HT4100 4.1, 4.5, 4.9 Discussion, Fuel Pressure in Cadillac Engine Discussion; So i have been dealing with a a problem of my 91 dev. stumbleing. so i did the egr the ...
- 12-19-09 06:26 PM #1Cadillac Owners Member
- Join Date
- Apr 2006
So i have been dealing with a a problem of my 91 dev. stumbleing. so i did the egr the cat and the o2 check the fuel pressure with key turned(42psi) running it is at about 38 when i give it gas it drops to about 32.BUT here isthe question if i leave the gage hooked up for about 15 min the pressure dropped to about 20psi(note the key is OFF NOT ON) is that a sign of a stuck injector inturn leaking fuel into the cylinder and causing the stumbling.. the stumbling goes away after a bit of driving...it is not throwing any codes at all no codes store either
- 12-19-09 11:59 PM #2
Re: Fuel Pressure
Either that or a leaky check valve and it's running back into the tank. You'll have to pull the fuel rail and turn the key on (DO NOT crank the engine) and look for a leaky injector.