Electric fuel pump for 6.2

[evo rider]

Is it possible on a 6.2l to use an electric fuel pump in replacement of the mechanical lift pump, so the lift pump is completely bypassed altogether?

[CooCooKachoo]

Yes it is possible.

You can remove it and purchase a lift pump block off plate for a small block chevy or just loop a piece of fuel line from the input to the output and leave it there as a backup.

[DmaxMaverick]

I don't recommend leaving the mechanical pump in place if you switch to electric. When the mechanical pump fails, it stops pumping fuel and the engine either doesn't run, or runs poorly. That's your indicator the pump has failed. If you aren't using it to pump fuel, you'll have no such indicator, and when it fails, it will continue to self destruct, possibly dumping metal into the crankcase, and/or oil out of the pump, until you get another indicator.

If you switch to an electric, you'll need to also install an engine-stop failsafe. Usually, this is an oil pressure switch, like the 6.5L has, to send power to the pump only when there is oil pressure present. With this, the pump will stop pumping when oil pressure goes away, like in a crash (rather than pumping fuel all over the crash scene). You can also wire in a momentary power switch for priming, pre-run, etc.

[HH]

You can use one from a early 90s CK pickup, but you will need to install some kind of fail safe as indicated above. I agree with the above, get the block off plate. I did this on my Jeep ZJ diesel conversion.

[john8662]

IMHO keep the mechanical pump, but avoid aftermarket lift pumps, I've had them fail in very short order (especially Carter pumps).

Get the OEM AC-Delco pump and forget it.

I like the idea of an electric lift pump installed before the mechanical lift pump but only used for priming the fuel system (which can be a PITA on 82-83 trucks with big primary fuel filter).

J

[evo rider]

when using an electric fuel pump, do I need to consider the amount of pressure it will put out?, I wouldnt want to possibly damage the IP with too much pressure.

[DmaxMaverick]

Fuel pressure should be 4-10 PSI. More won't damage the pump, but can cause leaks and running issues.

[80Sierra]

I am running a stock TBI fuel pump for my turbocharged 6.2L. It has approx 15 PSI of pressure applied to the injection pump, but I haven't had any problems with leaks (less a return line on an injector behind the turbo, of course!). The pump is designed for gasoline, but the fuels are so similar in viscosity that I am not concerned about it failing.

As far as the fail safe goes, stock TBI vehicles have two forms of supplying power to the fuel pump, one is an oil pressure switch, and the other is a ECM controlled relay that is wired in parallel with the oil pressure switch. The oil pressure switch is supposed to behave as a backup to the relay, and closes once it sees approx 5 psi of oil pressure. The ECM controls the relay by powering it's solenoid for 2 seconds every time that the ignition module senses the ignition coil fire.

Since my diesel has a marked lack of an ignition coil, I simply used the 5 psi oil pressure switch as a permissive instead of a backup. If my engine shuts down, so does the pump. The pump has a built in check valve that keeps most of the fuel pressure for several days at a time, but the system re-pressurizes so fast after the thing starts, you hardly even notice that the pump wasn't pre-primed.