windhund116

I agree. You want to do proper measurements when rebuilding the bottom end. Endless you are only going to keep the car for a short period of time. I dunno... I'd prolly shoot myself, if I went to gyrations to change the thrust bearings with the engine in the car, only to have the main bearings die --- a year later. But, that's just me.

ElRod

Did you ever fix this issue? I Have an 00 AP1 and have a similar problem, the car stall when decelerating if I leave the clutch pedal pressed/or for too long
(It does not happen if I quickly let go of the clutch, I know that is how it should be driven however, it does not take away from the fact that this is not normal).
I have already replaced sparkplugs, MAP sensor, IACV, and clutch master cylinder with little to no improvement to this issue.

windhund116

Have you done an oil analysis?

Chuck S

@WayneYoung hasn't been here for 2-1/2 years so maybe this tag will wake him up.

Oil analysis will be helpful though. Blackstone Labs will send you the sample bottle and mailing kit for free. You'll pay $35 for the report which will compare your metal and oil wear content to their data base of S2000 engines. They highlight abnormal wear.

-- Chuck

engifineer

I am doubting this is due to the thrust bearings, which would be the cause you would be looking for here by doing an oil analysis. Thrust bearing issue typically will stop the motor dead in its tracks when depressing the clutch. Sounds like his is stumbling and dying? I mean, oil analysis is always a good idea to see the health of the engine, so not saying not to do it.

After doing the other work, I assume during which you had the battery disconnected, have you performed the proper idle relearn procedure per the shop manual? Mine was stubborn once after some work and until I did that process completely, it would also stumble and die when I pressed the clutch, unless I blipped the throttle to keep it running. I re-did the idle relearn and it fixed the issue. Maybe the IACV was your issue but if you disconnected the battery while working on it and did not perform this, you are seeing it for a different reason now. Worth trying it to see.

Also, any mods? Running a tune or anything?

Car Analogy

The idle relearn topic also has me thinking, not only can battery disconnected require relearn, but iacv clean in and of itself could require it.

Iacv slowly gets dirty over time, and ecu slowly keeps up with compensating. Then all of a sudden iacv is vastly different from being cleaned, while ecu still thinks its dirty.

ElRod

I have yet to do an oil analysis but I will look into it, I did indeed do the idle relearn procedure following DIYguys video instructions with improvements to the idle but not the issue. I had the car for a lil over a year now and I have barely driven it just as a preventive measure in case this issue can damage the engine. That being said I do not have a lot of background on the car, the previous owner did mention that he installed a new stage 2 clutch but he is not a car guy so he is not able to tell me what components were used (eg. flywheel, pressure plate, etc.) in fact the car was also parked outside for 2+ years since he has been overseas, and that is about all the background I have on the car, it has never been modded/raced as far as I can tell everything is OEM (virgin with all VINS). I changed all the fluids, air filters, and missing hose clamps. The car does have a clutch buzz (normal on AP1s?) and I have yet to do the rear axel adjustment, other than that the engine sounds good, has no CEL, and is steady idle (800-1000). One thing to note is that MAP sensors and IACV were from eBay they are DENSO( I still have the OEM, I'm just trying to narrow down the possible causes until I find the culprit). And yes it stumbles/stalls when the clutch is pressed when deaccelerating, essentially the revs go below the idle point all the way to zero and it dies (only if I don't shift fast or let go of the clutch) , I have to always shift like I am racing which is fun but not when I am trying to cruise, in traffic or just obeying the law.

B serious

Unknown stage 2 clutch....

You might have thrust bearing issues, or the issue may be related to the clutch or clutch release bearing.

Have someone knowledgeable check the car. But don't just keep driving it.

windhund116

Engine dying when clutch is pushed in....

latelifecrisis

Plus he states it happens when engine is warm (thermal expansion causing thrust washers to bind). This was my exact scenario. Definitely wouldn't drive this car more until cause is determined.
I'd drop oil pan and have a look. A previous poster was able to carefully verify washers were correctly installed without removing the bottom girdle.