RedneckBatmobile

iTrader: (2)

Recently I have been working on my 86' 4runner. The PO sold it to me non working as is with a "fuel related issue" being the cause of its not working. The problem is that the fuel pump is not getting fuel to the intake of the EFI system. The engine runs and starts instantly with starter fluid in the intake.

I started out with the fuel pump and found that it was functional and when i did a direct connect of power to it, it ran and pumped gas easily all the way to the front. I started checking wires and the continuity between the front and the back and so far everything has been fine.

Upon checking the wiring diagram, i realized that there is a relay directly in contol of the fuel supply right after the wiring harness near the pump, and this relay is located in the passenger side kicker panel. I tested the relay itself to make sure it wasnt junk, and then preceded to check the relay on the actual electric system. So i hooked up a volt meter to the output lines off the relay to see if the fuel pump wires were getting any juice. When i turned the key and cranked the engine the voltage goes instantly up to 12 or 13 volts, but then drops down after about 1 second to less than 1 or 2 volts. I dont know if this is supposed to happen, and i honestly dont know where else to look.

I checked the air cleaner switch, the EFI main relay and wires all the way up to that fuel relay. Any help would be MUCH appreciated.

4Crawler

iTrader: (3)

Did you try the fuel pump test jumper?
- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

Hadmatt54

The relay that you have found is the Circuit Opening Relay or you will see it refered to as "COR" for short. Here is a link to a detailed description of how COR and the fuel pump works. The section that applies to your truck starts at the top of pg.7 and ends at the middle of pg. 9 "Two Speed Fuel Control. This should help you alot.
http://www.autoshop101.com/forms/h42.pdf

jjbruney

Had the Same problem with my runner turned out to be the COR. When you turn the key on the fuel pump will prime then shut off so the motor will start and run for a few seconds then dies as if it's running out of fuel this is because the COR is not closing after start up to allow the fuel pump to run. Mine failed from moisture it's like $100 bucks at the dealership

RedneckBatmobile

iTrader: (2)

so i tried the jumper cable between terminals fp and b+ and nothing happened. i had my friend in the back with a voltmeter at the fuel pump and i was still getting nothing power wise to the back there. the COR was clicking when i had the jumper so maybe i wasnt bypassing it correctly? do i need to do anything with the AFM when i jumper the cables?

i also have a bigger issue regarding my engine/wiring harness, but considering it ran for the PO i dont think that is the cause of my problem. i have been looking through alot of FSM pages and realized that the 22RE in my 86' is actually an 85' engine. thus there are some cut vaccum hoses that are nonexistant on an 86 and others that are only in diagrams for an 89. i also feel like im missing some things in my fuse panel, but i have no idea. i cant remember on my 89' what i had compared to this. my main concerns are what i can best describe as a VSV located on the back of the valve cover on my engine. it has two vaccum hoses (both cut) with no homes, a factory plugged vaccum hose connection in the back, and a plug into it from the wiring harness that comes up through the space between the EFI injection module and the valves. the fuel line is a backyard mechanic fix from the PO because the old fuel line rotted out. planning on replacing that soon.

any help would be awesome? thanks

the VSV type thing located on the back of the RE. both lines im holding are attached to it and the plug bleow those lines is a random mystery that comes out of the intake wiring harness:
http://s1121.photobucket.com/albums/...t=DSCN0462.jpg
close up:
http://s1121.photobucket.com/albums/...t=DSCN0461.jpg
looking down on it:
http://s1121.photobucket.com/albums/...t=DSCN0459.jpg
fuse box:
http://s1121.photobucket.com/albums/...t=DSCN0456.jpg
passenger side kicker with COR and Engine Control:
http://s1121.photobucket.com/albums/...t=DSCN0451.jpg
fuel pump jumper:
http://s1121.photobucket.com/albums/...t=DSCN0447.jpg

hope the pictures help..

4Crawler

iTrader: (3)

If the CO relay is clicking then it is getting turned on and off with the ignition. That is 100% normal, relays click when they get energized:
- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

But, as noted on the page above, the relay contacts may be burned/pitted/dirty or the wiring between the relay and the pump may be faulty. You can test the CO relay itself:
- http://www.4crawler.com/4x4/CheapTri...ORelayLocation

Some '85 vacuum hose info below:
- http://www.4crawler.com/4x4/CheapTri...ine_Pix/1.html

RedneckBatmobile

iTrader: (2)

so it turns out the relay in the truck right now is for an 88-95. dont really know how that happened, but if the PO got it to run with this in the harness id be very impressed.

anyways i ordered a COR yesterday for an (1986/1987) so once it gets here i will throw it in and try and start her up. we checked wires all the way back to the fuel pump and they are good resistance wise so im crossing my fingers and hoping this will fix it!

btw, props to 4Crawler for creating such an awesome resource. I've used quite a few tips already. Thanks!

half cocked irishman

So if the COR isn't sending 12 volts down the light blue fuel pump wire wiles cracking then its shot? Cause I had put a cor from a different toyota pick up in mine then tested efi main relay and determined that was bad. I tried bridging the efi main from the black wire (to the cor) and the other port to the 15 amp fuse for power. I turned the key and my fuel pump kicked on for a second then off like most vehicles do. I turned key off and tried it again and got nothing. I replaced the efi main and turned key and got nothing again. It fired and died instantly. I test for volts coming out of the cor to the fuel pump and only got 9.6 when it started not while cranking then it died and I had nothing. I need some advice to tell me if this is normal operation or not.

4Crawler

iTrader: (3)

Does note sound normal, see below:
- http://www.4crawler.com/4x4/CheapTri...ORelayLocation

half cocked irishman

So my problem started while I was in the trails going up a muddy hill, I was bouncing a little bit and lost my fuel and have had this problem ever since. I have double triple and quadroople checked connections and I'm still here. I've determined COR is good now. Could my ecu just be fried? How do I diagnose the ecu?

4Crawler

iTrader: (3)

Well, you could try the fuel pump test jumper (if you have not already done so) and that will hold the CO relay on/keep power to the fuel pump and if the problem vanishes then see why the CO relay is turning off. The ECU does not control CO relay while running, the AFM does. Might check the AFM wiring. I had an issue with that once where my engine would start to sputter and die under acceleration. Finally the ECU flashed an AFM code and that led me to that issue. Fixed the wiring (loose connector) and the problem was solved. You could also hook up a volt meter to the fuel pump and then next time it dies, see if the pump is getting voltage or not.

half cocked irishman

Pump definite pumps when bridged and I've tested afm and it works as well.

4Crawler

iTrader: (3)

To reiterate, does whatever problem you are having go away with the test jumper installed or not? If it goes away, then find out what is dropping out the CO relay. If it does not go away, find out what else is wrong. That is if the jumper is installed and the fuel up is still running and the engine dies, then something else is causing it to die since you likely still have fuel.

half cocked irishman

With the bridge on the check connector. It starts and runs for a second then sputters out but the fuel pump continues to run after it dies.

4Crawler

iTrader: (3)

Well, air+fuel+spark = engine running. Sounds like you have fuel, at least to the injector rail. So find out what else is wrong. Might even be a bad injector wire splice that is shaking loose after running a bit and causing the injectors to lose their ground signal from the ECU.

trento

my 85 22 re wont start when warmed up.It always starts when it cools down.the pump runs when i jumper it out at the tester.i swapped in a used pump and the problem vanished for quite some time.Now it's back.Same thing happened to a buddy's rig.same engine.does the pump get funny with age?any ideas?thanks guys

fuzzyhead

Is this a typical problem? I'm looking into an '87 turbo and the owner says that it runs but when you get going a little bit it bogs down. He says that a few shops he talked to said it was the fuel pump. He's 3 hours from me, so I want to make sure I have a fairly good idea of what I need to fix it to drive it home.

Does this sound like the fuel pump/COR? Thanks.