pcguy760

My turbo H22A Civic was fine until suddenly it just started dying or idling very low (less than 400 rpms) only when I come to a stop. While I am driving it runs great without any hiccups - only when I stop (ie. a stop light, etc.) it does this or if I just hit the clutch in it wants to die on me.

Any ideas what can cause this? AF ratio and Vaccum readings are all great and more or less the same they were last summer btw and the bov is correctly adjusted so it does not affect the idle...

EL Vap133

Valves maybe? No CEL's by chance?

del sol 1443

I am having the same problem with my B16A2.... runs great till you come to stop push in on the clutch and let the tack drop.... idles fine till it warms up and you drive it then it starts playing the dieing game... mine like to bounce when it idles after it has started this... it has me stumped....almost seems like a vacuum problem but I can't find anything...lmk if you find something

Former User

Dirty or bad IACV?

delsolproblems

The idle speed is increased by the IACV based on the demands of the engine, including when the ECU expects an upcoming demand in some cases. This is why all of our cars should idle a little higher before the car comes to a complete stop, when the clutch is depressed, when the lights are on, etc. If your car dies at a stop but runs great at higher RPM's and the idle screw has not been adjusted (since the car ran fine), then you either have a vacuum leak, a faulty FPR, dirty TB, or a problem with your MAP sensor (i.e. an AFR problem). A TPS problem is possible but highly unlikely if it hasn't been messed with. Check the MAP sensor voltage at idle and higher RPM's and post your findings. Check/clean inside the TB and check/change/clean your air filter.

del sol 1443

ok that sounds good will do and see what I find....

Former User

Vacuum leaks cause a high idle, which is not your problem. For a low idle, you should generally start by cleaning and checking the IACV.

delsolproblems

Anything that throws off the AFR can cause a low idle. Too little vacuum can make the motor run rich and have trouble at idle since that is when the least air gets in and when the difference between what the vacuum is and what it's supposed to be are the greatest.

Former User

I think you mean air intake rather than vacuum. This would be a rather uncommon cause for a low idle, unless dictated by CEL codes that have not yet been mentioned. More frequently, low idle is associated with a IACV problem.

delsolproblems

No, i mean intake manifold pressure. Try disconnecting a vacuum hose at idle and see if the motor revs or dies. A small vacuum leak won't necessarily cause a CEL. I totally agree that checking the IACV is a good idea.

pcguy760

Ok, thanks guys - I will do the following let you know what's the outcome...

1. Clean IACV
2. Check / Change MAP Sensor (I have about 3 working ones)
3. Clean TB

BTW, there is no vacuum leak according to my boost gauge - it stays in the same position at idle for the past few years or so. I also disconnected a vacuum hose and it idled high so that is probably fine I guess...

pcguy760

NO CEL's or codes and what makes u think it might be the valves? Just wondering...