Bought this 4Runner a few weeks back, 88 3.0 5spd. 209k on it, with 30k on a rebuilt 3.0. When I bought it it was showing a code 11. Changed the ignition switch, that cleared, and it was then showing a code 22. Replaced the coolant temp sensor, still throwing the 22. Started hitting the wiring harness with a multimeter to see what the ECU was getting, was not getting voltage readings on anything on the ECM.. and when I did get a reading it was typically very low, 8volts tops.

Started tracing the E1 (body ground) wire, removed some electrical tape and found this:



I'm guessing that wiring is not supposed to look like that. And that I'm probably going to need a new wiring harness if I want this thing to run right.

Where does the E1 wire run to, the diagnostic port? I was expecting it to ground off somewhere in the cab under the dash but it looks like it goes into the engine bay. Haven't disassembled under the hood yet, washed up to come share what I found before moving any further.

 

Those are just the shields for wires which are grounded to the body grounds. Pretty sure its suppose to be like that.

 

So should I be getting a new ECM then?

 

Um...no.

Anywho, E1 is the engine ground.

It sounds like the only issue you need to resolve now is the code 22. So if you replaced the sensor there's probably an open/short in the THW circuit somewhere.

PS, I'll be surprised if changing the ignition switch solves the code 11 issue permanently. We'll see...

 

I changed the ignition switch and the EFI relay and the 11 went away.

THW circuit? Sorry, I'm not up on all the acronyms for these trucks. Whats the test on that to see if I've got a short?

 

EFI relay might do it.

On page EG2-192 is how you check the THW(ECT Sensor) circuit to determine the cause of code 22.
http://personal.utulsa.edu/~nathan-b...86troubles.pdf

Here's how to test the ECT Sensor itself.
http://personal.utulsa.edu/~nathan-b...98engineco.pdf

Here's the entire 93 FSM/your homework.
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

Careful there, because there's some significant differences between the 88 and 93 3VZ-E. So don't be afraid to ask if something isn't like it says in the 93 FSM. There's hardly anything else to reference online regarding it. But I know all things 88 3VZ-E, so you're in good hands.

Well, not all things. But as close as it gets.

 

I guess you'll need this...

And this for starters...


Both are for the 88 3VZ-E.

And here's the 88 3VZ-E wiring diagram thread.

 

on the bright side, I have a complete, unmolested harness from an 88 3.0 5speed Sr5 4runner that I would put on you if you need it!

 

Forgot to answer that. So here's another searchless freebie pic of the inside cover sticker showing which terminal it is in the diagnostic link/check connector.

 

Thanks for the help, MudHippy, I appreciate it.

I'm gonna buy a new multimeter today. Mine's not reading right. I tested a known good 9v battery and got a .01 volt reading... and when I tested my 4Runner's battery on a 20 volt scale, it didn't read. then on the 200 volt scale it was reading 35 volts.

20 bucks... cheap insurance before I go any further.

 

I'll keep it in mind if I find anything really ugly, thank you!

 

confirmed bad multimeter.

I'm getting readings on the ECU now! All is not as bad as I thought.

 

I've been running through these tests and everything is showing good at the ECM as far as voltage.

Resistance is fine per the ohmmeter at the temp sensor.

So wiring or ECU?

Can I test the end of the coolant temperature sensor plug the same way I've been testing the ECU ports? If I got no reading there, would that mean the wiring is bad in between the two?

 

Still no fix on the code 22. I keep getting an intermittent code 51 as well, so I pulled the throttle body to test the TPS. Was way out of spec, was not able to get it in spec, appeared to have a dead spot, opened it up, and sure enough one of the contacts was busted. Have a new one on the way.

Hoping that solves some of my running issues. CSI is testing fine with my new multimeter. Have not found any bad wiring and I'm tired of staring at wires already.

I may end up taking it to a shop to diagnose the code 22 at this point.

 

I am not much help on the 3.0, but I have a link for the grounds. The triangles are supossed to be the grounds. These trucks like their ground wires. Maybe this will help.

3.0 Grounds....http://www.ncttora.com/FSM/1990-1995...c/connecto.pdf

 

I give up. Replaced the TPS, spent a long time getting it in spec, now the truck's throwing a 41 in addition to the 22.

Taking it to someone for an estimate then determining if I'm gonna keep it.

 

So I drove the 4runner yesterday.... rather unsuccessful drive.

Got about 6 miles or so from home to meet some friends for lunch, then got about 2 miles back towards home when it started surging again, then stalled at an intersection, and has refused to start since.

It will crank, and occasionally seems to "start" but then immediately dies, doesn't even get up above 200rpms

The fuel tank is full. I wanted to run some seafoam through so I poured in a bottle of that and filled the tank before heading to lunch.

The computer is now throwing the code 11 again.

If I jump FP to B+ I can hear the fuel pump running, but it still will not start.

any thoughts on where I should be looking next?

 

Not surprised.
Replace the COR(Circuit Opening Relay). If that doesn't do any good, then the problem is most likely the ECU. Or possibly a serious wiring issue, but not very likely. There's too many things going wrong at once for apparently no reason to be anything else really.

Hint: The COR is behind the passenger side kick panel, above the ECU, bolted to the body.

 

Thanks. I have an Ecu on the way. There was a pair of them for my specific truck on eBay for a steal last week, so I snagged them just in case. Should be here Thursday.

The COR is dealer only, correct?

 

RockAuto has them listed as a fuel injection relay, and as a fuel pump relay.

http://www.rockauto.com/catalog/moreinfo.php?pk=39237

You might find them other places too. I haven't really looked that hard.