idle problem on ka24det (1997)

[tony/ka24de]

my car idles fine most of the time. But sometimes when I get to high rpm(4-6 thousand) I presss the clutch down to put it in neutral and as it comes down the car will stall out. Also when I start the car it seems like it want to die out, but then idle goes to normal. Anyone know what that could be.

[C-Kwik]

Check for a boost leak. Are you running an open BOV?

[tony/ka24de]

yes.

[95_240sx]

Theres your problem. Your probably running a MAF and you need to route the blow off valve exhaust back into the intake AFTER the MAF. Whats happening is your MAF is account for X amount of air, and gives it fuel for X amount of air, and when you blow it off to the atmosphere you your taking away part of the air the MAF accounted for, and gave the engine fuel for, so it turns SUPER rich when your BOV exhausts out. Your other option is to run a MAP sensor with a stand alone, personally I like mine.

Rick

[Justice]

The open BOV is venting air to atmosphere that the engine thinks its going to combust. its adding fuel to the air that the maf said was there, there for it gets realy rich and wants to die. its normal. hehe deal with it or recirculate it .

=)

[95_240sx]

Yeah, thats another way of saying it.

Rick

[tony/ka24de]

thats not the reason why its stalling, the rpms are coming down too fast. Before i put the turbo i had the problem, but it would not stall out. It would come very close and then pull up. There has to be somthing on out engines that act as a choke to control how fast the rpms drop. Its not the idle control motor, check that. And bumping up my idle does not work either.

[TurboKA37]

put it in gear faster so u dont let the RPMs drop

[tony/ka24de]

or i can fix the problem the right way

[TurboKA37]

there is no problem if u do it my way

[C-Kwik]

thats not the reason why its stalling, the rpms are coming down too fast. Before i put the turbo i had the problem, but it would not stall out. It would come very close and then pull up. There has to be somthing on out engines that act as a choke to control how fast the rpms drop. Its not the idle control motor, check that. And bumping up my idle does not work either.

Even if it sort of did this before the open BOV is likely going to add to it. And I doubt fixing the existing problem will help. Anytime my BOV recirculation tube fell off, it stalled when I came off of boost. Try recirculating it and see if the problem goes away. As far as the existing problem, try cleaing out your idle air control valve.

[tony/ka24de]

I fixed the problem, I don't think its the right way but it works very well and I don't recurculate the air from the bov. I adjusted the set screw for the throttle plate a bit higher. Works really good. The car idles at 850-900 rpm.

[klattr1]

usually you have to make sure your TPS(throttle position sensor) is inserted correctly like Nissan would do.You have to get car to operating temp and then set idle at 800 rpm while TPS is unplugged and then plug the TPS back in and turn off the car and then start it up again. If you still have problems, try this way out!

[klattr1]

u said your car is running fine now. I am sure it runs fine when you start it cold but does it run ok and idle fine after about 30 min when the ECU changes maps since the motor is warmed up?If it doesnt run right when the motor is warmed up, turn the screw(Idle Air control valve IACV OR IAA) behind the intake manifold near the firewall. Make sure and do it when the motor is warmed up and when u are having the idle problem. Report results

[tony/ka24de]

it runs fine when its warmed up to for now. since i adjusted the throttle plate its only stalled twice. But before then it stalled every time. And when I started the car the idle would drop and then pull up to idle. Now that problem is solved completely

[Dattebayo]

Really these idle things are a pain in the a$$. You could have bad iac/aac or maybe your oxygen sensor is going too. That used to happen on mine, and O2's are cheap so you can replace it and not hate yourself if it isnt the problem. Pull your plugs and see how you are running.

[tony/ka24de]

what colour should the plugs be?

[TurboKA37]

not black or have any debris built up on them