2000 GMC Jimmy won't start

  • 1 POST
  • 2000 GMC JIMMY

Engine Mechanical problem
2000 GMC Jimmy 6 cyl Two Wheel Drive Automatic 187000 miles

this Jimmy has had the computer exchanged out coz they thought that would fix it. But it won't start. First they said it was the fuel pump. We would get somewhere and it turns but won't start. Like it is out of gas. It has a tank full. Mechanic has tested the fuel pump it is good, replaced the computer, still does it. First it would do this, then finally start. They thought it was the starter or alternator, both checked out good. Been parked for a month now at the shop, they work on it in between jobs, checking out different things. My husband said it got hot him one time and mechanic wants to check something else out. Any ideas! Desperate

Do you
have the same problem?
Wednesday, October 6th, 2010 AT 8:59 AM

1 Reply

  • 21,076 POSTS

All I can do is tell you how to isolate the problem area.

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.

Was this
Wednesday, October 6th, 2010 AT 11:23 AM

Please login or register to post a reply.

Recommended Guides