Fuel Pressure quick test

[bratfry]

94 Bonny Se, I think I have a fuel pressure issue(rough idle). As a quick non meter test, how much fuel is released when you press the presssure release connection on the fuel rail, engine stopped. I get a tiny squirt and thats it.

On a good system, what has been someones experience. Wish I would have pushed it when it worked ok..

Thanks Gary

[LMP]

Was the EGR issue checked first? Rough idle is the classic symptom of EGR problem...
Tiny squirt is what is to be expected: there is no volume contained in a spring or air loaded chamber, and fuel by itself, like all liquids, does not change volume under pressure, so a tiny squirt later, all pressure is gone.

[bratfry]

The car has a very rough idle that shacks the engine and the exhaust has a spitting sound. New EGR, cleaned all spark plugs (they were pretty new), checked all plug wires for resistance and continuity (also new in last year), swapped a new ignition module for test, checked vacuum for leaks, tested each fuel injector by a disconnect and watched for a vacuum drop, all did except cylinder 2 (back,far left, looking from the front), replaced the injector, no change. That’s why I was wondering about the pressure, I just might change the pressure regulator anyhow, the car has 130,000 miles. I don’t mind changing things with that many miles. That’s about as far as I got.

Next up this weekend, new fuel filter, clean the throttle body, clean the idle air control, check the Mass air flow, and what ever else in the fuel spark systems. The car is driven only in the city on very short trips. No codes displayed.

[michael_k0]

i'm having kind of the same problem with my 95 ssei, no check engine light, but i am getting a p0172 code (too rich) and a p1670 (quad driver), I've cleaned all of the sensors with no luck. maybe the computer.

[bratfry]

Problem Solved....In my previous post I had a concern about the #2 cylinder. You could pull the injector and nothing changed, all the others had some kind of effect. Well a gear head friend of mine said, you found the problem area, now find the problem.

Well guess what, the spark plug wasn't sparking when I took it out, grounded the plug and turned the car on. Put in an old plug and the car runs fine.
I compared the plug resistance to other ones I had and it had similiar reading. So I smashed it with a hammer to make me feel good. No idea why it didn't spark.

By the way I did clean the throttle body, what a mess that was, but its clean now. I also tighened the intake manifold to stop a oil leak. What a great day in the garage.......