Automatic fuel pump?

[andrewrenow]

Has anybody tried this in their t4wd? When i needed one they had these available at autozone for $20 more than the one i got. I was skeptical about it because our cars didnt come with this out of the factory. Are there any benefits from this?

[ARCHINSTL]

Presumably this is it - $15 more?:
http://www.autozone.com/autozone/parts/ ... 73884_4967_
Tom M.

[Petros]

are you talking about an electric fuel pump? This was a popular "performance" mod back in the days of carburetors, supposedly reduced the power drain on the engine to use an electric pump, and it could deliver more fuel if you had a highly modified engine. Two problems, with a mechanical fuel pump if you are in a crash, when the engine stops, so does the fuel delivery (that is why in some racing classes only mechanical pumps are allowed). And you have to make sure the replacement pump delivers the same pressure as the factory pump or you could overpower the float valve in the carb and it will flood the engine. As for the claim it has less drag that seems unlikely to me since you have to pull electrical power from alternator to drive the pump rather than mechanical power from the cam shaft, you are pumping the same amount of fuel either way, and not likely the pumping efficiency is noticeably different between the two pumps. It does have the advantage of cleaning up the engine compartment, it is more common to install the electric pump back near the fuel tank.

When I was young my dad had a Lancia Appia (used an unusual all aluminum V-4 engine), when the fuel pump went bad the local repair shop installed a generic electric fuel pump (says it cost less than getting a factory pump from Italy). After that the little car made a "tuck,tuck,tuck,tuck..." noise from the trunk area when we drove around in it. We all thought it was funny.

[danzo]

Does your car still have the factory carb? Even with an aftermarket carb you will need a FP regulator with an electric pump. Years ago I put an electric pump on my old Triumph that still had the original mech one (which incredibly still worked). The car had the 32/36 weber when I got it, but I later switched back to the stock Stromberg for autocross rule reasons. It ran fine with either pump/carb. I kept the mech pump mounted to the engine as backup for the electric.

In short - you won't notice any change with an electric pump/regulator. If you do get one you might want to mount it underhood for easy access.

[rer233]

i think electric pumps are designed to push rather than suck--- should be mounted as close to the tank as possible.

[danzo]

That may be more true for higher pressure FI pumps. I had a pump from a carb'ed Ford Ranger IIRC mounted near my stock mech one. The hoses were the right length so I could get the mech pump hooked up in 2 minutes if I needed it. I just didn't want to be stuck on the side a highway fishing for tough to reach fuel lines under the car. But in 5 years of driving the sucker pump worked fine.

Andrew did you ever get an electric pump?

[ARCHINSTL]

Millions of Morris Minors (and tens of thousands of Singers and MG T-Series cars) had their SU electric pumps mounted on the firewall - and worked well. I can't comment on other BritMobiles, though. MG (and others?) went to rear-mounted, external, pumps to eliminate vapor lock which occasionally occurred on the assorted T-Series. However, vapor lock was never a prob with my many Minors - or the Singer, for that matter.

My impression that modern cars have pumps mounted inside the tank is for cooling of the pump - although I am unsure of this.
Tom M.