1988 Chevy Truck Truck will not start. Almost but no

MENTALISSUES40

MEMBER
1988 CHEVROLET TRUCK
V8
4WD
AUTOMATIC
240,000 MILES

I have a chevy scotsdale 1988 4x4 with a 5.7L 350, I noticed coming home from work that the truck had a miss, couple days later it stopped altogether, I figured it just needed a tune up, so I put plugs, wires, rotor button, and cap, and the wires are all put on corectly, when tried to start it really acts like it wants to run but just wont, thick white smoke comes from the throttle body, and exhaust.I figured I might of had a bad ignition module, so I replaced it. Still wants to start but just wont, it almost seems to me that it is getting to much gas.I am kinda at a loss at this point. And anyone with a possible solution. Pls. Let me know. Plus I change the fuel filter as well. Thanks Steve

1 Reply

WRENCHTECH

MECHANIC
20,757 POSTS

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.