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Discussion Starter #1
I'm having some problems with my 1994 Mark VIII, so I checked the fuel pressure tonight, and something doesn't seem right. All readings were at the rail.

Key on, engine off, it read 29 lbs.
Key on, engine off again, it read 39 lbs.
Car running at idle, 32 lbs.
Turn car off, 36 lbs.
Car running at idle, 32 lbs.
Turn car off, 36 lbs.

Does that sound like that is correct? When I reved the engine, the guage barely moved. Also, over the past two weeks, my mpg has droped from 18-19, to 13-14 over the past two tanks. When I ran the car at the track, it was down 7-8mph from where it should of been? The fuel pump is new.

Thomas
 

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Here's fuel pressure specs from my copy of the 1994 Service Manual. I've never done any fuel system work, except for repairing worn-through lines, so I can't help other than providing these specs.

 

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Discussion Starter #3 (Edited)
Thanks! Looks like it's in spec. A bit low, but in spec. That might have something to do with the tune. I guess I should post my problem and see if anyone has any thoughts:

Every once and while, while cruising down the intestate, 65mph-80mph, the car will stuter for a second, and then start loosing speed. Doesn't matter if you get back in the gas, it's slowing down. You pull off and it dies. Start it back up, runs super rough, dies. Do that three or four times, and then it will run perfectly, excellerate back up to speed, and be fine for a week or two. It has thrown the CEL a couple of times while doing this. So far all I have gotten is a lean condition in each bank. I did it today and I will check to see if I got anything different.

New Fuel Pump
Fuel filter 3 months old
Plugs 3 months old
Wires 1 year old
Coil packs 1 year old

I did a search and found a couple of guys that have had very similiar problems. The two solutions that I came up with were a faulty ECCT sensor or a bad PCM. I was wondering if you guys had any thoughts on the subject?

Thomas

**EDIT**
I went out and pulled the codes from today. Came up with the same 172 and 176 indicating a lean condition on each bank of cylinders. Also came up with a 452, Insuffecient input from VSS. Could that be a result of trying to restart the car while moving?
 
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