Question for the 2nd gen gurus. I just tested the fuel pressures on my 86 N/A, and found them to be *higher* than the FSM calls for. The fuel pressure at idle with the regulator vacuum hose connected was 34 psi, and 42 psi with the regulator vacuum hose disconnected. The FSM calls for the numbers to be 28.4 psi, and 35.6 to 37 psi, respectively.

Both are about 6 psi over book.

Are these numbers within tolerance of what others are seeing 'in the field,' or do they indicate some kind of problem? If so, what problem?

 

Are you having a problem, or just checking fuel pressure randomly?

If there isn't a problem, then it's fine.


Or someone may have installed a higher output fuel pump... maybe.

 

The FSM spec is 28.4 psi at idle, but this will vary based on how much vacuum you're pulling. Idle speed changes it. Then for atmospheric pressure (vac line off), the specs are actually 34.1psi to 39.8 psi (page 4A-67).

I wouldn't worry about it. You're 2 psi over at atmospheric pressure, and the idle pressure will vary quite a bit due to circumstances I listed above. My own fuel pressure measurements are 34 psi at idle & 41 psi at Atm. Very similar to yours.

 

Ditto's with the above post. Actually mine, on the non turbo car, run 32-39 psi.

Just curious...do you have an aftermarket fuel pump? A Waldo?

 

In fact I have owned the car 12 yrs and have never opened up the fuel pump. I presume it is stock, but i have never really seen it.

I was checking the fuel pressure to diagnose a drivability problem, but that issue turned out to be something else (O2 sensor wiring).