come with cap/rotor/distributor body and crank sensor.
     
  9. Mar 20, 2022
    47v6

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    New distributor installed, still no spark at plugs.
     
  10. Mar 20, 2022
    jeep peep69

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    Do you have power to the distributor? Is the coil good? Not sure if this year model has one
     
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  11. Mar 20, 2022
    Twin2

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    ignition coil . my old van had one go bad . wouldn't start on damp or rainy days
     
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  12. Mar 20, 2022
    jeep peep69

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    Bad ign. Module? I know this is a conversion but is the check engine light illuminating when you turn key switch on it must to make spark if not you may have a bad pcm
     
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  13. Mar 20, 2022
    scott milliner

    scott milliner Master Fabricator

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    I just went thought that with my 4.3ltr. Not a fun.

    Also check those Ground wires. I had mine connected to the Bell housing bolt instead of the back of the head. :banghead:
     
  14. Mar 21, 2022
    47v6

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    I do not have the check engine light hooked up. I was just trying to get it running to motivate me to fix all the small stuff. Do I really have to have it hooked up to run? The PCM is from Howell and supposedly reflashed to run a manual transmission as apposed to the 4l60E.
    I do not have a ground to the back of the head, but to the front of the block. It goes directly to the battery.

    I did check power and ground at teh connector to the ignition control module. Both are good. To check the coil I apparently need a spark tester. I dont have one. To do the other tests I need an LED light and have to make a tool.

    Instead of doing the actual testing, I threw parts at it. The new coil, ignition control module and crank position sensor was 58 bucks shipped. The new distributor that came with a cap/rotor and cam position sensor was 41 bucks shipped. Its also all aluminum instead of all plastic like the old one.

    It will be here by next weekend and then I can be irritated all over again!
     
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  15. Mar 21, 2022
    45es

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    You do not need the check engine light to make it run but it does tell you the PCM is receiving battery voltage. Depending on what PCM you have, it can help lead you to the problem. When Howell re-flashed the PCM, did they turn off the anti-theft system? If not, that could be the issue.
    The electrical ground does not need to be at the back of the head. GM uses the location as a convenient location for the wiring systems. The ground at the engine must be a sound connection though. If you look at a GM wiring diagram, you will see the engine become the central grounding location. You will be wise to assure all your electrical systems ground off of the one location. At the moment, where is the PCM's ground connected? It should be connected to this location. As an example, on my jeep, the battery negative cable terminates at a bolt at the rear of the right head. From that location (bolt), ground leads connect to everything else such as frame, ECM, instruments, lighting systems, etc.
     
  16. Mar 21, 2022
    47v6

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    I specifically told Howell to disable VATS. It should be done, but I have no way to verify it.

    I have the ground to the front of the block with a star washer. The rest of the grounds to body and frame are connected from that wire that leads directly to the battery. Is there an additional ground to the PCM that must be done? Does the PCM body need a ground as well? The Howell harness was labeled very well and I have connected everything as directed.. At least I assume I have.
     
  17. Mar 21, 2022
    45es

    45es Member 2021 Sponsor 2020 Sponsor

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    It sounds like you have addressed the grounding system properly. I am sure the Howell harness connects the PCM to all it's respective systems and this of course includes PCM ground. The PCM body does not need to be connected to ground. Which PCM are you using? When you turn the key on, what do you hear? You should be able to hear the fuel pump cycle which would be an indication that the PCM has received power and is preparing systems for engine start.
     
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  18. Mar 21, 2022
    47v6

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    Fuel pump turns on, has fuel. I have not tested it to ensure it has greater than 50LBS. The PCM I am using is the same style used in the astro/safari/s-10 of the era. I purchased this one from Howell and gave them my specs with the idea that it would be plug and play. We know their FI for the dauntless isnt though..
     
  19. Mar 21, 2022
    jeep peep69

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    You would have spark even if the vats was still enabled all it does is shut off the fuel.
     
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  20. Mar 21, 2022
    45es

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    Sounds like you are back to a defective ignition component such as the ignition control module, coil or a faulty electrical connection.
     
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