More 3300 troubles (FPR??)

[a1veedubber]

Hey all,
My wife has been driving the 91 this week....and now it is dead! On Monday, for a small amount of time, it seemed to cut out badly when trottle was applied. The problem persisted for about 5 minutes or so then went away completely & I was unable to replicate it. Then today, while she is driving it, she said that it started running very poorly then died. I try to start it now but it does not even attempt to fire.

I checked spark and it does have fine spark from all 3 coils. The fuel pump runs when the key is turned on.

One thing I noticed though...when my wife stopps cranking the engine, I can hear something run under the hood for about 10-15 seconds or so. It sounds almost like a VERY slow turning electric motor, and I can hear sound almost like air going thru the fuel rail. Then the electric motor sound & thew air rushing sound slowly die out. Its not the fuel pump either.....anyway I do not think it is. When the fuel pressure is relieved from the valve (where you would attach a pressure gauge) there is only a very small gurgle of fuel. My 86 2.5 has a much more powerful spray when the pressure is released! Could I have a fuel pressure issue??

Now I need to get the car home & into some light so I can really look at it!

ARGH!

[High Mileage]

What if you give it a blast of starting fluid? Will it run then? Is it possible you have a plugged fuel filter?

[a1veedubber]

I just got the car home (pushed with the Astro......it was 5 blocks away) and I can confirm that it runs perfectly on starting fluid......for about 5-10 seconds!. I am suspecting either a fuel filter or pressure regulator, as the pressure seems to be low or non-existent.

[High Mileage]

What if you run power to that test lead that powers up the pump? Will the pump stay running? My Century's pump would run for a few seconds,then slow to nothing.

The strainer might be clogged. Doubtful,but...?

It sounds like it is time to hook a pressure gauge to that shrader valve.

[a1veedubber]

Well, I just went and bought a pressure tester. One question though.....if the pressure is bad how do I tell if it is the regulator or the pump??

[High Mileage]

Test the pressure before the regulator with the reg out if the system to check the pump. ...such as disconnecting the pressure line,and checking it where you disconnected it.

Test the pressure before the regulator with the reg in the system to test the regulator. But you already knew that.

Did the tester come with different adapters to isolate things such as the pump?

As we know, it's much more practical to test/diagnose than to throw parts/labor at a problem only to have it remain.

There must be a way to unhook the fuel feed line at the engine,and start checking there. As I remember,that line is right there in front of the throttle body.

[razoredge]

I had this problem with a L27 (3800 TP) in a Regal. So long ago I cant remember the details but I just checked at the shrader valve and did nothing with the regulator, but then maybe I tried replaceing that first.

Then another odd thing that came to be and I mean odd, was my fuel lines were caked right full on the inside with rust scale and upon replaceing the fuel lines I cut them open and sure enough they had got all crusty on the inside. This is odd becasue it was a first owner car and was always driven everyday and was still on the road when I bought it, the lady had just bought a new Century (the last model). The car had 230,000 miles but was a incredibly clean otherwise rust free garage kept car. This has never happened to any of my other cars.

I had to take the fuel rails out and blow them out, they were chalk full, I had to take the injectors and spray them with kero with this siphon pressure "wand" hooked up to my air hose. Mechanics said I could never clean the injectors but it worked. I discovered this problem when I removed the regulator and a piece of rust flake rose to the top of the hole.

But both things happened. I had a pump running but at too low pressure and later this rust clog issue.

[a1veedubber]

Well, I checked the fuel pressure and it seems fine. It hovers right around 43-45 psi & drops to 41-42 psi when the fuel pump cuts out. The spark seems fine too, it seems as if the injectors are not firing for some reason. Time to go hunting for my FSM!!! Its for an 89, I cannot imagine there are too many differences!

[High Mileage]

The injector connectors can be checked for pulses with a test light.

[a1veedubber]

OK, I will be checking the injectors tonight after I find my test light.....Also, if the injectors have no pulse would that point me in the direction of the ECM? I am fairly certain that the injectors are not firing, usually I can hear them pulse when I listen to them with my stethoscope, but they are making no noise at all. The car will run fine on starting fluid.....

[Prospeeder]

Yes ECM! Or bad ECM ground, the injectors are always hot, but the computer switches the ground, if the ground is bad, then the injectors cannot fire