wesrams1

I am swapping a carbed 350 into my 1992 TBI camaro. I have heard that the fuel pump has too much PSI for a carburetor. Is this correct? Do i need to buy a fuel pressure regulator?

vetteoz

iTrader: (13)

I think the TBI pump is low enough for a carb; the TPI ones need a reg

wesrams1

cool thanx man

camaronewbie

WRONG! TBI pump is way too much for a carb - carb only takes 5-7psi, TBI pump makes 20+, and TPI pump makes 40+! You have to get a return-style fuel pressure regulator - there's no other way to use the intank pump. Most use the Mallory 4309 from Summit. There are other brands as well - but it HAS TO BE a return-style regulator which pushes the price to $80 - anything you see that is less is not a retrun style and will not work.

The regulator shown above will not work!

Gumby

Yep, the only $20 part that will work is a uni electric from like autozone that will be fine for a carb. Mount as close to tank as you can and below it.
Can find several post where folks had no problems getting fuel to flow through the pump in the tank off.

electric's push, why close and low, so gravity does most of the work getting the fuel out of the tank, then it pushes it.

camaronewbie

Most of the posts you see about folks pulling fuel through a non-operating in-tank pump are not good reference - because most all of them later end up replacing that pump - the in-tank pump creates too much obstruction and 9 times out of 10 any electric pump mounted outside of the tank will burn up shortly (within months).

Everyone wants to "buck the system" - Bite the bullet folks - if there was an easier way to do it with cheaper parts, there'd be a BIG sticky at the top of the carb forum about it - but there's only TWO ways to successfuly do this:

1) Drop the tank or cut up the trunk for the access hole, install a carb pickup in place of the intank pump, then either run a mechanical pump on the block, or run an electric pump outside the tank.

2) Use the intank pump and spend the $90 on the correct RETURN-STYLE fuel pressure regulator.

And lets face it - ALL these cars are either 1) way overdue for a new fuel pump, or 2) in need of a new fuel sending unit to get proper guage readings - so dropping the tank (or making access hole) is almost required by everyone anymore. Whether you install a new intank pump or a carb pickup is personal preference.

I dropped my tank, installed new sending unit and new intank pump and used the Mallory 4309 - that way my butt was (hopefully) covered for a few years - I have new equipment, and I can swap back to EFI at anytime (just in case I win the lottery and could actually get a shiny new crate motor)

I've been running it 3 years now with no issues at all - starts and runs everytime, always have perfect pressure.

Gumby

That would be the only $20 way out like the reg posted.

Though I dunno on the pulling through, every time I changed my fuel filter gas siphoned out of the tank at a fast pace as I scrambled to change it quick before getting soaked.

If there was allot of restriction in the intake pump it should not do that, should just dribble out. But it flows like water out a faucet via gravity siphon.

wesrams1

Well i just bought a 20 dollar fuel pressure reg (after reading the first response to my post), I guess it wont work.....Do you guys think it would be easier to just go with a lower PSI fuel pump?

Ca[maro]88

iTrader: (2)

dude drop your tank or cut an access hole, and get rid of the fuel pump part all you need is a tube that goes to the bottom of the tank, patch it up cut your return line keep your vent. go to the front of the engine, buy a 20 dollar mechanical fuel pump, bolt it on the side of your block, take your hard steel line coming from your fuel tank and put rubber fuel line going to your inlet on the fuel pump then take another piece of fuel line on the other nipple of the pump to your carb. put a fuel filter between the pump and the carb. go to oriellys part number 33033 is the filter. no need for an electric pump or anything like that. it cost 40 bucks all together for the fuel pump, the fuel line, and the filter. you can use regular black fuel line with no problem. theres only 3-8 psi and rubber line will never fail on you uinless it gets old and starts to dry crack. there you go, you got yourself the cheap way of doing it. i have a mech fuel pump on mine, NEVER had a problem with it.

chevymec

iTrader: (5)

I have been using a Jegs Billet non-return style regulator for a few years with no problem. I also use a TBI pump with my carb.

Gumby

Dead heading a TBI pump isn't that "bad" but I wouldn't do that with a FI one.

I got searious doubts about using my FI pump even with a return line for a carb. Its just over kill on fuel delivery that if it sprung a leak FIRE FIRE FIRE at 80+psi. or worse an reg failure that would dump about a good gal of fuel into the engine in a min, causing searious wash down.

Even a regular block pump can make an awful mess.
When my float stuck open I found the entire top of the engine swimming in gas.

chevymec

iTrader: (5)

Yeah, I know it isnt the best pratice to dead head the pump but I decided to try it anyways.

morepowerjoe

I know what your saying real well. I just changed my fuel filter on my 91 RS TBI. I couldn't get the fuel lines to thread back up right quick enough. So I had a gasoline shower. Wasn't fun at all.