Similar thing was happening to a coworker of mine, on a totally different car of course. When we talked about it, I suggested they look at the ECU. His mechanic said it was either going to be the ECU or the crank sensor. They replaced both and the problem went away, go figure. I still thought the ECU was the main culprit and I wouldn't be surprised if that is the case here.

Not sure if the crank position sensor would completely kill the engine like that, but a bad ECU will.

 

Thanks for the input! I got the ECM in today and so far so good. But I will report back later this week when I get it more time with the ECM in the car.

 

Well the problem is still there. Both the temporary stall and start back up and the complete stall and won't start until I cycle te keys. It isn't as consistent as it was before but it is getting worse. Something I noticed today that I didn't notice any other days:

I rolled to the front of my house in neutral, pulled the ebrake, and went to turn off the car and it just shut off. The green immobilizer light blinked about 6 or 7 times and then went out. What I noticed that was different was that as soon as the engine died the CEL went out and never came back on. I also noticed that I could not hear the main relay click.After this I pushed in the clutch and tried the start button, she wouldn't start. I had to turn the key off and then back to the on position and I was able to start the car again.

What does it mean when the CEL light never comes on?

Info that I didn't disclose before was that my car does have a CEL for a bad o2 sensor (secondary). I didn't mention this before because I didn't want people to focus on this as an issue because I know it isn't. I recently replace the o2 and it still did both problems with a good o2. The reason it is bad again is because the cat had broken loose and was smashing the o2 sensor tip. I have since replace the cat with a Invidia 70mm with CEL fix. I have a new o2 to go in but I'm in the process of moving.

Again, any idea as to why the CEL goes out and does not come back on until I cycle the keys to off and back on again?

 

Well damn, can't comment on the cel thing. I would look into the ignition tumbler as mentioned before.

 

It's already been looked into Wiring an all.

 

I'm going to try some voltage testing this weekend for weak grounds and things and if I can't find anything I'm going to take it to the shop. I'll get back to you with updates

 

Just a few more ideas:

- have you tried all Honda forums, not just s2000 ones? I'm sure the platform for the immobilizer, ignition and all the wiring is close to the exact same if not exactly the same.

- have you tried just pulling the key out while driving, Just to see if results are similar. Closed road of course.

- I wonder if a shop with a nice "real time" diagnostics tool could pick up anything like "immobilizer triggered" if they got the car to act up while hooked to the diagnostics tool. You may get a little more insight as to what's actually happening during the shutdown process.

- Have you taken the cluster off and looked at connections there? I'm sure that a relay is triggered to actually shut off the immobilizer, but what tells the light to come on..,.ecm, and in what order??

And a suggestion. If you're have to measure voltages or ohms on pins, like the ones on the ECM, get some gator clips from radio shack. They'll make it much easier. Possibly recruit a friend to shake and bend wires.

Wish I had more for you. Good luck with it all.

 

Have you actually tried removing the immobilizer from the wiring going to the starter? This would at least answer rather or not your immobilizer was being triggered.

My sister's van had an aftermarket immobilizer that was getting triggered by a faulty fob, so I just removed the immobilizer completely from the wiring and tossed the fob and the receiver.

 

Also, you said that you've familiarized yourself with the wiring, does it have a relay to on/off the immobilizer? If so I'd replace that.

 

Well the immobilizer receiver has been replaced as has the ECM. Essentially the immobilizer system has been replace minus the harness. So the immobilizer is not likely the issue. Based on the fact that after I replaced the ECM I was able to drive the car over 200 miles, both normal and hard driven and not have the problem. I'm thinking that something may be causing the ECM to go bad. However I will try to rule this out as I have a friend with an AP1 that will hopefully put this ECM in his car and ride around with it. If he doesn't experience the same symptoms then it is not the ECM.

I plan to voltage test the grounds this Sunday to see if they're all acting properly. Just so everyone knows you can get to the g101 ground with the valve cover off, it just takes patients.

I am also going to schedule the car to be looked at by a shop on Monday if I am not able to find anything conclusive.

I'm really low of available work time on the car given my work and life schedule lately and I would really lien this problem fixed as it has made the car so much less enjoyable to drive. I will report bad any findings for future reference as I have so far. And I really really appreciate the information and suggestions provided so far.

As far as the cluster goes, I do not believe it to be an issue at all given that the CEL light is only out after the car cuts off completely until I cycle the keys to acc and back to on then it comes back on again. As it's supposed to when you turn the key to on.

I has done additional research not related to the s2000 and none of it has revealed any solid information that I have not already tried or is not related to my issue.

I'll see if I can get around to working on it tomorrow if it isn't raining here. If I can I'll report back right away with my findings.

Again thanks for the help thus far, it's been much appreciated!!