j0rdanisme

Quick question,
The fuel pump in my 91 pickup has burnt out. The wiring was tested up to it and its fine, but the pump does not start when its turned on. Here is a quick story of what happened.

I recently took my truck out of storage for 4 months. It ran ok, but when i hit the gas the RPM's would jump, then fade off quickly. I thought that it could be lack of oil, but i checked it and its clean and correct. After charging the battery again I started it up, it ran fine for about 4 minutes then just cut out. After that it would turn over, but wouldn't fire. I got the wiring tested and its all good to the fuel pump, but it wont turn on when I attempt to start it. I got it checked at the shop and they said that the injectors are not firing either, but i am hoping that is because fuel is not present in the rail.

tl;dr was running, stopped running, wont start but will turn over. Sparking, turning over, power but no pump action from fuel pump.

From some research i am pretty sure the fuel pump is a standard 2" 45-50psi in tank fuel pump. Is there any known domestic vehicle that uses this? easily accessible at pick-a-part?

Also, my plan is to chop a square in the bed of my truck to access fuel pump. Anyone know general placement measurements?

Thanks for reading!
Yotanewb'

j0rdanisme

Bumpity bump.

Hadmatt54

Unless there is something different in the 90's trucks, the injectors not firing should not have anything to do with no fuel pressure. There is a fuel pressure up VSV, but all this does is increase the fuel pressure for hot engine starts. I'd check and see if you might have an EFI relay problem.
Almost any Toyota fuel pump should work. Standard pressure is 33-38 psi. If you have a 22re then a standard 4 cylinder pump should work fine. I did a 5m-ge conversion on my daily driver and the 6 cylinder pump though larger in diameter fit on the pump bracket with no modifications. You will need a certain amout of slack in your fuel lines to pull the assembly out of your tank, even with the plate built into the 4Runners if my memmory is correct you still have to disconnect the fuel lines to get the assembly out. Cutting a hole through your bed may not give you the results that you want. Dropping the tank is not a huge job and even in Chilliwack you should not have the rust issues that we have here on the East Coast.

theMonch

I wouldn't cut the bed either. I would drop the tank, or pull the bed. In the long run it's the "right" thing to do.

When you say that the mechanic says that the injectors aren't firing they probably confirmed this electrically and not mechanically by pulling an injector. This would lead me to believe you have a EFI relay issue. The EFI relay is energized with the ignition switch which feeds the power to the injectors (as well as other motor related systems) and also powers the COR (circuit opening relay) which powers the fuel pump. If you had a problem with this relay then it would definetly effect both systems.

The only problem with my diagnosis is that you are saying that you have power to the wiring right up to the pump. If this were so, the EFI relay and COR would have to be functioning.

4 months isn't a terribly long time for a Toyota to sit and develop a storage related issue, especially if it was stored indoors.

Have you drained the gas and put in some fresh stuff to see if it is just fuel quality related?

j0rdanisme

It was always store indoors. I have not drained the fuel tank, but i did put fresh gas in it as i thought it could be a lack of ocatne. It had about a 8th of a tank of gas when it went into storage, and i put in another 8th at least. Do you possibly know how to do that easily? If I am dropping the tank already, it should be fairly easy at that point

It sat inside for the whole storage.

I will do some research on the EFI relay. Thanks for your input, I will keep you posted.

4x4runr

Check the EFI fuse or all the fuses for that matter....

theMonch

Oh and if you want to check the fuel pump there is a diagnostic connector that is under the hood connected to the fuse block that you can jumper that will directly engage the fuel pump, bypassing both the EFI relay and the COR relay.

Do you have the FSM for your truck? If not there is an 93 version available here.
http://www.sontt.com/forum/viewtopic.php?f=5&t=44

It should be the same.

j0rdanisme

Do you happen to know the section of that FSM its in? I can't locate it.

tried4x2signN

B+ and Fp.

But be ready b/c once you jump those two and presuming the battery's got juice, it'll be pumping fuel...

I once did it to try and bypass a security system and purge the fuel... I had a nice gas mist and no smoking section for a while...

theMonch

It's in the "engine" subfolder under fuel pump. The pdf file name is "28fuelpump.pdf"

j0rdanisme

Is there an easy way to wire my fuel pump directly up to see if it cycles?
I have my gas tank all out and so forth. I know its 12V, am I able to directly wire it to my battery?

Cheers.
Yotanewb'