Question about 1988 Chevrolet Suburban

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I have an 1988 suburban 4x4 with 5.7 TBI V8. I have had to rplace the 2 injectors 2 times in the last month. I have replaced all the ground straps and cables and now I don't have fuel coming out of the injector and I don't have any spark. After replaceing the grounds it started and ran for about 10 minutes then died and I have not been able to start it since

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  • 834 Answers

It would seem like a problem with the ECU or the fuel pump, but the common link between those two systems is the ignition module that is located on the distributor under the distributor cap, and that module is actually responsible for the fuel pump signal to run the fuel pump, the dwell signal to cause the ignition coil to fire, and also the signal that the ECU uses to time and fire the injectors, and you can remove the ignition module and have it tested for free at most auto parts stores.

Before you replace the ignition module back into the distributor, be sure to clean the mounting surface for the ignition module, and be very certain that you do use the silicone grease or die-electric compound (which ever one came with the module) to completely cover the metal mounting surface of the ignition module with that grease/compound because it is a heat sink and the ignition module will burn out in no time if you fail to use the heat sink grease/compound.

Posted on Jun 02, 2010

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  • Zaraki Jun 02, 2010

    Also; Check the power wire to the ignition coil, and with the key in the run position there should be full battery voltage going into the ignition coil and running over to the ignition module inside of the distributor, and a loss of full battery voltage to the ignition module from the ignition coil would mean that the ignition coil is shorted out, and it is not un-common for the ignition coil to damage the ignition module. However if there is full battery voltage going through the ignition coil to the ignition module, then the ignition module only will need to be replaced.

  • dan_smith960 Jun 02, 2010

    Thank you, I will check these things but I forgot to mention that I have full fuel pressure at the injectors.

  • dan_smith960 Jun 02, 2010

    Thank you, I will check these things but I forgot to mention that I have full fuel pressure at the injectors.

  • dan_smith960 Jun 02, 2010

    Thank you, I will check these things but I forgot to mention that I have full fuel pressure at the injectors.

  • dan_smith960 Jun 02, 2010

    Thank you, I will check these things but I forgot to mention that I have full fuel pressure at the injectors.

  • dan_smith960 Jun 02, 2010

    Thank you, I will check these things but I forgot to mention that I have full fuel pressure at the injectors.

  • Zaraki Jun 02, 2010

    Even with full fuel pressure in the fuel system I would still suspect the ignition module or coil to be the problem.

  • dan_smith960 Sep 14, 2010

    Your suggestion was helpful. I replaced the module in the distributer and have not had a problem since! Thank You

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The PCM (ECU does that) its part of what is called EFI, electronic fuel injection, it's a computer, that gets inputs, and uses those inputs to injector perfectly at ALL times.
what engine? 3cy. or 4? is it TBI injected or MPI injected
1 injector or 4? we need to know that first.
does it run on test fuel for 3 seconds.
when was last time it run perfect, last week last year. what?
first off stop guessing, you can go broke that way.
want to diagnosis it? the steps are easy. if fuel is good..
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  5. if not, why wait?
  6. 6: is spark good tall cylinders not just 1? is the timing way off if yes, the cam belt did slip, do not fiddle tiiming, fix the belt. first.
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I think all 94 metors are TBI engines, one injector
up to 1997 inclusive.
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have you learned how to use flash codes (DTC) yet?
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the TBI allows the mech to watch injection, at the TB.
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does it?
the ECU brain cuts fuel at the first sign of:
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1988 5.7 TBI Nightmare This is the start of what the problem was and is, I had a RV cam installed when the engine was rebuilt a year ago. the cam was not a computer friendly cam so after a round with the rebuilder and discovering the specs weren't the correct ones for the cam I installed a 3702 edelbrock cam and lifters with a 7800 timing chain and gear set after I had tried two chips from Jet and no improved performance and the 3rd chip was to be for the cam and that is what is in the ECU now and I have tried about 5 different BCC chips and the bottom line is the power is there but something is happening its hit and miss the idle will sometimes lope, is stalled when first started and acts as if its starving for fuel or its bogged with to much fuel. the fuel pressure is 10 - 13 psi and I have R/R the TPS, IAC, ESC and knocks device , EGR and Solenoid, MAP, Temp sensor, and the Dist is a Procomp 10001 with a MSD-5526 coil. the Throttle Body was rebuild and the ECM was replaced with a Rebuilt ECM. it will smell rich etc. but with the things that goes on it does not show any codes?? I have no clue just feel stupid this is been a simple thing that is kicking my **** and now its a challenge but still loosing the fight too far in and too much spent to stop,. LOL Help !!!! The BCC is a california vehicle AFBX, 5.7TBI TH400 A/T P.S. the key can be turned of and back on as the engine not dying and seems to correct the power and run problems but will not last goes back to running bad or with problems. ?

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