I've been noticing a problem lately where I'm driving my car enough so its fully warmed up, I park and shut it off, then a short while later when I restart the idle is low, and drops and the car wants to stall if I don't give it gas. This goes away after a minute or so, and it doesn't happen if the car isn't warmed up already. Any ideas?

I had idle issues on cold start before when my air pump died. I thought replacing that would take care of all of these problems, but it only helped the cold start idle.

Any ideas?

Thanks,
jds

 

bump!

 

get a compression test done or do it yourself. Trouble idling or starting when warm is a notorious problem for low compression motors.

 

I would have guessed heatsoaking of the starter (then I realized that this isn't a GM), until you mentioned that you have to give it gas to keep it going. Yes, do a compression test.

 

Ugh, that's not the answer I was hoping for! :-(

For what its worth, this condition only lasts a minute or two, and there's never a problem starting, just keeping it from stalling. Ugh. Compression test

 

If its only temporary its probably something else then. Didn't mean to scare ya Not sure what it would be though, maybe one of the experts will chime in.

 

I use to have a similiar problem, for me it was that the engine would partially flood making it really hard to start up. That was my problem not sure if that's yours just a suggestion.

 

My ex ('87 T2) used to flood easily on warm start, but in that case it just flat out wouldn't start. I suppose it could be a similar case with slightly different symptoms, but there is never any problem with it starting. Even if I stall it it starts right up again.

jds

 

I have the same problem even though I got new rotors and housings. I do not think it is a compression problem.

 

What ems you running? I have a PowerFC and have them same problem - though not as extreme. It starts fine when warm but runs like crap up to a little below operating temperature. I have never gone through my settings with the datalogit for this but I suspect there are some temperature related settings that can adjust this. It is on the "to do list" but far down.

Shawn

 

I'm on the stock ECU right now until I can get my Pettit ECU fixed.

jds

 

I was searching for something else, unrelated to this thread, when I came across this hot start problem that I used to have back in my FD days

Mazda, in their infinite wisdom, put an actuator inline of the vacuum hose going to the fuel pressure regulator. When under hood temperature reaches a certain level during a warm restart the actuator cuts off vacuum going to the FPR which raises the fuel pressure at least 10 psi. I had the same exact problem with my FD, and sure enough every time it would do it I would see the elevated fuel pressure on my Defi gauge....as soon as the pressure went back to normal the idle would too. The best part of all this is that I think Mazda worked this control feature into the ECU to help warm starting! I hope this helps.

 

Oh and I forgot to mention...if you never want it to do it, you can just bypass the actuator and run the vacuum hose straight to the FPR.

 

Pressure Regulator Control solenoid if I'm not mistaken. If anything this should help the car during warm starts.

 

sometimes if you have removed the AWS hose it happens. if you have a greddy elbow then it's probably off.