Fuel pressure
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,682
Likes: 3
From: Coatesville PA
Fuel pressure
OK finally stopped putting it off as it seems my fuel pressure is def the culprit. My fuel filter, pump, and sending unit are all new, less the 5,000 miles but car is still acting up. So bought myself a fuel pressure gauge. What sort of pressure should it be reading just sitting. How about at idle? Thanks all in advance.
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,682
Likes: 3
From: Coatesville PA
strike 1
Ok, numbers are in for my 94. 42 psi sitting weather hot or cold, around 37-38psi while idling, and spikes from 40 to 35psi when revved. All those numbers seem pretty factory spec sadly. So what would be next on the check list? Idle is fine and going through the rpms is fine while cool. When it gets to around 150 degrees or more though it misfires under low rpm load or under heavy acceleration. Any ideas? My original guess was 02 sensors. Should they be next on my list?
Burning Brakes
Joined: Feb 2009
Posts: 785
Likes: 3
From: Richmond Virginia
Ok, numbers are in for my 94. 42 psi sitting weather hot or cold, around 37-38psi while idling, and spikes from 40 to 35psi when revved. All those numbers seem pretty factory spec sadly. So what would be next on the check list? Idle is fine and going through the rpms is fine while cool. When it gets to around 150 degrees or more though it misfires under low rpm load or under heavy acceleration. Any ideas? My original guess was 02 sensors. Should they be next on my list?
I need to learn to read LOL....How old are the plugs/wires/opti cap/rotor sometimes they are not noticeable untill closed loop and as you said that's also when the PCM starts looking at the O2 sensors.
Last edited by TWISTERUP; Aug 19, 2009 at 07:36 PM. Reason: ooops
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,682
Likes: 3
From: Coatesville PA
Currently have new wires, plugs, opti, and water pump with less then 20,000 and new fuel pump, filter and sending unit with less then 8,000 I'd say. Been progressively acting up starting about 10,000 miles ago. Just been kinda fiddling with options and trouble shooting since. So almost anything having to do with the engine and engine sensors short of the heads/block is pretty new other then fuel regulator(though my pressure is pretty much spot on). Only thing left i could think of is the 02s. Dunno.
Safety Car
Joined: Jan 2008
Posts: 3,939
Likes: 1
From: Vero Beach Florida
It could be an injector that is just not firing right or hanging up a little causing your hesitation. I’m not sure short of replacing them or having them checked out at a shop how you would know. Have you tried to check the resistance hot & cold you may find one that is out of spec which would cause this. You sound like you have replaced every thing else. The other thing is although your wires have been replaced you might have a bad one have you tested them.
