Several issues--!. code 54, I have ordered a fuel pump relay and will have that tomorrow. 2. Low pressure, guage says 37# and I read we should have 43.5#. 3. Car won't idle when warmed up.

In another thread Vader asks what pressure is after shutting motor off, thread ends. My pressure drops to zero instantly.

In another thread someone talks about testing a bad fuel pump vs fuel pressure regulator. Simple test not explained.

This is an 88 tune port that I blew 4 yrs ago. Now has 305 with flat top pistons, mild cam, 22# injectors, SLP headers, no cat, no air pump. Also has new fuel filter.

So how many things could go bad sitting for 4 years?

 

I would have changed the fuel filter first before I bought a pump - might just have a clogged filter - especially if it sat for 4 years. Did you use an additive before this "sitting" period? Gas turns to terpentine and eventually into sap if left untreated. If not, might have gummed up injectors, gummed up fpr, gummed up fuel lines, gummed up filter, etc.

 

If you did use an additive keep in mind that whatever "gunk" was in your fuel system ultimately gets flushed into the screens/filters of the fuel injectors

www.southbayfuelinjectors.com
516-432-6504

 

Still have pressure issue, now 35# with vaccum line plugged to regulator. needle now shakes or vibrates and drops closer to 30# with reving. Goes to zero pressure when motor is shut down.

New fuel pump relay has eliminated code 54 and now starts quicker. Prevously cranked until 40-50# oil pressure in system. Seems to idle better and doesn't kill, but idle still waffles from 800-1000-500 etc.

The fuel filter was the first thing I changed last week. No additives were used, only added ethyl w/o ethanol, approx 4 gals to almost empty tank.

Lo pressure issue: Should I change the fuel pump or the pressure regulator or something else first? And Why?

 

im having the same problem with my 87 350 tpi

 

I've replaced: Ecm, fuel pump relay, fuse (was blown), ignition switch, fuel pressure regulator, distributor shaft- pickup coil and module, fuel filter, and eventually fuel pump....nothing has worked!! The car doesn't even crank because of low fuel intake....When i turn the key to on position, I'm only getting 35lbs; as soon as the relay deactivates, the pressure goes to 0 right away! The car did crank initially after new pump, but only for about 30 minutes..it died when i hit 3000rpms, and ever since- nothing! Any clues as to why I'm losing pressure?

 

I just bought a new set of injectors from southbay for my 89 formula 5.7 and one of them was bad. Had similiar symptoms. Check your plugs, I found one of mine totally soaked with gas. I replaced that injector with one of my old ones that still worked (for the time being) and all is well. If it is an injector, then check your oil also. FYI, my stock fuel pressures are ~44 at prime and ~35 at idle.

 

Awesome advice I noticed one of my injectors was soaked and I think this might be my problem, does anyone know the stock size injector for a 87 350 tpi

 

22lb stock replacement....if you are going to replace your injectors go with a set of
22lb bosch lll's

 

How much would a set of thoughs cost? New or reman?

 

The set of 8 costs $165.99 plus you receive 10% off for being a tgo member
promo code tg11

 

How do I buy them I need those? Lol

 

you can either order them from our website or you can give us a call...we will be more than happy to help you.

 

Ok I put them in but now it won't idle and there's a popping coming from the motor.....what could I have done wrong?

 

Sounds like a lean condition, did you check for a vacuum leak?

 

what was wrong with the injector? Any time you or anyone else has a problem with our injectors please contact us so we can take care of it!


www.southbayfuelinjectors.com
516-492-6504

 

Back firing through the intake

 

First things first, you changed your injectors so verify your fuel pressure is normal at prime. See previous posts for numbers. If all good there, check and double check all ignition components. Did you ONLY change the injectors?

To the southbay guy, I did call and we've been playing phone tag. It will all work out, they seem to be good injectors, once I got past that they have "ford" on them. Thats a tough one for a gm guy.

 

My one bad injector caused a backfire in the intake also. May not be your issue, but I thought I would note it.

the problem with my new "bad" injector was that it is stuck open. Pressure dropped immediately when the pump went off. Spark plug for that cylinder was soaked with gas also. Because these were brand new, I checked them last. Should have checked it first before firing the car.