Truck wont start

RAMCHARGER

MEMBER
1996 CHEVROLET SUBURBAN
V8
4WD
AUTOMATIC
107,000 MILES

How do I raise the fuel pressure? Already replaced fuel pump, fuel pump relay, fuel pressure regulator, fuel filter, oil pressure sending unit, upper intake gasket, csfi injector station gasket. Ran good for two days then quit. This was also my initial problem. Now fuel pressure down to 30. Need help desperately.

Tuesday, March 8th, 2011 AT 7:40 PM

3 Replies

CARADIODOC

MECHANIC
34,342 POSTS

Fuel pressure is set by the pressure regulator and is not adjustable by you. It will adjust while the engine is running from the vacuum hose attached to it. At lower intake manifold vacuum, the pressure will go up. If the engine quit running, check for spark first. If it is missing, don't worry about fuel pressure right now. If you have strong spark, bypass the fuel pump relay to see if pressure comes up and the engine starts.

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Tuesday, March 8th, 2011 AT 7:59 PM

RAMCHARGER

MEMBER
5 POSTS

Already tried the relay bypass with no luck. Engine still wont start and starting fluid wont work either. When it ran, it ran great. First I couldnt get my tranny to shift past 2nd, then it quit altogether again. Any help is appreciated. Thank you.

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Tuesday, March 8th, 2011 AT 9:50 PM

CARADIODOC

MECHANIC
34,342 POSTS

Ahhh. Have you checked for spark? If it is missing AND if the fuel pump isn't running, suspect the crankshaft position sensor or camshaft position sensor.

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Wednesday, March 9th, 2011 AT 2:55 AM