2000 Jimmy wont start

[ChrisGood]

Yesterday the mrs complained the jimmy wouldnt start up for her at the store, then suddenly it did. The way she explained it I thought low battery. Well this morning it does it again. I go out and it cranks over but wont start. I use some starting fluid and it starts, burns the fluid and dies. The fuel filter only has like 10k on it and it has a full tank of gas. Now since its in the garage I am thinking its not an issue with any water freezing up.

Next thing I think is fuel pump relay/fuse so I took one of the fuses under the hood for one of the other accessories (fog lights) and swapped it with the one for the pump, accessories work fine using the pump fuse so one would think the relay for the pump is good. I checked all of the fuses one by one under the hood and on the side of the dash. All are good. Any other ideas, ways to test the pump? In my VR-4 I can simply use my datalogging tool to cycle the pump on and I can hear it when it does. I think at this point it might be the fuel pump but first I want to know how to test it.

[MT-2500]

Can you hear fuel pump run 30 seconds on key on or run on engine crank?
Next test is single gray wire with a female end on it in fuel pimp prime connector in fuel pump relay area.
Check for 12 volts key on prime wire on 30 second key on prime.
Jumper it
Check EMC B fuse for power to orange wire to fuel pump relay.
Check gray wire from relay to fuel pump for 12 volts key on 30 second prime.
Also a 12 volt fused jumper on the fuel pump relay prime connector should run fuel pump.

[ChrisGood]

I have looked for the prime wire that I read about but have been unable to locate a wire as described. This is on a 2000 GMC Jimmy.

Please be more specific in the testing procedures as I dont work under the hood on this one very often.

I have not heard the fuel pump priming and I do have a fuel pressure tester in line and it shows no pressure. I would like to hot wire the pump so to speak to determine if its a clogged line/filter or a bad pump.

[MT-2500]

Originally Posted by ChrisGood

I have looked for the prime wire that I read about but have been unable to locate a wire as described. This is on a 2000 GMC Jimmy.

Please be more specific in the testing procedures as I dont work under the hood on this one very often.

I have not heard the fuel pump priming and I do have a fuel pressure tester in line and it shows no pressure. I would like to hot wire the pump so to speak to determine if its a clogged line/filter or a bad pump.

Check your PM for a wiring diagram.
When the key is first turned on or on engine cranking you should have 12 volts on the gray wire to fuel pump or at the fuel pump prime connection.
Get a 12 volt test light or a volt meter and check that first.
If no 12 volt power there check the orange wire for 12 volt power to relay.
Report back what you find.

[bhesson]

If it ends up being the pump, the site below sells the high quality Delphi pumps and they're much cheaper ...

http://store.getgmparts.com/fuel-pumps.html

[ChrisGood]

I believe it was ice in the line before the fuel filter. I took out the fuel filter and could easily blow through it. I used my fuel pressure gauges pressure bleed off to blow back through the line to the filter location. No blockage. I then decided to roll the jimmy to my work area and had to reconnect the battery to shift it to nuetral. When I went to turn the key to shift it I heard a spurt. Then I did it again and I heard a trickle. I still had the filter out and it blew out whatever was blocking the line. Put the filter back in and turned the key and immediately got 58psi on my gauge. Its running... Now to fix the 4wd. I started another thread and any help would be greatly appreciated.

[ChrisGood]

It drove fine for over a week and now the issue is back. Any ideas on this? I didnt replace the fuel filter last time, just blew it out and all the lines out. The filter doesnt even have 15k on it, could this be the problem? I mean the pump worked fine after taking the filter off and blowing it out.

[MT-2500]

Got spark?
Got fuel pressure?

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.
Or as much as you can get on it.

[ChrisGood]

Well this morning it started back up, its sold, gone, no longer ours.... Hope the dealership auction has fun with it.

[MT-2500]

Easy fix.
Good luck with your new one.
MT