302 EFI conversion

[broncomania]

What does the mustang run? I know they only used one in tank pump right?

I will see if I can get some wiring diagrams before this weekend.

only one in the tank pump.

[chuzie]

the mustangs began to swap over from SD to MAF in '88 and from '89 on they were MAF. Looks like you will need the Bp sensor, MAF sensor, and computer to match.


The difference between these two is whether or not a vac line is connected to it or not.
This is a MAP sensor


This is a Bp sensor

[broncomania]

chuck im searching for you some more parts.

[chuzie]

Just pondering here...

My rig used the F-250 HP pump and accumulator. Judging by the size of that accumulator I was wondering if it is possible to use 1 or 2 of those large, in-line, fuel filters (the round can type about 4 or 5" diameter) between the LP and HP pump as an accumulator. They would certainly hold enough fuel. Just don't know if they would cause too much drag on the flow for the HP to stay primed.

[chuzie]

Status on parts?

[broncomatt]

Chuck, got all the diagrams. I guess I'll try and scan them and send them to you.
Any other info you need?

[Bighorn]

[quote=blazinchuck]

Im worried about that. I just find it hard to believe i need to run 2 pumps...what about a holley blue or black...surely that can work by itself???
QUOTE]

Don't be scared of the two pumps. It's not a "need" but a "purpose built system"

A single HP pump will work but you must keep the pickup submerged in the fuel cell all the time. This is easy to do with a full tank. But if you run it low, get off camber and the pickup sucks air, engine will stall. That's the problem you said you had with the Toyota. That is the why you need the accumulator for what you are building. Even if you suck some air out of the tank, the accumulator has enough gas to keep the engine running long enough to get back to normal. OEM EFI fuel tanks and tanks the Bronco vendors sell are baffled and mount the fuel pump in the lowest point of the tank minimizing the effect of fuel sloshing around. But even those tanks were not built or designed to be doing what you building.

The low pressure feeding directly into a high pressure pump without the use of an accumulator in between is just a waste of hose clamps.

For what you are building ( a badass rock buggy) I would use an accumulator. LP pump transfer from the fuel cell, keeps it full, even if the tank is low and the pickup is sucking air some of the time. Then the HP pump then circulates fuel from the accumulator to the EFI and back into the accumulator. Don't return the HP back to the fuel cell or you are defeating the point of the accumulator. That maximizes the fuel capacity in the accumulator from just seconds to minutes of fuel capacity.

It also minimizes the amount of HP line you need to run and have handy in a emergency. The LP pump can use any fuel rated rubber, but the EFI hose is $$$.

A single f250 Pump on the frame can be done but it must be lower than the fuel cell pickup. A HP pump is a pusher and not a puller. And any time it sucks air you will lose pressure at the injectors and the motor will stumble.

The f250 HP pumps and LP pumps are cheap and you can get them at any parts store. Important if you are away from home and you have a problem. An exotic HP pump from summit or Jegs could cut a trip short if you have to wait for a replacement.

Just my 2 cents.........

[blazinchuck]

thanks guys...i think that is what i will have to do.

[chuzie]

whats the deal with this weekend?

[744x4]

He He i just ripped out all of my SEFI 5.0 motor and wiring because it pissed me off.I will let you know how the Buggy motor (77 302 with Howell EFI) compares.There are lots of fewer wires in the TB Howell GM stuff and you get better weatherpack conections also.