Low Fuel pressure

[clintjohns]

I put a guage on my Holley fuel line. I have 1 lb of fuel pressure., and the little clear bowl fuel filter doesn't even fill up with gas when the car is running. What psi should a stock in tank fuel pump create. Surely more than 1 lb or fuel psi. Does anyone know if you can hook a holley blue or red pump up and run it using the stock setup and just remove the intake pump. Ya know mount the holley beside the tank and splice into the existing fuel line. Will it pull the fuel up and out of the tank??

[cjbiagi]

You should have around 4-5lbs with the stock in-tank pump. You could either have a bad pump, the screen sock inside the tank is clogged or a kinked restriction in the line. You can also try removing the gas cap just to make sure you don't have some sort of venting problem on the tank. You can probably add another pump inline but I don't think that is recommended. You'd have to pull fuel through the original pump and screen.

[clintjohns]

I took the fuel line loose and put it in a water bottle to catch the fuel. It filled it up in about 5 sec. So the pump is working. While driving the car you would never know it by performance wise. The only thing is when you stop it trys to stall a little. I guess my main question is, even if i have to drop the tank, can i remove the in tank pump, extend the fuel pickup to the spot it is with the intank pump, then install an external in-line fuel pump, without having to put a bung in the tank??

[cjbiagi]

I don't see why not. You want to remove the old pump and replace it with a extended pickup, right? Are you going to still try and put a strainer on the end? Of course you could also just install a new in tank pump. They seem adequate for most street setups.

[chevy art]

hey clintjohns a holley blue pump will pull that gas out of there with no problem. make sure you wire it up with a relay. electrics pull or push pretty good. mechanical pumps(stock types) push ok but dont pull so good.. zeke had that great post a few years ago when he altered his lines coming out of the tank b y using a 1/2 inch tube to get gas out and the old smaller one acted as a return or a vent. if you want to see that post, PM me and i will tell you exactly where to go on forum to see it, or i will send you a complete print-out of it from our site art. if you stay with the stock setup, then go by what CJ said as it was correct art

[clintjohns]

I would like to try a new intank pump to begin with, since it is easiest and prob. cheapest. I bought my last one from O'Rielly year and half ago. Anybody know of a good pump, and where to get it. So is it possible that the pump can be ok for free flowing fuel, but when it needs to create psi that it is crapping out?? My little pump dosen't have enough HP??

[Astre-mutt]

I would like to try a new intank pump to begin with, since it is easiest and prob. cheapest. I bought my last one from O'Rielly year and half ago. Anybody know of a good pump, and where to get it. So is it possible that the pump can be ok for free flowing fuel, but when it needs to create psi that it is crapping out?? My little pump dosen't have enough HP??

I had a low pressure problem in the Astre when I first got it. Turned out being the rubber coupling that fits between the fuel pump, and the fuel line in the tank. It gets soft with age.

[monza355]

So does everyone here agree that a stock in tank pump is enough to fuel a 355 with a 650 Speed Demon? I was under the impression that the stock pumps were not enough. I am having problems getting a good idle and also get backfires upon acceleration. I was told it is probably not enough fuel pressure. My pump is brand new. If I need a higher psi pump, what is a good one?

[clintjohns]

The pump i have in the car now is a cheaper one. Found a good bosch one for 110. Is a bosh pump that much better than a 40 dollar one at the local auto parts store

[cjbiagi]

If you are having trouble at idle I doubt it is the fuel pump. As long as the float bowl in the carb are full it will idle. Usually fuel pump problems are going to show up on the top end where it just can't keep up.

[clintjohns]

backfires could be a bad power valve in the carb. I had a problem with that, bought a new carb, and felt a big difference in performance right away. Now just got to get the psi up and I should be good.

[chevy art]

clint backfires in carb will make power valve go bad (rupture) and then cause very rich problem. backfires in engine are usually from opposite problem (lean out) - power valve opening too late or too lean of a primary jet. just some info i know of art

[Len]

There is one other poss that causes an intake back fire to much timing advance to soon.
Len

[Astre-mutt]

The pump i have in the car now is a cheaper one. Found a good bosch one for 110. Is a bosh pump that much better than a 40 dollar one at the local auto parts store

I think the Bosch pump your talking about is the one for the Cosworth EFI. Which is a high pressure pump.

[hammerdown7]

The high pressure Bosch-type pump for the Cosworth is outside the tank, it has a low pressure pump in the tank.

Dick