toyotruggie

I have a fuel cell for my 87 toyota wondering what fuel pressure it runs at so I can get the right external fuel pump

wyoming9

iTrader: (1)

It depends on just what engine you might have!!

It could be almost anything you need to adjust your fuel to the demands of the engine.

toyotruggie

It is a 2.4l was carburetor but I put a efi system on it from what I'm reading it sounds like it's 190lph but I want to make sure that it is right before I go spending money on a pumo that is to high of pressure

AKHeathen

what efi system? many carb-to efi swaps call for like a 7/8 psi or 15psi pump....... and some like a 50-60psi inline...... you might check the manual for pressures.... that will tell you far more that we can on the unknown info you posted

toyotruggie

Don't know what system it is but ik that it runs great off the fuel pump that's in the tank but the tank leaks so I'm switching to a fuel cell

AKHeathen

it was carbeurated, yet you say there is a pump in the fuel tank? that does not match. carbeurated engines have mechanical fuel pumps off the cam gear. look up the efi system and find out.

toyotruggie

Found out from previous owner that It is a 87 4 runner motor efi and the fuel tank was out of it. I'm going to hook a pressure gauge to it tonight cuz it has the constant amount of pressure weather it's running or not cuz I ran it off a toggle switch

scope103

A Toyota EFI system needs 38-44psi http://personal.utulsa.edu/~nathan-b...87fuelpump.pdf on the rail (it depends on intake manifold pressure, which depends on throttle position). To get that pressure, it pumps out more fuel than it needs, with the "excess" returned to the tank via the Fuel Pressure Regulator.

"190lph" is a flow, not a pressure. There's no published spec on the flow (and it would only be useful if it were "flow(lph) at xx pressure(psi)"). But we can guesstimate it: If you mash the throttle at 60mph, your mileage shouldn't be less than 6mpg. So that's 10gph or about 40lph at pressure. So as long as your pump can hit 50lph or so at pressure, it shouldn't matter.

Of course, you don't have a Toyota EFI, but I doubt that it requires significantly higher pressure at the injectors. And unless you're hoping to be getting much less than 6mpg, it shouldn't require much more flow.

AKHeathen

there you go, if it's stock toyota efi, then you have the numbers for the fuel pump requirements for the fuel cell pump.

toyotruggie

Ok so now that I have the numbers I still can't find an external fuel pump that will work and give me that pressure

AKHeathen

what can you find that's close, but more than that? like 50psi 60lph?

toyotruggie

Would 50 psi flood it out

scope103

The pressure on the rail is determined by the FPR, not the pump. The pump just has to put out "a little more" pressure than needed, so the FPR can clip it off and send the excess back to the tank.

While I haven't reviewed all the hydraulics of the fuel system, I expect there is no such thing as too much fuel pump pressure. The actual flow rate will be limited by the supply lines, so I doubt the FPR could be overwhelmed and not be able to send enough back.

So 50psi, being more than 44psi, oughta be enough. But you haven't provided all the necessary stats. If that pump will put 50psi into a closed valve, I doubt it can put that much pressure at the end of the line while flowing 50lph. I assume that you're shopping among fuel pumps, and I hope that the vendors know what you're using them for, so the 50psi figure means something like "I can assure 50psi at the end of the line with any reasonable flow rate."

AKHeathen

The flow rate would be determined by the line size, which i think is 6mm, and I'm sure it can reach the same pressure through the line. there would be a pressure drop if consumption exceeded the flow rate of the main line, but that's not going to happen on a stock motor... now say if you got a 100psi 20lph pump it would overrun and you certainly wouldn't maintain pressure. or, if it was too large, like 100/400, it would also build pressure high at the pump and do something like you described, but that's why we are matching it better. it can be bigger than factory running requirement and the factory pump is when new.

toyotruggie

So I got a fuel pump and need a regulator. I have found some on ebay that and a Guage and such. Do u put it on the supply or return line?

AKHeathen

Is your factory regulator faulty?

toyotruggie

Idk the vacum line has a screw in it how can I check to see?

AKHeathen

Measure fuel pressure while running. is the screw blocking the vacuum or return fuel line? if there is no return, then you can get an in-line adjustable one..

toyotruggie

It has a return line for the tank but idk if it's hooked up. So if it is not hooked up then I can put an ajust able fuel regulator on the supply line up by the rail?

AKHeathen

Or by the pump. if it has a good return line hooked up, then a factory, or factory style is better on the pump and injectors, when the vacuum is working. it should be hooked up to manifold vacuum somewhere, so it lowers the pressure at low loads and also keeps the pump from working so hard.