I was having cold idle issues but after changing the 02 sensor and the air pressure sensor the cold idle is great but........

I was letting the motor idle while it was warming up. After maybe 5 minutes, the idle went from great to stalled within 5 secs. It stalled out so fast it was like the fuel pump had just failed but it started right back up but still would not idle.

After I let the motor sit for a couple of hours, it started right up, idled great until it again stalled after about 5 minutes.

Its not overheating btw.

Before I get flamed, I did try to search for this problem.

 

It's happening to me right now - sounds like the same thing. 5 minutes, it just gets warmed up and is getting down to it's proper idle, and it's like you shut the key off (but the ignition isn't shutting down).

You can't restart it right away either? You have to let it cool back down?

I've tried all sorts of things and most people point towards the coolant temp sensor, the TPS, or vacuum leaks.

I've tried swapping to another TPS, a different ECU, a different AFM, unplugging the temp sensor after I start it, etc. I can't find any vac leaks, and haven't been able to figure out what the issue is.

I'm trailering the car tomorrow morning to a mechanic who is quite knowledgeable on rotaries to see if he can figure it out.

Once he does, I'll post it here and try to send you a PM.

If you figure out what it is, let me know.


Thanks

Grant

 

After the cold idle cycle has finished, does it try to idle at 500rpm or something else too low? Pay attention to the tach next time, so you can be sure whether it's dying at something reasonable like 750+ RPM, or not. If it's stalling because the idle drops too low, open your air bypass screw.

 

I've played with the idle while trouble-shooting it but before I touched it, the RPM would be about 1K when it died. When I messed with it, I got it idling about 750 before it quit.

Grant

 

how many miles is on the motors?

 

check your idle air control valve

 

Mine has about 15 hours on it.

 

I think mine might be the BAC. The original one I had was stuck shut/open so I bought another one (used). The idle air screw is turned almost all the way in. It was about 1 full turn from being seated. But it doesn't seem to make a difference to the idle if I turn it out. I turned it out until it was about flush with the housing but the idle did not improve.

Does anybody know how many turns out the screw should be set. At least for a starting point.

 

sounds like vac leak.. cold start assist is masking the issue when cold