01vetter

I have a '01 vette with stock fuel pump, Racetronics harness and a 40 amp KB BAP. My gauge is the SPA duel boost/fuel pressure unit.

On occasion my fuel pressure drops from a normal 61 psi to about 54 psi when cruising. It seems to be happening more frequently, to the point that I don't want to go into boost. I have the Innovate LC-1 with XD-16 A/F gauge and don't see any change in the A/F reading when it drops while cruising, but the cars computer could be compensating for the drop. My battery voltage remains in the normal range when the fuel pressure drops. Also, if I pull over and turn off the car and immediately restart it the fuel pressure returns to normal.

Since it is intermittent it is hard to diagnose because when I restart the car the fuel pressure returns to normal. Any suggestions what might be the cause?

Is this symptomatic of:

- Fuel pump going bad?
- Fuel pressure sending unit going bad?
- Racetronix harness relay going bad?

jbsblownc5

When I first put a supercharger on my 98 C5 MANY years ago, I needed an LPE pump and boost-a-pump to hold proper pressure with just shy of 500 RWHP. The first thing I would do is get rid of the stock pump, it's not designed for what you're asking of it...

Good luck!!

tail_lights

Sending a PM

5 Liter Eater

I had an Autometer EFPG that would read low when the sending unit got heat soaked.

01vetter

Thanks for the suggestion. My fuel pump with BAP seems to put out sufficient fuel pressure for my boost level (7 psi). My Tuner (Slowhawk) said that my setup was sufficient.

01vetter

Good suggestion. It does seem to happen when the engine is hot.

tail_lights

That's pretty much what my PM centered on. My SPA boost/vacuum sender appears to get this as well.