1997 4runner will run for 6 minutes then shut off, changed the ECM now it runs 2 sec the shuts off

Let it sit with a dead batty for a month then replaced battery. It would run until it started getting warm about 6 minutes then shut off. wait a day same thing, next day same. It would run perfect for about 6 minutes then cut itself off. No sputtering, no hesitating just off. It has gas. Replaced the ICM with a used one, No change. Run 6 minutes then shut off,

Replaced the ECM with a used one, then it will start and run for 2 seconds then shut off. Reinstalled my old ECM, now it will start and only run for 2 seconds. Installed a different ECM (3rd one) and now SAME story.

It will start and run for 2 seconds then turn itself off.

I've searched a lot of FORUMS and have not seen this problem. Any knowledgeable person out there know what I should do?


Thanks in advance,

 

Check all power and grounds to the ECM. Look for bad wiring.

Any engine codes?

For the ECM to shutoff the engine like that, I'd almost suspect the ECM loses communication with the cam or crank sensors. But then I'd also suspect a hard start. But maybe it's just a bit of vibration 2 sec after startup that causes a short?

How do you know it has fuel? Maybe the fuel regulator or pump is failing? Did you do a fuel pressure test?

One way out idea:
Check your ignition switch. Put some pressure to hold the key away from the off position. Had a car that the ignition switch was so sloppy it would turn off the car.

 

Someday this is going to help somebody...lol

 

Are you certain that your battery is fully charged, that the alternator is charging the battery properly (worn brushes), and that there’s no parasitic drain going on?

 

If it is that...then I'd try replacing the COR which I'm pretty sure that Green Wire with Yellow Stripe is attached to.

 

Interesting. Reading up on the COR I think you may be quite right. I was always under the impression it was an ECU issue

 

I "reinstalled" my old ECM after the third EMC that also shut the engine off after running 2 seconds and my "old EMC" will let the engine run until the engine gets warm just like before. So, after replacing the ICM and trying other ECM nothing has changed. ""It runs until it warms up about 6 minutes"". I love the 4Runner for the past 27 years. Any help would be GREATLY appreciated.

 

What have you tried besides swapping ECMs? Remember, this whole thing started with a dead battery.

How many miles on this alternator? If 150k or more, have you ever replaced the brushes?

Have you checked for a parasitic drain?

 

Replaced the battery with a brand new one, have at times kept a battery tender on it after repeat starts of 2-second runs, but not after the 6-minute runs at various rpms, replaced the ICM, added a ground wire to metal frame on ECM, checked ohms, on coils, and plug wires, checked plug gap while inspecting for oil in plug socket hole, It has run about 12 times until it gets warm then shuts itself off. It will NOT restart until it cools off completely even with starter fluid. It starts immediately when cool, no spudder, no miss, no hesitation, runs perfect-----until it gets warm; not 'hot' just warm. Can drive it down the road until it gets warm.

 

I dunno. Me personally, I would attempt to rule out the charging system. If a brush in the alternator is near failure, it can cause odd problems. If you haven't looked at those and have a lot of miles on the alternator, they should be replaced regardless, or at least looked at.

Perhaps something comes on or a relay energizes at warmup that places an extra demand on the charging system, resulting in the symptoms you're experiencing. I may not be on the track at all, but I've read about so many weird things being related to the charging system. For example, your original ECM displayed the 6-minute symptom and the 2-second symptom, if I understood correctly.

Also, has anyone asked about aftermarket items such as remote start? I had a major struggle with that on a Corolla once.

 

Daddykool, it has the original alternator. May replace it today if it stops raining. The original EMC runs 6-minutes, the replacements run 2-seconds {maybe I did not have them grounded good enough}. So, I reinstalled the original EMC.

Perhaps you are right a relay that comes on when warm is "turning OFF the engine". Or may be a solenoid in the transmission that would allow it to shift when the temperature reaches a certain degree. "WOW" now a new search!!!!!

Does anybody know what relay or how many relays switch when the engine gets warm? Don't forget the engine runs great until it gets warm then shuts itself off.

 

Sounds good. FYI, concerning the alternator, it almost never fails as a unit. In my experience, it has always been worn brushes. If you're in no rush regarding that, you can get a replacement brush assembly for $15-20 from an online dealership or Amazon. Installing it is a breeze if you already have the alternator in your hand. They all pretty much look like this. Held on by two screws. If you're thinking about replacing the alternator anyway, take it out ahead of time and remove this assembly. The brushes are inside, and should look something like this pic. If one of them is black (or both), it's bad.

https://www.youtube.com/watch?v=ijnef02gPK4&pp=ygUhcmVwbGFjZSBhbHRlcm5hdG9yIGJydXNoZXMgdG95b3Rh

https://www.youtube.com/watch?v=K2jqGTHFilg&pp=ygUhcmVwbGFjZSBhbHRlcm5hdG9yIGJydXNoZXMgdG95b3Rh

 

Did you replace the COR? or try grounding it like in that thread?

I would be looking at the fuel pump circuit. I'm betting it's getting shut off. I wish I knew if the ECU had logic to do that and what it uses to make that decision.

 

If it was the alternator the battery dummy light would come on before it shuts off, I would think.

 

Yeah, normally. With this being the original alternator, the brushes are probably shot. He could be experiencing intermittent undervolt or undercurrent conditions. Doesn’t hurt to make sure your supply is solid.

 

The transmission shop said no on the solenoids, but to try restarting it in neutral.

Will pull the alternator this afternoon.

Would still like to know what people think of a relay turning the engine of at warm.

 

Maybe the circuit opening relay?

 

Good idea. Any idea of which relays opening when warm that I can test? You had posted an earlier post with a page of a wiring diagram showing some open relays. Where can I get a complete wiring diagram? I've tried several places online.

 

You want to find the service manual.

https://drive.google.com/file/d/0B4...en&pli=1&resourcekey=0-AeWhnlEHWNLpTf_ZldgUAw

Got to page 2000 or around there.

It may be slightly different for 97 but it's very close.