I am going from a TPI system to a carb setup in my 86 IROC. I am pondering what to do should i get a fuel pressure regulator or should i put a mechanical pump on it. Obviously the mechanical pump would be more reliable but i heard i have to drop the tank and run a hose in. BUt ive alos heard that you can pull the fuel through the old fuel pump and it may restrict just a little bit to the point were its not noticeable. The regulator idea seems easier but more costly but the mechanical pump idea seeems time consuming if i have to drop the tank or cut a hole in the trunk. WIll some body shine some lite on this crap so i can get my car done.

 

BUMP BUMP BUMP IM TRYING TO GET THIS DONE TODAY

 

I used my stock fuel pump in tank. mine was a tbi unit and was lower psi. you could use a fuel regulator and just bring the psi down. just make sure that your return line is sufficient enough to return all of the fuel. DO NOT dead-head regulate. buy a regulator with a return line in it.

 

I've been working on my car for 1 year (350 and TBI > carb), and just tuning for last 2 months Trust me - NOTHING gets done today! LOL

I don't know about the TPI in-tank pumps - they make way more pressure than the TBI pumps, and I know the Mallory 4309 regulator will only handle so much pressure. Actually, Mallory warns of destroying fuel pump when pressure restricted, more-so than destroying the regulator. And Mallory suggests it's a question of return line size rather than pressures really - a larger return line will allow more fuel to be returned easier, as more regulating means necessity to return greater amounts of fuel to the tank. How much of an expense and PITA would it be to install larger return line? I don't wanna know. Wait for input from someone that swapped to carb from TPI.

I don't know about the other return-style regulator available.

Might want to call Mallory tech support (216) 688 8300 ext5 and ask them.

I was TBI - and I chose to stay with the in-tank pump - my reasoning was 1) not having to drop the tank, which I've done since anyways, and 2) the noise of an aftermarket electric pump. I never really considered the mechanical pump option - not sure why - besides dropping the tank, it would have been simple enough, since I had a pump on my motor and used a block-off plate instead.

 

Well i got what weve code named "penelope" running last night as far as fuel i went with a mechanical pump and i pulled the fuse on my electric fuel pump worked good im going to eventually drop a tube in the tank though. Let me tell you Penelope was loud as hell today i will be running all wires exc were they should be radiator will be going back in and finishing touches will be made thanks for the feedback.