Cmr0z28

on Tuesday, my friend and I installed my Racetronix 255lph pump. Everything was fine, after the install I primed the pump 3 times and it started right up. The next morning, the car turned over alot more than it usually does before it started. If it would sit for an hour or two, it would still start fine.

Now, if it sits for 1-2 hours, even if I prime the pump 2-3 times by putting the key in the "ON" position, it still takes 2 tries to get it started, and even then it barely fires up.


I also noticed that the car idles crappier and *kinda* feels like it's down on power. I ran at the track last night, and my trap speed was way low...

Any suggestions/input?

BlackScreaminMachine

Sounds like a tuning issue, if your FP was dying and you have hd the car tuned, and now your making the proper flow and pressure, then maybe your flooding the car... thats one possibility.

Another is maybe your fuel sock at the bottom of the bucket is clogged, or that **** got into the pump and killed it.

OR another one is maybe the tank didnt seal up right and your not getting the tank pressurized.

One thing I would do is get a fp pressure test on the car, run it under load, if FP is a constant 40 psi +/- 2 and then you should be fine on the fuel side.

Now its time to look at spark or tuning.

Injuneer

Check the fuel pressure before you do anything.....

It should prime to 41-47psi when you turn the key on, and hold above 40psi for an extended period after you turn the key off.

At idle, 41-47psi with the vacuum compensation line off the FPR. Put the vac line back on and pressure will drop proportional to intake manifold vacuum... maybe 6-8psi drop.

Tape gauge to windshield and take it out on the road, up to max load/high RPM and pressure should stay at 40psi or above.

Anything less that what's shown above and you have a fuel system problem.

DugRat

I had the same problem after installing the racetronix pump. After taking the pump out 3 or 4 times I found the teflon hose that came with the pump had several small holes in it, I replaced it with a piece of fuel injection hose from NAPA and problem gone. After e-mailing Racetronix I sent the defective hose back to them, they said they would reimburse me for the cost of the parts I bought and shipping, but I never heard a word back from them.

Cmr0z28

When I turn the key to the "ON" position, the pressure jumps to 50psi, then 2 seconds later, instantly drops to 20-25, then steadily decreases down to 0-5.

Idle/driving, pressure stays at 41psi. Hard throttle/WOT, it stays at 49psi until redline. I think it was 45psi at WOT with my stock pump...could this cause a loss of power? (rich condition)

Also, when I turn the key off, the pressure just drops down to zero.

BlackScreaminMachine

I see your issue, as you stated, turning the engine off should hold enough fp but its immmediately dropping off..... If that is the case the checkball/ valve is bad and the pump is bad.

Fred can correct me if I am wrong but that seems to be the issue, the pump. Did you use a new fuel filter sock off of the bucket??

This may have damaged the pump, if not something is not right from the beginning, i.e. defective.

Cmr0z28

I did not use a sock on the pump. There was a screen on it, and the sock they gave me wouldn't fit.

Cmr0z28

It's probably not the FPR....I took the vacuum line off and it wasn't wet.

Is the check valve in the pump itself or on the sending unit?

Racetronix

The diagnostic procedure laid out in the GM factory service manual should be used to properly diagnose this type of problem.

The sock we provide fits on the bottom of the bucket not the pump.
The pump fits inside the bucket.
http://www.racetronix.com/product/RX...LT1-FPKG-2.jpg
If the proper sock is not used debris can get into the pump and lodge itself on the checkvalve seat. The white 30 micron sock provided must be used. The bucket etc. should be cleaned and caution should be taken to avoid even the smallest piece of dirt from entering the pump during the installation process.