Mechanics

ENGINE CRANKS OVER, BUT WON'T START

2001 GMC Jimmy

Engine Performance problem
2001 GMC Jimmy 6 cyl Four Wheel Drive Automatic 102000 miles

I have a 2001 GMC Jimmy,
I go to work in the morning and the truck started fine, like always, I never had problems starting this truck. But, today I come out of work, go to my truck and try to start it and it cranks, but won't start.
Dropped some fuel in the TBI and it fired up, but stalled after fuel burned off.
Fooled around checked conections, open air cleaner, about 30 to 45 min. Goes by, go try again, it starts. Shut it off and on a few times, no problems.
Go home, let it sit for an hour, try to start and again, cranks over nice, but wont start?
Any help would be appreciated. I read something about BCM or some security issues? Can that be a problem, or is it deeper than that. I hate to get rid of my Jimmy, since it's been good to me, till now : (
PLEASE HELP!
Avatar
Truckinhenry
December 21, 2009.




Welcome to the forum, when it refuses to start, use a gage and check fuel pressure. With the spider fuel system, the poppets may need to be cleaned.

JDL
Dec 22, 2009.
JDL,
thanks for your quick response. I will check that out tomorrow and let you know.
Also, I found that no fuel getting to the throttle body, and I don't hear fuel pump, but I don't ever remember hearing it before when the truck was running. Lol
What are poppets? And where are they located? Sorry for the novice question, never heard of them. I have work on vehicle for awhile, but never heard that.
I appreciate you helping me out, thanks
Henry
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Tiny
Truckinhenry
Dec 22, 2009.
When you first turn the key on, no crank, the pump should run for a few seconds, listen then.


http://www.2carpros.com/forum/automotive_pictures/170934_spider_fuel_system_1.jpg


JDL
Dec 23, 2009.
Ok JDL,
I checked for fuel pressure through the stem valve on the line comeing to the engine, near firewall. That was the only valve I could find with a valve stem and a black cap. My gauge reads " 0 " big goose egg.
So, I listened for fuel pump and I didn't hear it. Now, is the pump bad or something else I need to check? And is the pump in the gas tank or is it external?
Thanks again for your help.
Henry

Tiny
Truckinhenry
Dec 23, 2009.
I'd have to check for voltage and ground at the pump connector, engine cranking. The gray wire is voltage to the pump motor, the black wire is ground. If no voltage, I'd have to check the circuits at the fuel pump relay. The pump should be in the tank.

JDL
Dec 23, 2009.
JDL,
is the fuel relay under the hood in the fuse box?
And what else do I look for?
Thanks again,
henry

Tiny
Truckinhenry
Dec 24, 2009.
Yes, it should be in the fuse box under the hood. Also, check the ecm b fuse circuit for voltage. Should be hot all the time.


http://www.2carpros.com/forum/automotive_pictures/170934_jimmy_fuel_pump_relay_1.jpg


JDL
Dec 24, 2009.

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