My dad recently ran into an issue with his 5.7 gas truck and I think the fuel pump is going. Due to the PITA factor on that, I would like to make sure it is going. I want to either install a permanent gauge or find an easy way to test the fuel pressure while running. What ever is easy and cheap.


Symptoms are low on power, poor idle at times, dies after start at times, no SES light, acts like it is running out of fuel. I could not remember if these would code with a high pulse width error or something. His is a 93 with the 8192K baud computer.

I installed a brass T with compression connectors on 2 sides and 1/4" male with a screw cap on 1 side in the input line in the engine bay of my grand am. i just put a gauge with adaptor on to test fuel press if needed.

So you cut the fuel line in half and just put a "T" in? It would be nice to have it in cab but honestly seems like too much work for a 30 sec test. maybe I will just mount one on the fuel line and call it good.. I would prefer to be able to go drive it in this condition to see if it falls off or not. IIRC, these trucks run between 5-10psi. Could probably make that TBI system more efficient just by adding high pressure to the injection system... Obviously would need smaller injectors and a new map though.

is there not a shrader valve test port on this engine??

I wish but I have never found one on these TBI motors. I have heard some of the BB models for commercial use had some extras but nothing on the 5.7. I have not studied the TBI too much though. There might be an extra port on it somewhere.

sometimes the motor is just tired. I tried everything on my 4.3 i had, rebuilt the TBI, cleaned the tank, blah blah blah....pulled it and stuck in a 400

The monte carlo GOES now!!!

anyhow, the tbi setup only has like 10-15 psi to it.

now its totally different on a vortec, if it has low pressure (under 55 psi) the injectors dont open and it wont start, dies, or acts like its missfiring. After 3 fuel pumps and droppin the tank we finally got a good new pump, of course the warranty only covers the part......nice.....

sometimes the motor is just tired. I tried everything on my 4.3 i had, rebuilt the TBI, cleaned the tank, blah blah blah....pulled it and stuck in a 400

The monte carlo GOES now!!!

anyhow, the tbi setup only has like 10-15 psi to it.

now its totally different on a vortec, if it has low pressure (under 55 psi) the injectors dont open and it wont start, dies, or acts like its missfiring. After 3 fuel pumps and droppin the tank we finally got a good new pump, of course the warranty only covers the part......nice.....



Engine is good to go. We have a tuning issue here.

So you cut the fuel line in half and just put a "T" in? It would be nice to have it in cab but honestly seems like too much work for a 30 sec test. maybe I will just mount one on the fuel line and call it good.. I would prefer to be able to go drive it in this condition to see if it falls off or not. IIRC, these trucks run between 5-10psi. Could probably make that TBI system more efficient just by adding high pressure to the injection system... Obviously would need smaller injectors and a new map though.Yea, just cut the line and put a T in. you can mount a ordinairy 30 psi pressure gauge right on it,or run a hose and gauge in the cab or tape it to the wiper. when done the test put a cap on the T. Simple, fast and cheap.

and as the title says...OT it shall go...actually it's going to other vehicles.

I hate autority with a passion