Idle problem 4g93

stomfire576

New Member
Hello All,
My 2001 1.8 auto (128000 klms) has an idle problem. Engine stalls when backing off for corners or stopping in traffic. I adjusted the cable tension to increase the idle and that worked for a while, until problem started again. I have replaced the tappet cover gasket kit and changed leads/coil packs. (Spark plugs replaced recently). This seemed to fix the problem and had to then lower the idle speed back to normal. Today was running a bit rough (sounded like it had different exhaust), stalling started again so idle is back up again. Checked plug leads no oil leaks. Any idea's?
 
Change fuel filter, clean MAF and throttle body would be a few more things to try.
 
Hey mate, 100% look into changing the Idle Air Control Valve - I had the same issue, was extremely frustrating having the car stall every time at idle making stopping at lights and parking a nightmare. I changed a bunch of stuff like the coil packs and leads etc but what finally fixed it was replacing the IACV. 4G93 Ce Lancer
 
Cleaned the throttle body today and it was pretty dirty . IACV port was grubby too. Made a new gasket as no one seems to sell them and will try again tomorrow. If idle still bad will replace the IACV solenoid but they seem to be around $140. It may have been getting stuck. Why does coolant run through the throttle body?
 
Cleaned the throttle body today and it was pretty dirty . IACV port was grubby too. Made a new gasket as no one seems to sell them and will try again tomorrow. If idle still bad will replace the IACV solenoid but they seem to be around $140. It may have been getting stuck. Why does coolant run through the throttle body?

The coolant is for a couple of reasons;
- to prevent the butterfly valve from sticking to the body
- to speed up the warmup of the car/warm up the incoming air/keep the incoming air at a temp range for economy and emissions.


It can be bypassed with any length of suitable hose directly back to the block if you feel so inclined. As for the idle problem, disconnect the battery for 10 minutes and try to cycle the ignition to discharge any leftover power. Wait, then reconnect the battery, and start the car and let it idle for at least 16minutes (yes 16minutes - the car runs on cycles of 4minutes). Your ECU might be trimming fuel incorrectly and causing the funky idle, so a restart of the ecu via power disconnect will let it relearn itself. 4 lots of 4mins at idle will cover the basics, and then 4x 4mins of cruising at a constant speed should cover the cruising/driving conditions.

All of that is assuming the ECU is a bit iffy with idle.
 
Finally got the $200 ebay ISCV yesterday. All good so far. Seems to be running pretty smooth with all the other stuff replaced/cleaned/reset in the process.
 
Did you give the throttle cable a little bit of slackness to allow the throttle plate to close and the TPS to read idle properly. The idle speed can be adjusted with the idle speed screw on top of the throttle body sometimes under a rubber bung.
 
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