hedhntr

Hello all, I'm new to the site. Just purchased a 1992 RS that was a TPI car but the previous owner switched it to a carb car. He never drove car after switching over. It sat for a year until I bought it yesterday.

The fuel pump has not been changed to my knowledge. They installed a cheap fuel regulator near carb. Fuel pump comes on for a few seconds when ignition is turned on then stops. It's enough to fill the carb bowls. Motor runs for under a minute then dies. Checked carb and bowls are dry. Pump does not run after initial few seconds at first ignition. Is there a wire from the old TPI harness that tells the fuel pump when to turn on and stay running to keep pressure or do I need to switch pumps? Is it possible to mount electric pump on front wheel well and draw fuel thru the tank pump if the tank pump is not running?

Any help is greatly appriciated..

jwfirebird

iTrader: (2)

The pump used to run the pump after the engine starts. You can rewire it so the oil switch runs the relay but sounds like you have a bad one because it should run on the ops circuit once it starts from the gas in the bowl. Go on Austin third generation there are diagrams, you need to see what is wrong with your sensor and disconnect the output and run it to the coil side of the pump relay. The reason they fail is because the pump draws a lot of current and it all goes through the ops and it's not designed for that

dixie wrecked

iTrader: (6)

Depending on how you want your car setup and such, you could just wire it up to a manual switch. Run 12v to the pump and control it manually.
Whatever you do, dont mount an electric in the engine bay. It will overheat a few miles down the road and quit working. Ask me how I know..

jwfirebird

iTrader: (2)

if you put it on a switch and have a wreck its just going to keep pumping. if you wire it to have the ops control the relay it will shut off and you dont have to sorry about it

dixie wrecked

iTrader: (6)

This is true, its a risk you'll be adding, unless you add an interia switch. Those will allow current through until you're in a collision or hard bump and it cuts the circuit. I know crown vics have em, and it baffled the hell out of me till I realized they had em lol.

jwfirebird

iTrader: (2)

fords have all sorts of unnecessary stuff to go wrong. the ops is already there and easy to troubleshoot

five7kid

iTrader: (14)

Welcome aboard thirdgen.org.

Not to nitpick, but RS's were TBI, not TPI. Not that that makes a lot of difference, but it could make some.

The oil pressure switch (OPS) was used as a back-up circuit to keep the fuel pump running in 3rd gens - it wasn't an "accident safety switch". It's really hard to say what someone may have done when switching from EFI to carb, but fussing with the OPS is not likely. Since the fuel pump comes on when the ignition switch is turned on, that indicates the ECM is doing the right thing for engine start, but the run circuit is not. The OPS is part of the run circuit.

Oh, and one of the first things you should do is get a return-type fuel pressure regulator in there. In-tank pumps don't like to be dead-headed.

mrzlgzag

Fi nd a key source of power I used my windshield wiper power run that to your fuel relay.... It's by the brake booster up on the firewall......... It was a tpi,tbi or whatever and you removed it your fuel pump will only run for two second then shut off..... As far as a expensive return regulated it's not necessary... What I did and it works perfectly in then return I installed a T usually used with a fuel pressure gauge, removed the fuel pressure gauge installed a bolt and disk on your pressure with that... Tighter the bolt the more pursue loser the bolt less pressure.... Works perfectly pretty cheap

Street Lethal

iTrader: (16)

I am assuming he swapped to a distributor w/vacuum canister, that is why. If the ECM does not see RPM, then fuel supply is cut off because it assumes the engine isn't running. As pointed out, find a key-on source in the fuse panel and wire it in, be sure to wire in an inline fuse in between the pump and fuse panel wire...

five7kid

iTrader: (14)

Maybe it's just me. Anybody understand this?

makaveli09

I don't get it??