1999 GMC Jimmy Very Hard to Start

TARENDS

MEMBER
1999 GMC JIMMY
4.3L
V6
4WD
AUTOMATIC
150,000 MILES

Truck is very hard to start. When I do get it started is runs just fine. Thought it might be fuel pump. Jumped pump at relay and I hear it running but still will not start. I thought it might be spark, but when it does get started there are no signs that the spark is bad (not missing). I'm at a loss on what to check next.

5 Replies

CATAFINA

MECHANIC
168 POSTS

Check the fuel pressure if its 60-66 psi, start here

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Saturday, November 28th, 2015 AT 10:08 PM

CAR-MAN145

MECHANIC
321 POSTS

These motors need 60psi of fuel pressure to start and when a fuel pump gets week it will not start or take a long time to start. Once you get it started it will run fine you probly need a new fuel pump even knows it runs when you jump it.

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Sunday, November 29th, 2015 AT 1:37 AM

TARENDS

MEMBER
3 POSTS

I hope the fuel pressure tester up and when I turn the key it jumped up to 60 PSI. When I try to start it the PSI drops down to 50 to 55 psi. When I get it started The PSI bounces very rapidly back-and-forth between 50 and 53 PSI.

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Sunday, November 29th, 2015 AT 11:03 AM

TARENDS

MEMBER
3 POSTS

If the fuel pump was bad or going out would I would I not have issues when I'm idling or driving should not have some stuttering or missing if the fuel pump is going out?

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Sunday, November 29th, 2015 AT 11:05 AM

CAR-MAN145

MECHANIC
321 POSTS

No this is pressure it needs to start it is a bad fuel pump in my thoughts if it as 60 psi when to turn the key on then the pumpp is working but with out cranking the motor over it has to have 60 psi to start key on engine off