Cobra FPDM straight swap?

[xavier296]

My eaton conversion MM has been having some intermittent fuel delivery problems, and I believe it may be the stock FPDM dying due to the single GT pump. MM has 110k miles now. I have an extra 03 cobra one lying around, and thought I would try it. I found a few posts about colors into the FPDM, but no talk of actually using a stock 03 cobra unit. The 03 FPDM originally drove 2 pumps.

Any one done this or know if it works?

Symptoms of fuel delivery problem: Trying to die at idle, rough running till reaching 2k rpms. Fuel pump cycling strangely.

[burt ragio]

You need more fuel delivery. Add a K/B boost a pump run a larger ga. wire direct to pump from battary. Also upgrade to larger ga wire from alternator to battary. Remove the bend of oem fuel line at fuel filter along frame rail. Rubber hose has been know to colapse. Install larger fuel filter. See Muscle merc or other vendors on sight.

[mcgyver59]

You need more fuel delivery. Add a K/B boost a pump run a larger ga. wire direct to pump from battary. Also upgrade to larger ga wire from alternator to battary. Remove the bend of oem fuel line at fuel filter along frame rail. Rubber hose has been know to colapse. Install larger fuel filter. See Muscle merc or other vendors on sight.


Check he frps first, then for a damaged line in tank.

[SC Cheesehead]

You need more fuel delivery. Add a K/B boost a pump run a larger ga. wire direct to pump from battary. Also upgrade to larger ga wire from alternator to battary. Remove the bend of oem fuel line at fuel filter along frame rail. Rubber hose has been know to colapse. Install larger fuel filter. See Muscle merc or other vendors on sight.


^^^^ What he said. ^^^^

I'm running 11 lbs boost, 40+ lbs fuel pressure at all times under acceleration with the set up burt detailed (single GT fuel pump + BAP).

[xavier296]

I am not having any problems at full throttle, this is all idle type problems that have just surfaced. I have 15k miles of perfect service. When I dynoed, fuel pump duty cycle was fine at stock boost levels. I think my 110k mile FPDM is trying to give up the ghost, and want to try my cobra one since it is free, but need to know if it is a direct swap, or what I might need to change.

[FordNut]

It is a direct swap. The part number is different because the bracket is part of the FPDM assembly and the MM bracket is different.

Your problem is possibly due to the FRPS (this would be my first guess). Another possibility is the fuel lines inside the tank going to the pump. A third possibility is the fuel filter.

Lots of people seem to be having problems with the FRPS lately. I'm not sure why, I think it's in the tune. If it were strictly hardware related it would be seen by all of us. I have never blown a FRPS.

[xavier296]

Thanks for the info.

Drove the car 40 miles yesterday, cooler temps outside, and didn't have any problems at all.