1995 GMC Jimmy cranks but wont start

Tiny
GRETSCH
  • MEMBER
  • 1995 GMC JIMMY
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 137,000 MILES
Engine got wet while flushing radiator. Was running when got wet and died. Started back up and ran for a few seconds then died for good. Motor cranks, wont start. Changed plug wires, distributor cap, and ignition coil. No change. Had ignition control module tested and was good. Starting to look like a fuel problem, but dont know how to test for it and dont know what the water would have done to fuel system.
Saturday, October 3rd, 2009 AT 5:38 PM

11 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
First, I agree with you unless water made its way into the intake. Regardless, here is the how to for checking fuel pressure.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

Are you getting spark to the engine? If not, check the cam and crank sensors for damage. You may want to scan the computer to determine if there is a code that is stored that will identify the problem.

One last thing, if you don't want to check for spark, try using starting fluid to see if it starts for a few seconds. If it does, you're getting spark. If it doesn't even try to start with starting fluid, chances are there is no spark.

Let me know what you find.
Joe
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Sunday, October 4th, 2009 AT 1:40 AM
Tiny
GRETSCH
  • MEMBER
  • 6 POSTS
Sprayed the starter fluid and it started right up, so definetly have narrowed the field to a fuel problem, but which one and how to tell? Since water on the engine started this problem, is it some sensor or relay that has shorted out?
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Sunday, October 4th, 2009 AT 12:31 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Good, now we narrowed it down at least a little. Next, I need you to do a fuel pressure test. I need to know if the pump is working. Here is a how to for checking:

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

If the pump isn't turning on and producing pressure, check the fuel pump relay in the power distribution box under the hood.

Let me know what you find.
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+2
Sunday, October 4th, 2009 AT 3:43 PM
Tiny
GRETSCH
  • MEMBER
  • 6 POSTS
I dont have a fuel pressure gauge and not sure if I can get one here on a Sunday, so here is what I did: Disconnected the fuel filter on the tank side and turned key on= good pressure. Then reconnected filter and disconnected on the engine side= still good pressure through the filter. This should rule out fuel pump and filter shouldnt it?
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Sunday, October 4th, 2009 AT 4:29 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It sounds that way, but the pressure could be lower than needed, or the regulator on the fuel rail may not be allowing pressure to build and allowing the fuel to be sent back to the fuel tank. Since we know it runs with starting fluid, either we have low fuel pressure, or a problem with the injectors. I hate to do this to you, but we need to check it.

If the pressure falls within specs, then we need to check for a power pulse to each injector to see if they are fireing.

Let me know, and sorry to be a pain, but the fuel pressure regulator could be causing the problem and we need to make sure the pressure builds at the rail.

Joe
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Sunday, October 4th, 2009 AT 10:01 PM
Tiny
GRETSCH
  • MEMBER
  • 6 POSTS
Came up with a fuel pressure gauge today. First test= Needle jumped to 5 when key turned on, then immediately fell back to 0. Each subsequent test doesnt even move the needle off 0. Also no fuel visible when connecting or disconnecting at the Schrader valve. Dry as a bone.
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Monday, October 5th, 2009 AT 8:12 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It sounds like a bad fuel pump. Can you hear it run? Also, check the fuel pump relay to make sure it's getting power and sending it.
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Monday, October 5th, 2009 AT 8:45 AM
Tiny
GRETSCH
  • MEMBER
  • 6 POSTS
I know that the fuel pump is running because I have disconnected the fuel line at the filter and turned on the key. Fuel pumps out steadily, but I dont know what the pressure is. I can also hear it running. Keep in mind that the engine got wet when this problem presented itself, so I am still trying to make this be an electrical problem.
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Monday, October 5th, 2009 AT 8:56 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It may be running, but be lower pressure than is needed. I just went through a similar situation with the same type of vehicle. It pumped, but was producing 5PSI. Not enough to run the engine.
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Monday, October 5th, 2009 AT 9:03 AM
Tiny
GRETSCH
  • MEMBER
  • 6 POSTS
Is there anything that could have gotten wet and suddenly caused the fuel pump to lose pressure? If so, will a scan reveal this, or would I just be wasting my money on a scanner?
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Monday, October 5th, 2009 AT 9:09 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Nothing that I can think of. The fuel pump relay may be bad, but it won't show up with a scanner.
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Monday, October 5th, 2009 AT 9:24 AM

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