Recurring '99 Silverado No Start........... . . ..

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by FergusonT, Dec 31, 2012.

  1. FergusonT

    FergusonT Rockstar 4 Years 100 Posts in the past couple weeks I have had some trouble with my '99 Silverado 5.3. I thought I had fixed it last wednesday. It has been running fine since then. Here's the history of the past couple weeks

    -Turns over but wont start. P0108 code, I replace MAP sensor, Still wont start

    -Fuel pressure around 52psi key on/engine off.

    -I replace the fuel filter, and get it running with starting fluid. Fuel pressure around the same when running. Idles but runs rough.

    -Clamp return fuel line and pull vac line off regulator to get 90psi. I replace fuel pressure regulator. Starts with starting fluid and when its warm, but no cold start

    -Replace fuel pump and get it to start cold, but runs rough. I get code for multiple misfires.

    -Replace all plugs and wires. Runs Great!

    And thats where I left off........until tonight

    Today I go to start it, its cold. I start it and notice a "chattering" noise coming from down by the fuel filter/fuel line. I drive for about 30 minutes then let it sit for about 8 hours. It gets cold, down in the 20's. I go to start it and I get the exact same thing that happened at the very beginning......Turns over, wont start, CEL Code for MAP sensor....UGH!!! So its stuck at my parents house, was there for a christmas gathering. Im in there the whole time telling my parents "Oh yeah I finally fixed the truck, running great now".....LOL

    Luckily they have a garage and its parked right in front of it. Depending on the responses I get from this thread, the first thing I plan to do is inspect every inch of fuel line that I can. I do recall the fuel filter was a bit difficult to remove, little bit rusted and I could have tweaked the line somewhere, but from what I inspected I did not see anything.

    What a fiasco.

    - - - Updated - - -

    What other sensors would cause this type of condition?
  2. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    Did you use AC Delco parts? Because if you didn't there may lay your answer. Another member [MENTION=12002]moogvo[/MENTION] was having trouble with his truck and after spending lots of money on parts he found the issue was caused by not using a AC Delco part making his other work a waste.
  3. j cat

    j cat Epic Member 5+ Years 1000 Posts

    he did use ac delco pump.
  4. FergusonT

    FergusonT Rockstar 4 Years 100 Posts

    yeap J is right, Ac Delco
  5. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    I'm talking about all the parts(Plugs, MAF, wires). Were they all AC Delco.
  6. j cat

    j cat Epic Member 5+ Years 1000 Posts

    the MAP 108 code is a high voltage error code. when the engine is idling you have a high vacuum this would create a voltage at the map of 1.2volts. when the engine is at WOT the vacuum drops then you get at the MAP about 4 volts. now since you have this error of high volts when it should be low with the engine just cranking this could be that the EGR is stuck open. this would cause poor/no start. I have never seen this error with this engine so far ...

    also the MAP has a seal at the install hole make sure thats sealed/seated properly no vacuum will give a high voltage error.
  7. FergusonT

    FergusonT Rockstar 4 Years 100 Posts

    Ok, I was thinking of pulling the map sensor so I guess I shud re seat it. I am a bit concerned about the chattering noise coming from the fuel line.
  8. j cat

    j cat Epic Member 5+ Years 1000 Posts

    If at the fuel filter you hear a noise the only thing that would do that is the fuel pump. that is the only device. the other item that could make a clicking sound would be the evap vent solenoid..this should not make a continuous sound.

    when you installed the fuel pump did you solder the new connectors in or the originals worked ? if you used crimps to splice in the fuel pump/evap sensor this could be the problem..
  9. FergusonT

    FergusonT Rockstar 4 Years 100 Posts

    Oh really, Yes I did use crimps....and actually I accidentally cut one in half so I just hand spliced it and used a ton of electrical tape.....So I should solder those connectors. I did not change anything on the evap sensor connector/wires. Just the pump wires/connector, swapped those out with the ones that came with the new pump.

    - - - Updated - - -

    also, this may be worth mentioning.

    I can't even get it to run with starting fluid. It will run but only until the fluid is burned up.

    And, yesterday the last time I drove the truck before it wouldnt start...I loaded it up with about 6 bags of 50lb dog food. And I was throwing them in the bed. I drove about 3 miles with it loaded up, and it sits now where I parked it after that. It drove fine the entire day.

    - - - Updated - - -

    I did not use AC Delco wires, fuel filter, map sensor, or pressure regulator
  10. j cat

    j cat Epic Member 5+ Years 1000 Posts

    so now you must buy some heat shrink wire insulation at radio shack. slide the heat shrink over the wire and solder those wires . then slide the heat shrink to cover the joint and using some heat make the tubing material seal these solder joints. the soldering iron will heat the material to shrink it.

    this is required because of corrosives will eat at these connections.. when sealed its forever.

    the pump is only 12volts but the current is high you must have a solid low resistance connection.....

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