daddio

Hi All,
Having fuel problems in 86 4runner that was sitting. Runs briefly then dies.
This 86 has a carburetor fed by an aftermarket electric fuel pump mounted on the firewall. Engine does not have the cam for mechanical fuel pump, and the plumbing has two lines running from the tank (like an EFI?).

Did they make carb vehicles with electric pumps? (in-tank or firewall?) Or was this an EFI converted to carb?

Should I get another electric pump? Or install the cam and go for the mechanical pump?

thanks

old87yota

How long has the truck been sitting?

If its been awhile, drain out any old fuel and change fuel filter if not done recently.

If the engine is original or swapped engine from 1985-1995, then you most likely have an engine that was originally EFI and swapped to a carburetor set up later on. The carbureted trucks from this generation had mechanical fuel pumps and the EFI came with electric fuel pumps.

I am not sure what steps you took to say the fuel pump was the problem.

You can go either way on this... I guess it depends on whether you want a factory like set up or not.

wyoming9

iTrader: (1)

All fuel systems for the most have a supply and return line

The heads of the engine all came with the plate in the head it is just a matter of installing the fuel pump eccentric on the cam .

Does the fuel pump run ??

I think you might have other issues maybe water in the carb.

daddio

already drained out the old gas from tank and added new. Also cleaned carb.

The electric pump on the firewall pumps runs for a while, gets hot, then stops.

wyoming9

iTrader: (1)

Electric pumps always push better then pull .

That is why most aftermarket ones are mounted as close to the tank as possible.

Hooked to the return line instead of supply side

It does not fill the fuel bowl and shut off.

Maybe the wrong pump and it is just pushing past the needle valve dumping gas into the intake and what ever intake valves are open.

Carb engines need @ 3 to 5 psi EFI need @ 30 to 40 Psi these numbers are from memory might be a little off but close enough.



Is there a fuel pressure regulator??

Has this engine ever run since the conversion to a carb??

All carb engines came with the mechanical pump

The fuel injected had the pumps in the tank except for some of the 82/83 celica`s had an external electric pump

Terrys87

iTrader: (1)

All runner 85 an up were fuel injected. Any I have seen that they tried to convert to carb is usually butchered up real good.

If you want to use the mechanical fuel pump, all you need to do is get the dish cam gear to drive the mechanical fuel pump. If you can find a junked 22r motor, you will see it easily converted over to a mechanical pump. That would be how I would do it.

daddio

yep, this one ran for 3 years with carb and firewall mount electric fuel pumps. No pressure regulator. Vaguely remember the pumps didnt last.

Is there a good quality 3 psi pump to use temporarily? Maybe an in-tank mount, but 3psi for carb system?

Eventually would prefer to convert to mechanical pump when I can get the eccentric cam. If so, I assume just deletee the firewall electric pump. But if it was once an efi, what about the (dead?) pump in tank? - just leave it there??

Terrys87

iTrader: (1)

I would bet they removed the pump in the tank and extended the hose for the line to reach further into the tank. If they just removed the fuel pump, you would run out of fuel at about half tank. I am not sure if the firewall mounted pump could pull fuel thru the old pump.

It is possible that they used the "J" line as a supply line which is the Return line.