I recently converted from TPI to carb and the intake pump started acting funny. It runs but surges and sounds like it wants to die. The fuel pressure also spikes really bad. I have a Holley Blue Pump (yes I know they don't last long on daily driven cars - its a weekend car only). I've read that you can just install it with the stock pump still in the tank and it will work but then I read you cannot do this. Has anyone done it? I don't want to drop the tank and pull out the stocker.

 

I am not too sure but don't you need a fuel pressure regulator to drop the PSI from 42 to 8, or does the Holley in-line do this for you?

You can also unplug the Relay for the intank pump and see if the inline one can get enough fuel through the intank one when it's not powered on.

 

I have a fuel pressure regulator that bumps the TPI stock 40'ishPSI down to 7PSI. The Holley Blue Pump is pre-set to like 19PSI.

 

So, how do you have the pumps and regulator lined up?
Are you feeding 40psi to the Holley and using the regulator after the holley?

Personally, I'd pull off the relay to the intank pump and see how the car performs, you might get enough fuel flow through it to satisfy the motor.

 

Do you have both pumps connected to the same electrical circuit? If so, you are pulling too many amps thru that circuit. If you are pulling too many amps, you can burn up the fuel pump relay. If both pumps are on the same circuit, then the voltage will drop on both pumps and can cause surging/fuel starvation. You need 2 relays, one for each pump. Also check the electrical connection&ground for both pumps. If you have a bad connection, the pump(s) can surge on and off. Just a couple ideas to check out.

 

I wouldn't run a dead pump in the tank. I've alway's contended that it's a major restriction when running a mech. or external pump.

I pulled mine out, and put a piece of fuel line in it's place.

If those impellers are not turning in the in-tank pump, it becomes a serious volume killer.

You might consider a mechanical pump, in stead of a inline electric pump.
I have a blue pump out in the garage hardly used, cause I wieghed the pros, and cons over a good mech pump.

I went with a Edelbrock Victor Series Pump. It's about 14PSI (yeap need a regulator) with 1/2 NPT.
I had to use a bottom feed plate for it to fit.

Good Luck,

Ron

 

Well I think I'm going to give it a try with the dead pump in the tank. Its going to suck if I have to pull the rear (once again) or cut a hole behind the seats to yank out the stock pump. I'm not even sure if I can run a mechanical pump. Isn't the spot welded shut on the newer blocks since my car was originally fuel injected?

 

I know 2nd gen 350(LT-1) don't have a prevision for a mech pump, but I thought all 1st gen 350 had them ?

Mine was a 82 CFI, and it just had a block off plate bolted on. In fact the fuel filter was bolted to it.

I can see why you don't want to drop the rear. It's a *itch. Been there twice, and I expect to do it again, when I drop in a fuel cell, run #8, etc...
FUNNN

Ron

 

Man, we dropped 2 rears today, my 86 rear and my brothers 96 rear. We put the LT1 rear with brakes on my car, took 6.5 hours to drop em and intall mine.

 

woooo, that's what I call a working day!
I think working on these cars for 1 hours = 4 hours of office work if not more !


Ron

 

It wasn't all that bad, it just started getting really cold. My bro's car was in the garage and mine was in the driveway.

 

I hear you on the COLD part, man It was in the 20's today.
Thankfully I have a 85,000BTU forced air heater in my garage, but if I had to work outside, I would ask tripple time from my car . That would include a 40 piece hot wings for the Daytona 500 on sunday !!!!


Oh Yea.....

Ron

 

I think If I have to pull out the intake pump I'm just going to cut a big hole behind my back seats then reweld it closed. I can pull out a rear in a camaro in about 2 hours taking my time ...I've done it many many many many times