26 Times

1987 4Runner,22re,5sp,Check engine light stays on while running.Can't retrieve codes,Put jumper in ,Key on ,CEL light stays lit..Replace ecu with new ECU Auto Zone,Plus Mass Air meter,Throttle positioning Switch,Same thing but that ecu runs truck like crap.(ecu by BSE ?)..Put used 1990 and 1988 ecu runs great but CEL stays on and cant pull code.
Can't find broken wire or anything out of place.Cleaned all plugs and connectors.
I see some Yota owner,restoring 1980s trucks and they get new plug ends.IE TPS,MAFS,Injectors,etc,Anyone have a line of formed ,wire harness plug ends or New wire harness (for engine compartment)?

This truck was going to scrap 18 years ago,I ran 13 round trip to the Rocky mountains from RI to volunteer with the USFS/BLM..We where Rover Ralph from the 4-6 miles of 2 land speed events at Bonneville.Been in most every dezert from Black Rock to Yuma.Managed to keep the rust at bay and after 18 years,Id like to get her running right again and would appreciate any help.
Thank you so very much wishing all of you the very best Travels...Sincerely Buggy!-------------------------------------------------------------------------------------------------------------------------
​​​​​​​I FOUND IT! Green wire red strip from diagnostic box to ecu.Wire spade came out the holder at ecu..Thank you all for your great help!73s

Co_94_PU

iTrader: (-1)

Atcfixer will probably remember what is available from where for plugs and pigtails. We discussed it in depth not to long ago, should be able to find that thread if you search..

Ok now your direct question answered.. You don't say why you want them, what kind of tests you have done to the wiring, and stated you have been ECU swapping. This leads me to believe you really need to sit down with the schematic and run some in-depth electronic tests. I'll wager you have a bad wire/connection from the test port to the cabin bay or a short inside the dash..

26 Times

Plug ends are to replace Injector,TPS,Mass air flow plugs.I will search.The plugs are old n brittle,But clean and no broken wires (at plug ends) but not mechanically sound as many tps and injectors get with heat/age...I did run test on Coil,TPS,and Mass air flow,But it was the units not connecting wires harness.
weather here is still frigid and do not like messing around with older wires in this cold.
I was hoping someone had similar problem ,where it was located and color skem of wire I should look for.I will check the wire going to diagnose box but quick look,They are ok.Thank you for your time.73s

kc15842

If you look closely at each connector there is a molded part number. I had a similar issues with cracked and brittle connectors under the hood of our 92. I was able to get new from Toyota or aftermarket just needed to unlock the terminals and push out.

atcfixer

iTrader: (1)

FYI, the older connectors didn't have the part number on them sadly. Around 89 is when that started, and it isn't 100% all connectors, only some.

@OP

Pretty sure I've been talking with you via email. I'm with Co_94_PU, there's probably a broken wire between diag port and ecu. Sadly I don't have a wire diagram for the 87 4runner. You'll also want to be careful swapping ECU's unless you know for sure they are correct (matching part numbers), just because they plug in doesn't mean it will work. I found out the hard way on my 98 T100, burned up 3 coils (coil over plug), and the ignitor.

Anyway, since you said the 1990 ecu worked, I'm assuming the wiring is the same for the 87. My wire diagrams only go back to 1990 sadly, wire colors might be off, but I suspect the pinout would be the same.

Diag port

Just to validate you're pulling the codes correctly, you need to jump E1 + TE1 to read codes, which are pins 3 & 8. Be sure the jumper you use has a good connection. Generally a metal paper clip is used.

If it still doesn't work, then lets poke around (not literately, never poke though the wire insulation lol). E1 which is a brown wire on my diagram goes to frame ground. Take a reading in ohms from that terminal to negative battery post, it should be very close to 0ohms aka short/good connection. If it's a high reading, there's a bad ground connection likely at the intake manifold ground point. Next step on the brown wire, same start location, but we need to test to the ECU. You might have to extend your leads to get a reading. This will make the resistance number go up slightly, but shouldn't be enough to hinder us. E1 is pin 15 on connector C (below) at the ECU, it should also be a brown wire in the connector. Again resistance should be as close as possible to a dead short/0 ohms. If this is a high number or you can't get a reading, you have a broken wire in the harness.

ECU connector "C" (largest connector)


TE1 (or just T as labeled on my diagram for the ECU) goes directly to the ECU. This wire should be violet with a white stripe and goes from pin 8 of the diag port to pin 15 on the ECU connector A. Finally this should also read near 0 ohms, no connector or high resistance is a bad wire.

ECU Connector "A" (Smallest of the 3)



Let us know what you find with the tests above, if all tests well, then maybe there's corrosion in the ECU connectors. Finding the bad spot in the wires might be kind of hard, might be a good idea to track it down encase it's root cause is going to effect more wires (like someone poking the insulation of the wire). If you can't look/find it, you can run a new wire and splice into the harness at the connectors, be sure to use either quality butt crimp with sealing heat shrink (commonly red/pink color) or solder the wire and use a sealing heat shrink also known as dual walled or adheasive heat shrink. NAPA part number 784755 does ok but might be a bit big for single wire. Standard wire for a harness is generally 18 gauge.

For the injector connectors, I'm pretty sure I've found a source for them new and made by AMP (one of the OEM manufacturers for Toyota connectors). It's an updated design that's easier to remove and based on the lower intake I have from a 22re, there's plenty of room for that style of connector. This is from one of my suppliers, so next time I make an order with them I'll have to grab the injector connectors and give them a shot. I'm basing the connector on an 86 pickup intake, but I know they changed a few times, so not sure if 87 4runner is the same or not. I know the EWD i'm using has a different connector for 1990.



The 4 pin connector for the TPS is listed, but the notches don't quite line up right. I'll have to bug my supplier and see if he can find the right one some time.

The 7 pin AFM (Air Flow Meter, similar job as a MAS/MAF) I don't see listed. Might be able to strike luck with my supplier on them, but 7 pin is an odd number which is generally more uncommon to find.

Toyota might have the connectors/pig tails too, but they will likely be $10-15+ each and might take a dealer a while to find the right ones with the connectors not having the part number on them.

Here is a nice thread on the ground locations, in that thread the intake ground I mentioned is #4.

https://www.yotatech.com/forums/f116...-guide-194413/

Good luck!.

Co_94_PU

iTrader: (-1)

atcfixer

iTrader: (1)

Yea wasn't sure if the diag port was added back then or not. Don't have a 22re machine to check in person atm.

Also the ECU pinout was different in 1985 based on the service manual I have, so somewhere between 85 and 90 the pinout changed some, maybe this is the cause of the T/TE1 jumping not functioning. The E1 connection is the same pin if I'm reading the layout correctly (as looking @ the ECU I think).



Here's what the 85 pickup service manual mentions for the diag code reading, probably more accurate than my little write up. Also the wires to test would be on that test connector they show.




Another interesting find, according to this diag tree, they suggest replacing the ECU with the given problem OP is having (section 2).

26 Times

Thank you SO SO SO VERY much.Its still cold up here in Maine so I have been looking for the short..NOW I cleaned all plugs in the Coil and amp area.Got the truck running sweet.So I decided to put the Autozone ECU back In.It ran super sweet,Thought I had it solved.Well took for hour ride,Check EL came on several times.No problem,Run codes in morning.Well CEL staying on No codes.UG.So to cold to move wires around so I will hint the E1 and T..I also purchased a Original Toyota 1987 4Runner Service book.I will #1 Hunt the wires for E1 and T down,..Thank you guys so very much.

atcfixer

iTrader: (1)

Not a problem at all, there's a lot of info to filter though, and the 87 service manual will defo be your best resource. Are all of the ECU's the same part number? I suspect the refurb is probably a different number,but the other OEM ones I'm wondering on.

It's hanging around freezing or a bit above over here in Michigan. In about a week I guess we are hitting 50's. I can feel that spring fever kicking in a little and thinking of the million things I need to do outside lol.

It would be interesting to try to reproduce the whole engine harness, just sourcing all of those connectors is a major job, and it's probably a perfect for for only a couple of years. I might try it some day, but I'm thinking if I get into pig tails first and slowly build up a collection of connectors, I might get enough to cover the whole harness in a year or two. Seems a huge % of 22re engine harnesses are messed up, hacked up, or just plain brittle as can be and falling apart. I think out of 8 or so pickups from this era, I've only had 1 good engine harness that I'd consider selling (reserved for a local buyer atm).

Good luck with the diag work, let us know what you find, it seems there's very little info posted about the check engine light not outputting codes.

Co_94_PU

iTrader: (-1)

If you don't mind please post a photo of the ECU pin diagram from that book you bought (like the one atcfixer shows) for comparison and completeness.. I'm sure there are others out there but it will help people who find this thread when searching for similar problems.

atcfixer

iTrader: (1)

Yea I wouldn't mind any wire diagrams you can find, I'd add them to my collection. Scanners give the best quality, but modern cellphones can take readable photos too, just getting a clear photo with the right lighting can be a little tricky to figure out.