I didn't get a lot of feedback in the 84-85 4Runner forum, so I figured I'd post here. This is a 85 SR5 22RE Manual Transmission that Sat since 2007. I took everything apart, fixed some stuff, and then finally got it to turn over. It cranks, but will not hold an idol and dies immediately after the cold start fuel is burned unless you give it throttle. If you give it throttle (by pushing the pedal down or holding open the AFM), it will run pretty good. As soon as you stop giving it gas though, it dies instantly.

- AFM tests checked out fine (I even swapped in the AFM from my other 85 4Runner that I know is good and it had no affect)
- TPS checks out fine
- If I hold the AFM door open, I can get it to run. Then if I let the AFM door close, it dies immediately
- If I open the AFM door, I can hear the EFI Relay (I think) click.
- If I jump Fp and B+ with two male spade connectors in the test connector in the drivers side wheel well, I can hear the EFI Relay click (I think) but it still dies with the jumper in.
- If I jump Fp and B+ and turn the key to Start, I can hear the Fuel Pump Running constantly until I turn the key off
- I am only getting 4v at B+ with the key on, but this might just be getting a faulty measurement?
- Adjusting the idle screw doesn’t seem to do anything.
- I haven’t messed with the distributor or tried resetting the timing.
- Vacuum lines seem fine but I haven’t checked them all thoroughly. I do have all new vacuum lines and will install them soon.
- I also put on all new ground wires just in case (the OEM ones were pretty old), but it made no difference of course.
- I know the EGR is clogged (it's on the to-do list), but surely this isn't causing the issue right?

So, what should I test next? correct? If so, what would be causing this?

 

Clean, or replace the EGR. It CAN cause the problems you're seeing. Also, ensure the PCV is functioning correctly, and the rubber air lines from it the the Throttle Body, and from the TB back to the valve cover are in good shape. The grommet holding the PCV in gets old and brittle fairly quickly, so beware of it shedding chunks down inside the valve cover if/when removing the PCV. It's safest to leave the PCV in the valve cover, remove the valve cover from the engine, then pull the PCV out, if there's any doubt about the grommet. That way, any thing that falls off the grommet won't get down into the valve train.
It's also a great time to replace the valve cover gasket, and adjust the valves, should they require it, since you have the valve cover off anyway. It's cheap and easy to replace. Just a thought.

With Fp and B+ jumpered, you should hear the fuel pump run with the key in STArt or ON, both. If you don't hear it run in ON, you may have a COR with a failed RUN half.
The voltage you're reading at B+ with the key ON, you may be reading what's called a "ghost voltage". The current flowing through the wires to the fuel pump is developing a voltage your meter is reading. Check the battery voltage at the battery.

Could it be that the large tube between the AFM and the Throttle Body has an air leak? The corner pieces are especially prone to developing cracks, which leak enough air in at idle to let the AFM close, shutting the fuel pump off. Also, is the Idle Air Control Valve closing completely when the truck is warmed up? If not, IT may be allowing enough air in to shut down the COR, thus turning off the fuel pump.

I mean no insult, and not that *I* have ever done this <ahem>, but the Idle Adjust Screw you adjusted was the one under the large screw on top of the Throttle Body, not the large screw itself? That large screw is just a cover for the IAS. Adjusting that will not change the idle at all. Also, did you check the o-ring on the IAS? They can get old, brittle, and have small pieces fall off, and down into the small air channels below the IAS. The right size o-ring is a common one, readily available.

Sorry, I ramble. I hope something is small help...
​​​​​​​Pat☺

 

First, thank you for your help!
Okay, I'll get on the EGR soon then - I didn't know it could be an issue. When I had it removed, I cleaned it but the smaller hard air line was completely clogged - I tried to unclog it with a bunch of different methods (including a coat hanger) but no luck, so I just pushed it off till later. The PCV should be good as I replaced it and checked the hose (it's pretty new) when I had the valve cover off while doing a bunch of maintenance items.


Battery voltage is 12.6v. With Fp and B+ jumped, the fuel pump is running in Start or On. I also got 12.2v at B on the COR plug as well and 12v at the fuel pump with or without the jumper in, so I don't think it's the COR.


I checked this too, no leaks. The corner pieces are actually better than some that I've had, still flexible and everything. They actually still sell these at the dealer, but I didn't get one because min was so good.


I checked the o-ring on the IAS and it was fine (so good that I didn't replace it with a new one I have. I'll double check the idle adjustment screw and make sure I'm tweaking the right one This is on an 85 (so older TB) and it's the large screw you adjust with a flat-head that has a black o-ring at the top and fine threads the rest of the way down. I'm not sure there is any other screw on mine, but will go out there and check for sure! This is the same screw I use to adjust the idle on my other 85, so I'm 99% sure I'm doing this part right !

 

This is the IAS I am adjusting

 

AHA!
Sounds good, anyway.

That, sir, is the cover screw. Take it all the way off, and under it is the Idle Adjust Screw. A smaller, brass colored screw. If adjusting the cover screw makes any change in your idle, then the o-ring on the IAS is bad.

It's easy to check: Screw the actual IAS all the way in until it bottoms out, carefully counting the number of turns, and partial turns, until it touches bottom. Don't tighten it TIGHT, just until it stops. Then, you can unscrew it all the way out, until it comes loose. Examine the o-ring on the bottom of it, checking to see if it has dried out, or gotten brittle from age. Rubber does that, after all.

Like I said, it's readily available at any number of places. Auto parts stores, hardware stores, Grainger, even Harbor Freight, often. Usually as part of a set, or kit. They are very inexpensive.

Check the small air passages under the IAS for little bits and pieces of rubber, and clean them carefully of any debris. A Q-Tip, with a little Vaseline on it will pick up small bits pretty well, then clean the Vaseline off with a couple of clean Q-Tips.

Anywho, a tip to make the o-ring, or any other rubber part, last much longer, and seal better, is to rub a thin layer of Vaseline, or Silicon Dielectric grease, on it before you install it. Then install it onto the IAS, and reinstall the screw into the Throttle Body. Screw it down in until it bottoms out, then back it out the number f turns, and partial turns, that it had on it originally. Start your truck, and let it warm up completely, maybe even tapping the gas pedal a few times. Then, using a external tachometer, check the idle. It should be about 850 RPM. You can adjust the IAS until it's got the correct idle speed. Use a tach external to the truck. The gauges in the built in gauge set, the one in the dash panel, are notorious for being inaccurate.

Good luck!
Pat☺

 

I just went out and looked and neither of mine have any smaller screws below the one I showed above. It just goes straight into the TB. And when I adjust the one I pictured above, it definitely adjusts the idle and the o-ring doesn’t seem bad (super flexible and stretchy, I can take it on and off no problem).

Am I somehow missing something? Again, maybe the 85s are different?

 

Hello folks, first post here! one morning while at the same time heating up my 1985 Toyota pickup I fired it up, everything was ordinary however following 5 minutes of heating up it out of nowhere bitten the dust. At the point when I attempt to restart it would begin fine and dandy, Inactive for a couple of seconds and afterward bite the dust. . . each and every time. after looking into it further I saw that one of the admission boots had amassed a tear on it so I fixed the tear, reinstalled consumption boot and the truck was running once more.



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