Adapt an OEM in tank pump?

jaybee · March 28, 2009, 04:54:23 PM

Has anyone adapted an OEM in-tank pump to an older tank, and would a factory pump for a GM 3.1L MPI engine be likely to be able to feed, say, 300-350hp?

UGLY OLDS · March 29, 2009, 11:20:46 AM

No idea's from ANYBODY :?:

I think many other guy's ,(Including ME), need some info on adapting an OE "Fuel Module Assmb " to an earlier tank...( Trust me ..Frame mounted pumps are NOT the "hot set-up" for FI systems ..Been There ..Done That ...Replaced 'em multiple times) ...

Bob....

enjenjo · March 29, 2009, 12:02:34 PM

I have done it, I was waiting for some one else to reply, I give too many answers now.

For an in tank pump, you usually need a sump to hold fuel near the pump when cornering. Not a big deal, 4" by 8" by 2" deep is plenty, and you don't want it sealed so the fuel can get in. All it's there for is to hold the fuel near the pump when cornering.

Probably the simplest way is to find a late model tank with a similar depth, cut the top out of it, and install it in the early tank, transfering the pump, and sump into the tank you are going to use. This works good on fat fender Fords.

I have also, in cases where the tank has an unusual shape, fabricated a ring that was soldered into the tank, that I could bolt a cover to with a gasket, that had the pump, and sump fastened to the cover. A deal similar to C9's fill neck on his fuel cell. Most factory sumps are plastic, you can make one from plastic storage containers with a few 1/2" holes drilled in it for fuel transfer. I have also made them from stainless steel, or even brass. Tanks Inc has one that can be copied. I attached a picture.

I have used an Airtex FP206 external pump with no problems. Airtex brand only, the look alike copies don't last. Walbro has a good one too. For any of them, you need a return line.

wayne petty · March 29, 2009, 12:31:39 PM

i should add in.. that instead of lead or lead free solder ... one might look at and try out silver solder to install the tank cuts out pieces...

most hardware stores have small amounts of low melting point silver solder with a tiny tube of flux.. and a few feet of the solder ... usually under 10 bucks... so much stronger... i used it to solder my friends (rip) eyeglass frames... plumbers use it to solder A/C tubing so it won't blow apart do to the higher pressures

oh... and look at some imported cars... like toyotas... they have bolt in fuel sending units (pumps and senders on one hanger) and the top of the tanks are usually depressed there for clearance ... so cutting out a piece around that tank unit would be easier to do....

jaybee · March 29, 2009, 04:47:51 PM

Thanks, good information. I'm about to start parting out Son's '91 Lumina and wondered if it'd be worth the trouble to drop the tank if the pump can't be made to work. Since it's FWD that limits the number of parts I can grab but so far I'm down for; fuel pump, rear seat bottom, probably the fuel door, steering column and firewall seal, heater-A/C assembly, electric radiator fans, hood latch, hood support struts, 4 decent roller tires & wheels, and aftermarket radio/cd player. I decided not to take the fuse block because aftermarket kits are such a good deal. I wouldn't imagine the radiator would be up to cooling a V8, otherwise I'd grab radiator and AC condensor. Can't think of much else that would do me any good. Windup windows, it's a bench seat car so no buckets or console, everything on the dash is ugly...maybe that's why they don't build them that way anymore.

wayne petty · March 29, 2009, 10:03:51 PM

stripping a lumina...

a 91.... there are people who need the motor and transmission.. if you have room to store it... the fuel injection wiring unplugs from the ecm and harness under the dash and pushes through the firewall hole... so it stays complete... ready to plug in...

radiator , cooling fans.. the power brake booster with master might work on something..

enjenjo · March 29, 2009, 10:13:05 PM

Steering column, and shaft, shift cable, throttle pedal, any mating electrical plugs are useful.

jaybee · March 30, 2009, 03:07:25 PM

Motor and trans are actually the problem. Transaxle has a problem in the torque converter lockup circuit, once locked it won't unlock until you shut off the key, so it's unplugged at the trans. The boy overheated it very badly and his friends helpfully filled the hot engine with cold water. I've tried head gasket repair in a bottle but no luck. I can get another one in just as poor condition for the cost of parts--less if it has a cracked head--so that's why it's going to the junkyard. Steering column is on my list & will add the matching shaft, hadn't thought about electrical connectors.

wayne petty · March 30, 2009, 08:39:42 PM

torque converter solenoids that will not release... or kick in when the trans warms up....

the torque converter clutch solenoids when they hang up really need to be changed... i usually swap in new pressure switches when i do it...
i have changed dozens of them.... in 125C's and in 440R4's

i have known several people that even after i fixed their cars... that they still did not trust them.... and one of these guys was a retired mechanic...