hi all, got this idle problem, was hoping to check if im looking for the problem in the right direction and if anyone got any suggestions.

its a civic 96 ex with d16y8 manual.
car was running fine, till randomly one day it changed.

symptom: cold starting the car, it would idle at around 1.5k then gradually drop to around 800 as it warms up.
after it kinda warms up it, idle will drop to zero or atleast on the cluster, making the car bog down, engine kinda works at the point of stalling.
and just stalls. only a few times it held a steady idle for a very short while.
car drives fine, but im blipping the throttle for it not to stall when in neutral or with clutch in.

cleaned the iacv a few times, mesh is kinda broken.

vacuum leaks?
halp!

 

CEL codes?

 

there is no codes

 

How did you check?

 

It is designed to run around 1500 right after a cold start then slow down as it warms up.

Vacuum leaks will make it run faster than normal. The MAP system simply sees the manifold pressure rise and adds more fuel to meet the extra air. This is unlike other cars which are MAF controlled, those will idle poorly or stall when there is an air leak after the meter.

Test your TPS with a voltmeter.

The two wire IACV such as yours is pretty easy to set up. Warm up engine, turn all accessories off, and unplug the IACV. Observe idle drop, but it should not stall. Set the air screw for less than normal idle. It should pick up normal idle when you re-plug it. Unplugging IACV will turn the CEL on and throw a code, this is a good way to confirm that the CEL and code storage works.

 

i'm checking CEL codes with an ultraguage. not sure if there might be any other information from the ultraguage that could be usefull.

tried unplugging the iacv after warm up once, but the car doesnt even hold idle after warm up to let me check. so it would stall.
but it did turn on the CEL.

will check the TPS then when i get a chance.

 

Also test the ECT sensor, and then try adjusting the idle speed (see FAQs sticky).

 

little update.
didnt have time to measure TPS/ECT sensors but, tried resetting ecu, and later got CEL codes instead.
P0301-P0303-P1300

i guess will to look into that

 

Do a full ignition system tune up.