82_4Door

I'm new to the forum, but I've pulled a lot of useful info from here in the past. Here's my problem. I've swapped a 93 5.0 HO motor in to an 82 Fox body (Fairmont). Engine is stock but completely rebuilt. For fuel, I've installed an inline fuel pump from Summit. I've mounted the pump and filter just outside the fuel tank, and I'm pushing the fuel through the stock 5/16 steel line. I've upgraded all of the rubber lines to high pressure lines. The pump seems to be struggling to keep up. The pump is rated at 43 gph (163 litres/hour), and 85 psi. This should be enough to keep up with the stock motor. Engine will idle fine, then I hear a squeal out of the pump, and the engine stalls. After hard acceleration, engine frequently stalls as well. I'm wondering if a later Fox fuel tank would swap in to the earlier Fox chassis? Or would a fuel pump/sending unit from a later FI model swap in to an earlier tank? The inline pump is really noisy, and I'd like to go to an in tank pump. The Fairmont shares most of the Chassis components with the Mustang, So tanks and components are easy to find at the local junk yard. Another option is an accumulator, with a second pump. What do you think?

threeg502

Are you running the required return line? An in tank setup should be the best along with the EFI style sender assembly.

82_4Door

I'm using the 1/4" stock return line. After looking at a lot of info online yesterday, I suspect that the MSD pump I purchased may have been slightly over rated. It's common for Summit to post "free flowing gph" and "max psi", but without a graph, there's no way to know for example what the flow is at 40psi. The pump was fairly inexpensive. I found a good price on a Walbro 255lph unit, so I ordered it. I'm going to do some pressure checks at the fuel rail just to be sure.

7upedition

I would recommend an intank walbro 255lph pump with an aeromotive inline AFR 30-70 psi, have you checked your pressure a stock motor should be 38-40psi fuel pressure. good luck

verne2

Greetings fromThailannd, Well I have another problem, For a couple of days every time I try to go WOT the engine bogs down, then the other day it just quit on me. When I turn the key I can hear the fuel pump whine, but the engine just turns over and wont crank. Any suggestions