fc_soldier

I have a LS2 swapped corvette thats been running for years. It recently starts and runs for 3-5 seconds and shuts off.

I changed the fuel filter/regulator.
I changed the fuel pump 255
I checked the fuel relay.
Im running hard lines to the regulator and a single braided line to the rails.

Fuel pressure reads 58 psi at the rails. Car will start run for 5 seconds fuel drops to 45psi and shuts off. When I go to restart the fuel pressure remains at 45psi, car won't start. After a minute I can reattempt... fuel will go to 58psi and start.

My thoughts:
Injector/injectors fail
Computer failing

Ideas?

C5 Diag

I’d do a voltage drop check on the positive and negative side of the fuel pump circuit…video below…how exactly did you check the relay ??

fc_soldier

I swapped with known good relay. Ill chdck the voltage in a sec

C5 Diag

You have to watch the video to understand how to do a voltage drop.

Kingtal0n

Errr vats?

Sounds like fuel pump is shutting off with impunity and injectors refuse to fire. If it was just the pump the pressure would drop while cranking because injectors pulsing would take some fuel out of the rail.

C5 Diag

Swapping the relay is not checking it !!…how do you know the wiring is good ??

fc_soldier

Well to defend that I'd say swapping a relay with a good is making sure there is a good relay. Yes wiring could be an issue. Wiring working for 15 years is hopefully last to my troubleshooting line. I won't dismiss because it was at my parents house for a while they have field mice and such. But I drove it 3 hours to my house in VA when it had this come up.

Kingtal0n

NO security light?
https://www.corvetteforum.com/forums...ty-system.html

https://www.corvetteforum.com/forums...ch-repair.html


If not vats you can always temporarily hard wire the fuel pump to stay on while cranking to determine if the ECU is involved