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TBI hard starting

Discussion in 'The Garage' started by COCHEV, Apr 5, 2004.

  1. COCHEV

    COCHEV 1/2 ton status

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    rig- 95 2500, 350, tbi

    cap and rotor are new, plugs look great, timing is on the money, took it to my buddy's shop and hooked it up to diagnotstics and everything checked out ok.

    in the mornings and after settin all day at work it cranks way longer than it should to start. after that it runs fine.

    i've searche around on here and 3rd gen and it seems that gm fuel pumps are kind of notorius for this kind of behavior, but i just don't want to throw parts at it. anyone else go through this?
     
  2. bablazer73

    bablazer73 1/2 ton status

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    Ck the tps voltage. If the TPS doesn't show proper voltage, It can be hard to start. If you just checked for codes, This won't show. You have to do a voltage sweep to see if it is working. Also a faulty temp sender will make it start hard. It might be telling the computer it's already warm!! That also won't show codes. The fuel pump is supposed to run for 5 sec after key is first turned on. Does It?? The computer controls that. otherwise the pump won't turn on until it see's a good crank signal.
     
  3. fortcollinsram

    fortcollinsram 1/2 ton status

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    Yeah like he said, the TPS and CTS can cause problems...I had a hard start problem on my K5 that was evading for a while. Turned out the fuel pump wasn't getting all 12V+. Once it started, it ran fine. Well Once I put my 454, the fact that the FP wasn't putting out its all was PAINFULLY evident. I hooked up a FP gauge and the pump was only putting out 9psi. Well I dropped the tank and as I was unplugging the FP connector, I noticed that the connector had fallen agains my exhaust and melted. This caused a severs voltage loss to the pump. Since I had the tank out, I replaced the FP and fixed the connector. So my advice to you is trust you first instinct and check the fuel pressure. I bet it is low /forums/images/graemlins/waytogo.gif
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Does the fuel pump run before you crank it?

    If not, I'd be looking at the fuel pump relay.

    Typical symptoms of that failure are hard to start, but after cranking longer than normal, it will. Thats because the oil pressure switch "takes over" and once it sees enough oil pressure, it will turn the fuel pump on.
     
  5. COCHEV

    COCHEV 1/2 ton status

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    the fuel pump does run when the key is on. i'm going to have to hook up a fuel press. gage. i'll check the CTS too. i'll post up when i figure it out. thanks for all the help. /forums/images/graemlins/thumb.gif
     
  6. 88Silverado

    88Silverado 1/2 ton status

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    When my fuel filter was getting plugged, my 88 bacame harder and harder to start. It also was loosing power. Changed the filter and everything fine.
     

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