1999 GMC Jimmy

KETIENNE

MEMBER
1999 GMC JIMMY
6 CYL
4WD
AUTOMATIC
174,000 MILES

I bought a 1999 jimmy. Will not start. Previous owner thought fuel pump was going out. But I can her pump engaging when I turn key on. Does anybody have any idea on what it could be? It turns over and about every 5or6th turn it sounds like it is firing.

7 Replies

WRENCHTECH

MECHANIC
20,761 POSTS

What is the fuel pressure?

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Monday, August 23rd, 2010 AT 3:16 PM

KETIENNE

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4 POSTS

48 when I turn key on. When I try to start it it is 20.

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Monday, August 23rd, 2010 AT 3:57 PM

WRENCHTECH

MECHANIC
20,761 POSTS

That's your problem. This engine won't even run if it gets under 55. It's a high pressure system and very sensitive to pressure.

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Monday, August 23rd, 2010 AT 4:27 PM

KETIENNE

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4 POSTS

So new fuel pump? Or could it be a filter problem?

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Monday, August 23rd, 2010 AT 5:06 PM

WRENCHTECH

MECHANIC
20,761 POSTS

The filter could have contributed to the fuel pump failure but won't be the direct cause of the issue. It should be changed automatically with the new pump to protect it. When they get restricted, they overwork the pump. The pump is strong enough to push through it but won't be for long.

Make sure you verify the contacts in the plug are good and tight too. They have a known problem with that.