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Chevy Car Question

Discussion in 'Chevy Trucks' started by MickiRig1, Nov 11, 2007.

  1. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    I have a 2000 Malibu and a Co-worker has a 2002 --> 70k on it both with the 3.1 - V6.
    Do they have ignition modules or does the computer do it?
    AutoZone got a code for multiple misfires. He says the cars seems to hit the wall at like 2K rpm. I had him change the wires,spark plugs and he decided to replace the coil packs. Cleared the codes, 2 days later no codes but now runs the same as before.
    I changed out the fuel filter for him, & new pcv before he installed the other stuff.
    I am going to put my fuel pressure gage on it tomorrow and see what I find.
    Any thoughts on what it could be? Common problems? All else fails we start testing injection and emission components.
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Micki they do in fact have an ignition module, but they're totally controlled by the PCM....and they rarely fail. A much more common thing on them is a weak fuel pump just like you touched on..

    They need a minimum of 45psi at the rail but they will run with as low as 35psi but they wont run good and will run out of fuel at a low RPM, which will cause it to do exactly what your describing. I'd definitely get a pressure gage on it and take it for a ride to see what kind of pressure it has under load.
     
  3. R&R Repair

    R&R Repair Junior Member
    Messages: 28

    I've seen this before on many other vehicles and 9 out of 10 times it has turned out to be a failing coil. Or individual coil pack.
     
  4. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    All the coil packs were replaced along with the wires and plugs.
     
  5. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    I had him run a can of SeaFoam through it too. Before the problem with the car he had done nothing to it but drive it and change the oil. If it is fuel pressure, I am going the change the pressure regulator first.I did find the vacuum line was damaged to the fuel pressure regulator a month a go. We repaired it. I have heard the pumps are like $400+ for a new one. I have not checked yet. His Wife wants him to trade it in and get a new car. It's paid for, he does not want a payment again for a while. We say fix it and run her into the ground for another 100k miles!
     
  6. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    A genuine GM fuel module assembly is around $400..but you can get an aftermarket one for about half that or so..
    I've had good luck with the ones from NAPA..never had one fail...

    If you do find a pressure problem, you can plug the return line temporarily to see if it's a pump or regulator problem but 99% of the time it's the fuel pump on these cars...I've rarely had a regulator go bad....but maybe you'll get lucky Micki, I'll cross my fingers for ya!
     
  7. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Thanks B&B we are going to tackle it this weekend. I would bet not having the fuel pressure regulator working for God Knows how long killed the pump. I noticed it as soon as I opened the hood.( Vacuum Line ) It does work, the RPM increases when you pull off the line.
     
  8. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    I'd agree with ya on that one Micki..:)
     
  9. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Update:
    It had good fuel pressure never dropped even hammered going up the road. The vacuum gage told the story. It was a clogged Cat. Runs like a top now !