1999 GMC Suburban Dies while running, but starts rite back

ROCKYQUEST

MEMBER
1999 GMC SUBURBAN
V8
2WD
AUTOMATIC
179,000 MILES

Truck dies while running, doesn`t matter how long, may die after5 min. Or an hour, but starts rite back up Fuel pressure stays at 56 to 63, and stays high when vehicle dies. Haven`t found any loose or cut wires. I feel like I eliminated fuel pump relay. Whatta ya think?

5 Replies

RACEFAN966

MECHANIC
5,029 POSTS

Ok for me to be any help I must ask a few questions. Have you checked the cap and rotor? How old is the cap and rotor. This style of cap on GM vehicles are known for corrosion. How old are the spark plugs? When was the fuel filter replaced last? Get back to me with what you can and lets see if we can figure this out. Have you done a running fuel pressure test? Meaning did you do the fuel pressure test when you where driving to see what it does just as it dies?

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Tuesday, October 6th, 2009 AT 9:39 AM

ROCKYQUEST

MEMBER
4 POSTS

The spark plugs have about 13 to15 thousand miles, so I know there good, the cap and rotor maybe 30k, I probably need to change those to elliminate that, because this truck sits in the barn and is driven on the weekend a couple of times and corrosion could build. Another thing I realized is this happens in an idol state, in or out of gear. Yes, I have had the pressure guage on when it died and it didn`t drop fuel pressure. I pulled the f-pump relay out while running and guage was on and pressure of coarse did drop so I feel I elliminated relay and pump, do you agree? Oh, filter has been changed in last 10k.

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Friday, October 9th, 2009 AT 11:56 AM

RACEFAN966

MECHANIC
5,029 POSTS

Yes I would think that the fuel pump isn't the problem. Now these trucks do have a corrosion problem with the distributor cap. It is a disign flaw if you ask me. I have had these trucks towed to me dead and the cap and rotor was the problem they get like this green mossy stuff in them so yes check the cap. If there is any corrosion change it.

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Saturday, October 10th, 2009 AT 8:58 AM

SCOTTYMCDEE

MEMBER
11 POSTS

I had the same problem on my big block 93. If I left the cruise control button to the "on" position, (located on the turn signal arm) mine died the same way/symptoms. Turn off the cruise control button, no problems.

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Sunday, January 3rd, 2010 AT 1:00 PM

ROCKYQUEST

MEMBER
4 POSTS

Sorry, I now know where my kids get the habit of not coming around till I need something. I found the problem with the Suburban dying. Your diagnosis about the distibutor was not the solution but got me in the area, the plug on the coil wiring had a bad connection, I was able to simulate the problem by tweeking the coil wiring plug while it was idling and the plug pins would loose connection. I just resprung the pin terminals and it has not died since (knock on wood) Sorry it took so long to reply back. Like I said about not coming around til I need something, well it`s time for another question.