My 85 TA 305 TPI has a fuel pressure problem. I get an error code 44 intermittently after replacing the 02 sensor still.It runs fine on the highway,but when stopped at lights is when it idles down low,wants to stall,and the fuel pump sounds like its running irraticly (High pitch,then low,then high again). Thats when the engine light comes on.When I accelerate again it goes out eventually.It can run all week long without happening again.
Sooo..... I got a fuel pressure test guage,and heres what happens........
When I turn key to run without starting and prime the fuel pump,I only get about 9 psi till the pump stops,then she falls to zero in about 30 seconds.
If I start the car I can't get more than 37 PSI in park (ran about 10 minutes).
As soon as I shut it off,she drops like a rock to zero PSI.
If I Turn key to run without starting IMMEDIATELY after this drop,it jumps to 40 PSI,then drops to zero again.
I cant find any missing vaccum lines,no smell of gas or gas leaks either.
Is it my Fuel pump or pressure regulator? Injector leak?
Where do I start first???? Any help will be GREATLY appreciated!
THANKS.

 

sounds like a bad regulator . It should be holding psi for ALOT longer ( don't know exactely) than what it is now.

 

If it diesels when you shut the engine down hot then it would be leaking injectors. Otherwise it's most likely your regulator.

 

It doesn't diesel,so I guess Ill test regulator.
whats the best way to test it ? Thanks

 

See if there's gas in the vacuum line.
Also jumper the fuel pump test line, make sure you have a pressure gauge hooked up to the schrader, while the pump is running squeeze the fuel return line. Watch the pressure gauge. It should go up. Do NOT go over 60 psi. This test checks the fuel pump. By eliminating that it only leaves the injectors and regulator as a culprit.

 

Well, after monthts of procrastinating....I finally tested my retun line pressure. As soon as I pinched the line without even TOUCHING the key, I got about 12 PSI. When key turned,(about 20 seconds) I can feel the return line building pressure,and I got about 20 PSI. I didnt want to go any longer for fear of burning out pump.The pressuer held at 20 with the line pinched, and dropped when released.
Is it the pump not building pressure properly, or the regulator?

 

Don't worry about burning out the pump especially at only 20 psi. Remember, it runs the whole time you're driving.
Sounds like the regulator. Why'd you only get 20 psi? Were you only squeezing the return line a little bit? You should be able to get it much higher the tighter you squeeze it. Pliers work well for this.

 

I squeezed it by hand. I'm gonna do it again with pliers though. I was afraid of cutting the line actually, thats why I did it by hand. Maybe I will protect the line with a piece of rubber first, then clamp her down.
Ill post my results..... THANKS VIPRKLR.

 

Results:
Its GOTTA be the regulator.... I pinched the line AND put a vicegrip at the bend (with protection) on the line as shown in pic. 40-41 psi with key turned, and the same when running.The psi readings are different than before, so I assume its irratic cuz the regulator is ng.
If so, and im gonna repace the regulator, I wanna repace the plastic vaccum lines in the 2nd pic also. I have SLP runners (at least they look like em), so a gasket kit will be needed also. any opinions on the best set of gaskets to use?
Thanks, Guys.