Car cranks fine, but will not start

PGIBSON6

MEMBER
1992 OLDSMOBILE 88
2WD
AUTOMATIC
165,000 MILES

My 1992 Olds Eighty-Eight was acting funny for a week or so. Whenever it was idling, it would not idle at a constant level. It would be idle low to high, low to high, low to high, fairly consistently. I got home from work tonight and popped the hood to take a look and it started really idling weird. When I got in the car and gave it some gas in neutral, it died. Now when I try to start it, it turns over and seems like its on the brink of catching and starting, but it never starts. Even when it's turning over and on the brink of starting and I give it a touch of gas, it won't start. Any suggestions?

1 Reply

WRENCHTECH

MECHANIC
20,761 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.

You may be able to shortcut a little on this one if you jump right to testing the fuel pressure.