Hi all, I’m working on my next project. An 85 SR5 22RE MT that Sat since 2007. I took everything apart, fix some stuff, and then finally got it to turn over. It cranks, but will not hold an idol and dies immediately unless you give it throttle.

- AFM tests checked out fine
- TPS checks out fine
- If I hold the AFM door open, I can get it to idle (but it’s rough). If I let the AFM door close, it dies.
- If I jump Fp and B+ I can hear the EFI Relay (I think) click but it still dies with the jumper in.
- If I open the AFM door, I can hear the EFI Relay (I think) click.
- I may only be getting 4v at B+ with the key on, but might be getting a faulty measurement.
- Adjusting the idle screw doesn’t seem to do anything.
- I haven’t messed with the distributor.
- Vacuum lines seem fine but I haven’t checked them all throughly
- I also put on all new ground wires just in case (the OEM ones were pretty old) but made no difference of course.

From what I have read, there isn’t enough air being pulled through the AFM to open the door slightly and keep the fuel pump on. Is this correct? If so, what would be causing this?

 

It sounds like the relay you hear clicking isn't the EFI relay. It's the COR relay. I'm wondering if the COR's contacts might be corroded enough to give you problems. Remember that it has 2 halves, basically. One half for the starting cycle and one half for the run time. If the run half is maybe getting stickey, or the contacts are corroded, it may be preventing the fuel pump from running. Especially with the door to the AFM barely open.
The COR is located behind the passenger side kick panel, right above the ECU.

I personally would replace the COR with a new one, and go from there. That's just me though. You do you.
Also, measure the switch in the AFM to ensure that it makes with the AFM's door even the slightest bit open. If the switch doesn't show that it's closed, it may need adjusting, or the AFM needs replacing.
Finally, make sure the TPS contacts make and break according to the FSM. If they don't, it may be preventing enough air from flowing into the engine to keep the AFM door open enough to keep the fuel pump running.

Mainly though, I replace the COR, and then go from there. Once again, just me. It IS a kinda expensive replay, at $65.00 from a dealership.

Good luck to ya!
Pat☺

 

Hey, I swapped in the AFM from my other 85 4Runner and no luck, so I don't think it's the AFM. I then checked resistance on the COR and all checked out fine, but that may only be the starting cycle that is working. About to research how to check the run time half of the COR next.

 

Simplest thing in the world: Hook up everything as though going for a nice weekend drive. With the key on, push the AFM vane open, even a little bit. If you do not hear the fuel pump running, the run half of the COR, or the switch inside the AFM, is bad. You can pull the electrical cable off the AFM, and, while measuring the resistance across the first two pins on the left as you look at, push the vane open. Even slightly is enough. It should read infinity when the vane is closed, and 0 when open.

Remember two things: 1) Remove the negative lead of the battery prior to ohming anything, or it can blow the meter. 2) Never, ever unscrew the two screws that hold the plug body to the AFM. There are small wires attached that can break off very easily.

If the AFM ohms correctly, it's the COR. if not, it's still either the AFM, or the COR. Since you mentioned you recently replaced the AFM, chances are, it's good. Thus, you're left with the COR, or the wiring feeding it, or the wiring to the fuel pump.

Does this help at all?
Pat☺

 

I swapped in the AFM from my other 85 and it made no difference.

I did the FP to B+ jumper to bypass the COR entirely and it made no difference.

So I concluded it wasn’t the AFM or the COR right?

 

I believe that's correct. It sounds like wiring in that case. The wires on the fuel pump hanger are known for their brittleness. Check that you're getting good voltage at the top of the hanger. Also, ensure that the ground wire on the fuel tank is in good shape. The ground wire, IIRC, goes to the frame. Being under the truck, it can corrode fairly easily, at both ends. The end on the fuel pump hanger, and the end on the frame. When you check the power, check it across the two connections on top of the hanger. If it's not good there, check it at the power connection, then at the a scraped clean point on the frame, not the body metal. If it suddenly checks good, the ground connection is bad. If it's bad, it's the wire to the power lead. If it does check bad, find a connection, about 1/2 way between the COR and the fuel tank. Good there, you know which way to go to check it again. Keep "splitting" the system in 1/2 until you've found the bad place. Remember, it could be a connector, or just a bad place in the wire.

Remember the wiring to the AFM AND the COR. Often, tthe connector under the COR gets water in it, from a leaky windshield, which causes the female connectors to corrode. Little things like that can make a huge difference. Make sure the EFI fuse is good. Ohm it out, don't just look at it. I've found so many automotive fuses that look good, but ohm bad. Your multimeter is a super good tool for you.

I wish you all the best luck...
​​​​​​​Pat☺