Regarding idle problem.

**speed unlimited** · August 27th, 2009 10:27 PM

Just want to help other tsikot member as i observed on the forum most of the problem ask is regarding idle . There a lot of thread regarding this mater .I dont know if there is one here . There must be someone to have it sticky so that those who want to ask about this will have there idea regarding this problem. They might read it first before they ask Questions about there idle problem issue. THANKS.

**speed unlimited** · August 28th, 2009 08:58 AM

HOW TO : BAD IDLE TROUBLESHOOTING.
I noticed a decent amount of people here have idle problems, so I have typed up the FSM trouble diagnostics for an unstable idle. Enjoy:

1. Check EGR control valve for sticking (stick your hand under it and see if its stuck).
2. Perform power balance test: When disconnecting each injector harness connector one at a time, is there any cylinder which does not produce a momentary engine speed drop? If not, go to step 6.
3. Check Injector: Remove distributor from engine (crank angle sensor harness connector should remain connected). Disconnect ignition wires. Turn ignition switch ON. (Do not start engine). When rotating distributor shaft slowly by hand, does each injector make a n operating sound?
4. Check Ignition spark: Disconnect ignition wire from spark plug. Connect a known good spark plug to the ignition wire. Place end of spark plug against a suitable ground and crank engine. Check for spark. If no spark, check your coil, power transistor, and their circuits.
5. Check Spark plugs: Remove the spark plugs and check for fouling, etc.
6. Check Fuel pressure: Release fuel pressure to zero (pull fuel pump fuse and let engine die). Install fuel pressure gauge and check fuel pressure (at idle, it should be about 36 psi).
7. Check O2 sensor: Set “Exhaust gas sensor monitor” in the self diagnostic mode II. Maintaining engine at 2,000 rpms under no load, check to make sure that the red led on the ECU or the check engine light goes on and off more tan 5 times during 10 seconds.
8. Check for Intake air leak: When pinching blow-by hose, does the engine speed rise? If so, search for a leak.
9. Check idle adj. Screw for clogging: Disconnect TPS harness. Can you set engine rpm at 750 plus or minus 50 rpms by turning the screw? If not, check for a clog.
10. Do a compression check.

One thing this left out is checking the IAA. I would defiantly try that too if you are having idle issues. To check it, disconnect the AAC valve harness. If your engine speed does not drop, you may have a problem with your AAC valve.

I hope this helps you guys

**oj88** · August 28th, 2009 06:53 PM

Most of the steps indicated in the article are SR20-specific. Troubleshooting engine idle problems especially on modern cars, is a bit more particular. This is especially true when running diagnostics on the ECM/PCM... each manufacturer will have their own set of procedures.

**speed unlimited** · August 28th, 2009 08:34 PM

Originally Posted by oj88

Most of the steps indicated in the article are SR20-specific. Troubleshooting engine idle problems especially on modern cars, is a bit more particular. This is especially true when running diagnostics on the ECM/PCM... each manufacturer will have their own set of procedures.

This is just an idea to those who have encounter this problem .If you have something to share regarding this matter please post . Theres a lot of tsikot member asking about how to solve there idling problem. THANKS. Just remind this open to all for suggestion to help other member to solve the problem.

**bambino** · August 28th, 2009 10:24 PM

when it comes to idle problems ,especially for the mechanics who want to learn more about DRIVEABILITY DIAGNOSTICS , i suggest them to get a proper training to understand more of the modern vehicles these days .

and for the car owners are no mechanics ,leave it to the pros or you can only try checking the basics.

even those seasoned techs when it comes to driveability diagnostics they always want to wash their hands and walk away .

basics ;
spark - at least 25kv
fuel pressure -it depends on the manufacturer
vacuum leaks - use air hose to detect where's the hissing sound
mechanical timing- go with the book

if any codes present - go with the pros .

**koozzy** · October 15th, 2009 06:32 PM

Sir Speed,

What id the idle is too high (2Krpm) when parked and idling goes up and down even when driving.. what could be the issue?

My car just got submerged on the floods recently.

cheers,
koozzy