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Need Help Diagnosing: 22RE Ignition or ECU failure, other? 86 4Runner Dead w/Code
Hey all... looking for help diagnosing and getting advice on where to start fixing. The engine quit running after running beautifully, practically no warning, and now won't restart. Battery is plenty strong.
Over this summer, a good friend did a LOT of work on my 1st 4Runner, a lot of it was engine related, though I don't believe what just happened to me was related to his work. After about 1000 miles of driving following the work, everything was running great - better than ever in fact. Then one night I was driving with my kid. We had just left a place... started the truck from warm, drove about 5 minutes and I then I pulled over to look up where we were going next on my phone. We idled there for about 5 minutes. Then I pulled back out onto the road and going through a slow downtown area my engine started to surge like I was pulsing on the gas pedal. My kid was like "stop it dad, I know you're playing around". The truck kinda jerked along having trouble to drive, so I pulled over. It was running really rough and struggling too keep running without working the gas pedal. In neutral I tried to rev it but it was struggling to keep running. It died, I restarted it once but it wouldn't keep running. After that, no matter what, it turns over fine but will not start.
Diagnosis steps so far:
- Jumpered the diagnostic plug by the driver fender well under the hood and turned key ON
- Check engine light blinks 6 times
- According to this chart: https://www.4crawler.com/4x4/CheapTr...es/index.shtml this is what may be going on:
6 No engine revolution sensor (Ne) signal to ECU
- Ne being over 1000 RPM in spite of no Ne signal to ECU
- Defective Igniter circuit
- Defective Igniter
- Defective distributor
- Defective ECU
What I know leading up to this:
In the past when seasons would change, I noticed the truck had trouble starting. I changed the cold start time switch and that improved things. But there have been times where I still suspected that fuel flow might be an issue, and maybe the fuel pump was going bad. But after this event, and having the info that suggests an ignition issue, I thought of something else that has been happening... when cranking the engine to start, it would often start with a "boom" (for lack of a better word), as if there was either insufficient fuel or spark and then it would detonate hard at first ignition. Also, the water temp gauge has been intermittent lately - sometimes totally dead/zero temp, sometimes normal. No overheating though.
So now I'm suspecting maybe spark has been the issue and not the fuel flow and maybe something in the ignition system just gave up the ghost?
Sorry for the long winded post, trying to give the important information and some back story for anybody who may want to help.
Just in case, for reference, here's what was done to the engine/drivetrain in one project, completed around 1000 driven miles ago:
new timing chain, metal tensioner, cover gasket, water pump from upgraded LCE kit
valve clearance adjustment
new valve cover gasket
new clutch (transmission pulled, inspected, seals changed)
new clutch master & slave cylinders
transfer case oil changed and new seals
oil change, new filter
new oil pan gasket
new alternator/fan belt
new heater fan resistor
new air intake hose
Not under the hood, but the rest of the same batch of work done over the summer:
driveline rebalanced, reinstalled properly in phase
OME 2.5" front and rear lift installed (minus torsion bars, were backordered)
from your other thread, your windshield leaks. the ecu is in the passenger front footwell, and when the windshield leaks on that side, the water drips right onto the ecu. if it has been doing this for a long time, it is entirely possible that your ecu is damaged by the water. perhaps it worked intermittently for a while with the leaking, and now it is more "permanent". something to check, anyway.
from your other thread, your windshield leaks. the ecu is in the passenger front footwell, and when the windshield leaks on that side, the water drips right onto the ecu. if it has been doing this for a long time, it is entirely possible that your ecu is damaged by the water. perhaps it worked intermittently for a while with the leaking, and now it is more "permanent". something to check, anyway.
I don't think I ever replied previously... thank you for this suggestion. This is very helpful and I'm going to look into this. At this point I'm thinking that it's actually fuel pump related as I can't get any fuel to leak from the banjo bolt at the cold start injector when I loosen it (with and without the fuel pump jumpered and with and without the engine cranking).
I had a bad internal wire connection to the plug where the for the distributor and ignitor connect that produced the same exact symptoms. Carefully wiggle all of the wires from one end to the other with the truck idling.
Sounds like how mine acted when my fuel pump died. Mine was running great, stopped and went into store, drove away fine. Then within a few miles was losing power and jerking. Then it died. It would crank but not start.They can die for no apparent reason. Had to have it towed home. New fuel pump and good to go.
You tried running with the FP test connector jumped? Heard/Felt fuel pump work?
"SEE" if fuel pump works?
The following is hard to test and is better "seen/felt" (inspected): Crimps connecting ALL between injector negatives, AND ECU pin 10 AND ECU pin 20. Corroded? Broken? This was the problem when I saw same symptoms as yours after HG replacement.
OK, thanks for the input guys. Here's where I am now and I'm looking for further advice:
In the process of trying to override and force the fuel pump to run, both with putting a jumper in the pump check connector pictured above AND by putting a jumper into the connector for the Circuit Opening Relay (COR), I could NOT get the fuel pump to run (as evidence by sound and no pressure building at the banjo bolt for the cold start injector). I also even tried running a wire from the battery straight to the pump connector behind the fuel tank... no joy. So I decided to change the fuel pump. Upon pulling out the fuel pump, confirmed the old one would not run even hooked straight to battery but new one does. So that's a win. But I still can't get power to the fuel pump, so this is really frustrating. When we hotwired the new fuel pump to the battery, the engine starts momentarily but then dies. Today I changed out the COR with a new one AND tried a jumper in lieu of the relay with the new fuel pump installed. No joy. Can't hear the pump, no start.
Here's my summary:
Engine died on the road, got a six flash check engine light (indicating ignition system issue or ECU) with diagnostic plug jumpered
Checked spark at each spark plug boot with screwdriver arcing to valve cover, got spark from each boot
No pressure building at cold start injector, no noise, both jumper methods tried, no help
Changed fuel pump
Changed circuit opening relay (COR)
Tried bypassing COR, no help
Ran multi-tester at B and Fp ports on connector for COR, turned on key and after a strange cycle on the read-out, I only get .33 (1/3) volt or so
You didn't mention checking the fuses. Or continuity of the wires to the pump. I feel your frustration but, try not to guess and throw parts and money at it. Verify/test first.
Try not to jump around when troubleshooting. Start at the source or at the pump and work back. New pump works direct to a battery, why don't I have power to pump? Do I have continuity through pump wires? What puts power to the wires to the pump? The relay works or doesn't? Why?
Sorry, maybe you know this. But it's easy to assume something is ok and overlook it when you get a situation like this.
On a positive note, this is going to make you learn a LOT about your truck. Please post up whatever you find so it can help others. GOOD LUCK!
How and where did u bypass COR?
Measured V at "B" of test port with negativ probe to ground?
HOW COR WORKS HERE:
https://www.yotatech.com/forums/f116/how-circuit-opening-relay-works-22r-eliable-303166/#post52387681
Last edited by RAD4Runner; 05-08-2022 at 10:25 AM.
You didn't mention checking the fuses. Or continuity of the wires to the pump. I feel your frustration but, try not to guess and throw parts and money at it. Verify/test first.
Try not to jump around when troubleshooting. Start at the source or at the pump and work back. New pump works direct to a battery, why don't I have power to pump? Do I have continuity through pump wires? What puts power to the wires to the pump? The relay works or doesn't? Why?
Sorry, maybe you know this. But it's easy to assume something is ok and overlook it when you get a situation like this.
On a positive note, this is going to make you learn a LOT about your truck. Please post up whatever you find so it can help others. GOOD LUCK!
I did check all the fuses in the driver's kick panel area, all of them looked visually OK (no obvious breaks, no blackening, etc.). Maybe couldn't hurt just swapping them out with new?
I will look into how to check continuity, I have not done that before. But also, with the 6 flash code, the FSM says a few things it could be and since I've checked spark is good, it seems to be leaving the ECU as a likely culprit. Not cheap but within my skillset to swap it. Any other advise is much appreciated and welcomed.
I tried two methods that I had seen on the interwebs:
1. I used a jumper (paper clip) in the rectangular test fuel pump test connector by the driver's side fender under the hood. No joy.
2. I removed the COR and jumpered between the B and Fp locations (with the plug's clip facing downward, the bottom middle and bottom right positions).
I tried these methods in tandem and separately, neither made the fuel pump run. I now have a clear fuel filter spliced in place where I had to cut the frozen flared fitting out for the fuel pump output off the top of the tank. So when the pump is running there is also visual evidence now, when the access hatch is open, which it is.
I did not test the plug for the COR with the positive lead to B and the ground lead to the car's frame, I put the ground lead into Fp. So that was probably the wrong thing to do? I'll try connecting it to B and bare metal into the frame somewhere.
RAD4Runner is giving you some good info. ECM's don't fail that often. Although the mention of the leak possibly hitting it causes some concern.
You have to be careful and not rely entirely on a code. One example I can give is when a friend of mine had a 2nd gen 4Runner with a 3.0 start running a bit rough. So he did some work on it. New plugs, wires filters, etc. and gave it back to his wife to drive. She said it got worse and had a CEL. It had a few codes. According to the codes he had bad sensors, possible ECM and all were expensive. We both were techs at a Caterpillar dealer so not new to the game but, not Toyota experts either. So he tested the sensors and such. They tested good. No way he was going to spend the money when they tested ok. Messed with the truck for a couple weeks. It ended up being cheap aftermarket tune up parts. Mainly the plug wires that caused all this. Moral of the story is VERIFY before you replace. The CEL's are not always definitive. More of a starting point.
One thing at a time. You KNOW the pump isn't coming on. Find out why. The jumper wire is supposed to bypass other circuits so if you aren't getting power to the pump with the bypass jumper wire in place, start checking the wiring from the pump to the source. I hope you have a schematic.
I'm not saying the ECM isn't the problem. I would just hate to see you search for one, spend the money and find out it's not the problem. Got any friends that have an ECM you can try? I don't see a coil problem .....yet. You said you had spark.
So far......IF I understand you correctly, you can't get the new fuel pump to power up (direct to battery confirmed it worked though)
RAD4Runner is giving you some good info. ECM's don't fail that often. Although the mention of the leak possibly hitting it causes some concern.
You have to be careful and not rely entirely on a code. One example I can give is when a friend of mine had a 2nd gen 4Runner with a 3.0 start running a bit rough. So he did some work on it. New plugs, wires filters, etc. and gave it back to his wife to drive. She said it got worse and had a CEL. It had a few codes. According to the codes he had bad sensors, possible ECM and all were expensive. We both were techs at a Caterpillar dealer so not new to the game but, not Toyota experts either. So he tested the sensors and such. They tested good. No way he was going to spend the money when they tested ok. Messed with the truck for a couple weeks. It ended up being cheap aftermarket tune up parts. Mainly the plug wires that caused all this. Moral of the story is VERIFY before you replace. The CEL's are not always definitive. More of a starting point.
One thing at a time. You KNOW the pump isn't coming on. Find out why. The jumper wire is supposed to bypass other circuits so if you aren't getting power to the pump with the bypass jumper wire in place, start checking the wiring from the pump to the source. I hope you have a schematic.
I'm not saying the ECM isn't the problem. I would just hate to see you search for one, spend the money and find out it's not the problem. Got any friends that have an ECM you can try? I don't see a coil problem .....yet. You said you had spark.
So far......IF I understand you correctly, you can't get the new fuel pump to power up (direct to battery confirmed it worked though)
You HAVE spark.
It won't run.
This is good advice, thank you. For me, the issue is that I'm short on both money and time, but I'm shorter on time. I would be more content to spend a few hundred more dollars replacing targeted parts over gambling a couple days (I work slow, I'm not experienced at this stuff) that still ends up with spending $200-300 in parts. Tearing everything apart to chase a break somewhere is above my experience level and my amount of time I have to spend on this thing. I'm not saying that the ECM is definitely bad, but when the pump is hot wired, the truck starts and runs a few seconds then dies. Over and over. Before the fuel pump change, it wouldn't even start, just crank.
I did find the same part number ECM on eBay for $80 plus nominal shipping.
Speaking of ECMs... a guy I met locally is willing to give me a ECM from a 1993 pickup (89661-35810), free. My original is a 89661-35070. It looks like his has 2 plugs while mine has 3, I don't think it will work. Does anybody know what other variants should work with mine if I can try one? A friend has a 87 4WD w/auto transmission (mine is a 5-speed) and he's willing to let me try it but I'd rather save the tear-out time, postage and transit time if somebody in the know says it DEFINITELY WON'T work.
I totally understand your logic. I'm just the opposite. Lots of time and little money.
Check out the Toyota Bible on Pirate 4x4 forum. I thought they had a list of ECM's and what would interchange. Might even be available on here somewhere or Marlin Crawler. I know I saw one somewhere. For $80, I'd probably get that ECM coming anyway. It's getting harder to find stuff for these older trucks and it's good to have spares.
I hope you get that nice truck of yours running. Off topic but the first new vehicle my wife and I ever bought was an 86 4Runner. Had over 450K miles on it when our kid totaled it. A friend put the engine and auto trans in another truck and ran it I don't know how long. So we have a soft spot for the 1st gen runners.
HEY! I just thought of something. My current build is an 86 Xtra cab with a 22RE and 5 speed. I'm running a 3.4. I sold the engine and trans but, I MIGHT have the ECM. I'll go look right now.
The ECU WILL NEVER prevent the fuel pump from coming on.
Do you even hear the COR click when u try to crank?
Thank you RAD4Runner for you info so far. I have some updates on the exploration so far:
- A friend brought a friend over while I was gone and did some electric testing. They found that there is a short somewhere that had caused the EFI relay to stay closed and then fail. He replaced the EFI relay then it promptly started blowing a fuse (I think the EFI fuse, would make sense, but I don't remember for certain).
- They could get the truck to start for a few seconds and then it would die, when providing the fuel pump dedicated power and jumping the EFI relay
- They also found a faulty/loose connection at the cold start injector and when one of them would jiggle it while cranking it would start
It has been suggested to provide power to the fuel pump off of a add-a-circuit adapter from a fuse socket that is hot when the key is on because chasing down this short right now is above my expertise and allowance for time.
It has also been suggested to pull the EFI relay and put in a switch in my panel instead. But I don't understand how that would function any better than just jumping and bypassing. When would I want the switch ON? Would I ever turn it OFF? Why a switch?
One of my limitations is that everybody else has a life to live so I'm getting little bits of help when I can get it from several places and I, as the common denominator, am no expert at any of this so I'm piecemealing it all together hoping to stumble upon the solution.
Thanks in advance if you have a moment to chime in again.
Sounds like how mine acted when my fuel pump died. Mine was running great, stopped and went into store, drove away fine. Then within a few miles was losing power and jerking. Then it died. It would crank but not start.They can die for no apparent reason. Had to have it towed home. New fuel pump and good to go.
I had been hoping at one point this was going to be the case, but it turns out that the fuel pump WAS bad but it was/is not getting reliable power. The search continues.
11-27-2021, 03:44 PM
Need Help Diagnosing: 22RE Ignition or ECU failure, other? 86 4Runner Dead w/Code
