very high idle

jeffast · #1 11-08-2007, 12:40 AM

ok so ever since i did the 5 speed swap my car likes to idle at 2k. Every third time or so i drive it it will idle normal. if i shut it off and restart it right away the idle stays high. any one else had this problem any ideas? where to start, other abnormal problems etc.

Dessertrunner · #2 11-08-2007, 04:02 AM

I have spent half my life with high idle but seem to be ontop of it pretty well now. In my case it was a number of problems over time not just one. Since your problem started after the gearbox change check the following.
Use a mirror and check under the snorkel to see if the rubber is folded back and leting air in. This is the first place to look.
Check that all the hoses underneath are pluged in and none of the smaller ones like vacum got left off.

See how that goes first.
Tony

jeffast · #3 11-08-2007, 03:43 PM

ok so no vaccume leaks. I noticed today that if i drive it till it warms up park it for 5 minutes then get back in and drive it it idles normally around 800-1k. could my cold idle valve be sticking open?

TomsSVX · #4 11-08-2007, 03:48 PM

No, this is the result of the 5mt swap. We have been dealing with it for years. Until I can hack a stock ECu with a 5mt in it I really cannot do much to fix it

Tom

SVeXy96 · #5 11-08-2007, 04:54 PM

Quote:

Originally Posted by TomsSVX

No, this is the result of the 5mt swap. We have been dealing with it for years. Until I can hack a stock ECu with a 5mt in it I really cannot do much to fix it

Tom

What is stopping you from hacking it? No time? No clue? I don't know anything about ECUs so...?

TomsSVX · #6 11-08-2007, 05:22 PM

not time, don't have my ROM reader/writer yet. Plus, I don't have a stock car to work on

Tom

Trevor · #7 11-13-2007, 10:55 PM

Quote:

Originally Posted by jeffast

ok so ever since i did the 5 speed swap my car likes to idle at 2k. Every third time or so i drive it it will idle normal. if i shut it off and restart it right away the idle stays high. any one else had this problem any ideas? where to start, other abnormal problems etc.

In view of the fact that the problem is intermittent, obviously a change must be taking place. It would appear that all possible air leaks in tubing etc. have been investigated. I also assume that the throttle is not sticking in any way, and closes properly at all times.

The remaining likely inlet of air is confined to the Bypass Air Control Solenoid Valve and the Auxiliary Air Control Valve.

The BPACSV comprises a rotary solenoid, held in the normal idling position by means of a permanent magnet, which provides only limited torque. The associated rotary valve could very easily become prone to sticking in an open position, i.e. in the controlled position, normally used to counter temporary parasitic loads. Although access is not easy, dismantling, cleaning and checking the mechanism is a simple procedure.

P.S. The air inlet to the BPACSV consists of a quite large flexible tube, which runs across under the throttle body, to a junction under the main air inlet duct. If you disconnect this tube at the duct, you should be able to get it into a position whereby you can inject some solvent down it, so that this reaches the rotary valve. CRC petrol or whatever may dissolve gunk. If you switch on the ignition, then the air conditioning on and off a few times, this should operate the valve.

The AACV is more robust, mechanical temperature reactive and I would rate as the second most likely culprit.

jeffast · #8 11-13-2007, 11:11 PM

ok, i drove it all day today, and the idle seems to have settled down, i'll post what happens after i have driven it for a few days.

Trevor · #9 11-14-2007, 12:25 AM

Quote:

Originally Posted by jeffast

ok, i drove it all day today, and the idle seems to have settled down, i'll post what happens after i have driven it for a few days.

Note the P.S. I have added regarding a possible method of cleaning the valve.

jeffast · #10 11-14-2007, 02:05 AM

got it if i have trouble tommorow cleaning the i.a.c. will be my first step

Guyver280z · #11 11-14-2007, 07:38 AM

Well... my car is been idling from 2200 to 1800 consantly.... since I cleaned the IAC, maybe i did something wrong, i cleaned it with carburator cleaner... then took the electromagnet out and lubed the inside with WD40... I wonder if the WD40 could affect the electromagnet..... Also..... before cleaning it my idle went from 1600 to 500 in a very slow motion... wich makes me believe the valve was partially clogged but working, and now its not working or is on open position all the time.

I noticed it has an adjustment similar to the TPS sensor.... but I left it in the exactly same position it was before taking it appart.... is there a way to test it?? If I turn on the AC the valve should move and change the idle???

Thanks.