very high idle

[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.

[Dessertrunner]

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]

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]

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]

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]

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

Tom

[Trevor]

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

Tom

Tom,

Have a gander at my last post here:-

http://www.subaru-svx.net/forum/showthread.php?p=507453#post507453

Cheers, Trevor.

[Crazy_pilot]

... I don't have a stock car to work on

Tom

Gee, I'd love to have your problem:D

[jeffast]

Gee, I'd love to have your problem:D

+1
arg damn minimum charter count to post

[TomsSVX]

well why don't you try what trevor was suggesting in that link.... Looks to be a good fix

Tom

[Dessertrunner]

I just remembered a simple test to find out if the idle problem is 5 speed related or a physical. Turn you off your enviro system if the car idles with it off then its the 5 speed issue if its doesn't then you have a air leak problem.
Tony

[Trevor]

I just remembered a simple test to find out if the idle problem is 5 speed related or a physical. Turn you off your enviro system if the car idles with it off then its the 5 speed issue if its doesn't then you have a air leak problem.
Tony

Tony,

What you are indicating is that the five speed problem does not exist when the enviro/AC system is loading the engine. :confused:

Is this in fact the situation, as this represents an important clue?

[Dessertrunner]

Yes it is very evident, also I think the stall problem is less if you run with the Eviro system off, this is what made me think the valve we are talking about in the other thread is over doing everything looking for a transmission load. I also supect but haven't confirmed that Tom's problem is the ECU is trying to pull the engine back fast so its cutting fuel. Because his engine is more responsive he is feeling the problem more. With the fuel thing I can't see any other choice but to rewrite part of the ECU code which will be real fun. Phil said it appears that the ECU works out a value but then over writes it in a couple of place in the program my guess is this will be Knock Sensor being to high and also the ECU wanting to slow engine fast based of the rate of speed drop and throttle gradient down curve.

[huck369]

Jeff,
I haven't had a high idle problem on any of the 3 5-speed SVX's i'd had/done....except the first one, and it was i had left one of the tubes on the underside of the snorkle loose...installed it, and everything was fine.

I'd keep looking for a vacuum leak...in the Eviromental system...the brake booster, the PCV system...

That's all I got...:confused:

[jeffast]

Jeff,
I haven't had a high idle problem on any of the 3 5-speed SVX's i'd had/done....except the first one, and it was i had left one of the tubes on the underside of the snorkle loose...installed it, and everything was fine.

I'd keep looking for a vacuum leak...in the Eviromental system...the brake booster, the PCV system...

That's all I got...:confused:

hey huck what wires do i need to run to the clutch pedal, i think that might be part of my problem.

[huck369]

hey huck what wires do i need to run to the clutch pedal, i think that might be part of my problem.


I don't remember off hand.....but they are described in my write up (in my sig)

[jeffast]

I don't remember off hand.....but they are described in my write up (in my sig)

i don't know how i walked past that three times

[huck369]

i don't know how i walked past that three times

Ahh...you were justto excited about making it a 5-speed to read it that close:lol::lol:

[jeffast]

well i can start my car from the inside now, but it still idles at 2k

[huck369]

well i can start my car from the inside now, but it still idles at 2k


Well....that's an improvement;)

Check for a crack in the plastic intake tubing.....

[Trevor]

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]

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]

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]

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

[Guyver280z]

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.

[sd2649]

I had this ame problem with mine, it was clogged and I cleaned it up. Apparently it had been clogged for a while, because it had been adjusted to compensate for the gunk coated throttle body. I think the main difference was actually cleaning the throttle body butterfly valves, they were completely closed because of the gunk before, but now they have a small gap all the way around them. To compensate, I adjusted the IAC farther closed. I left the valve approximately 1/3 the way open when unplugged and in place in the throttlebody. Try it, I bet it works for you!

BTW, if it's a little off at first, it will adjust over a few days and be back to normal in no time!

[Guyver280z]

I had this ame problem with mine, it was clogged and I cleaned it up. Apparently it had been clogged for a while, because it had been adjusted to compensate for the gunk coated throttle body. I think the main difference was actually cleaning the throttle body butterfly valves, they were completely closed because of the gunk before, but now they have a small gap all the way around them. To compensate, I adjusted the IAC farther closed. I left the valve approximately 1/3 the way open when unplugged and in place in the throttlebody. Try it, I bet it works for you!

BTW, if it's a little off at first, it will adjust over a few days and be back to normal in no time!

So I have to take off the TB again in order to adjust the IAC right???... well, here we go again :lol:

[Trevor]

So I have to take off the TB again in order to adjust the IAC right???... well, here we go again :lol:

Later in the day, I will do a write up on cleaning, testing and adjusting the BPACSV (IAC) valve.

[Guyver280z]

Later in the day, I will do a write up on cleaning, testing and adjusting the BPACSV (IAC) valve.

You rock!!!
http://www.youthink.com/quiz_images/quiz1579outcome4.jpg

[Ricochet]

Make sure your intake hoses are fastened to the throttle bodies all the way. Last time I took mine off, I put it back on with part of one of the two rubber circle tube thingies bent inward, letting in air. It would idle high sometimes, other times idle normally..

[Trevor]

By-Pass Air Control Solenoid Valve
Cleaning, setting and Testing.

Description.

The By-Pass Air Control Solenoid Valve, or Idle Air Control Valve, allows the Engine Control Unit/Computer, to adjust the inlet of air after the throttles, in order to control idle speed. One obvious function is to increase the airflow when the air conditioning system imposes an extra load on the engine.

The unit comprises a rotary solenoid valve, biased towards a central rest position, by means of a permanent magnet. A double wound coil provides reversing open closed operation from a mean rest position, at which point the valve is half open. This arrangement provides two way variable control, dependent on the applied voltage.

Three electrical connections are involved. The centre pin on the connector is common to both windings and is energised positive. The remaining two connections provide for open and close operation of the valve.

Cleaning and Adjusting.

Cleaning is best achieved by removing the solenoid coil by undoing the two attachment screws, which pass through slotted holes so as to provide a degree of adjustment. Make a scratch mark so that the original position can be retained after reassembly. Magnetic force will be apparent as the solenoid coil is separated from main body.

The armature which rotates in ball races, when moved by hand should rotate open closed, with virtually no resistance. The valve should be cleaned of foreign matter using a suitable solvent/lubricant so that it is completely free to move.

After reassembly the valve should rest in a position, half open and half shut when set to the original mark. If there is a large discrepancy, this may indicate that the setting has been tampered with at some time and it should be reset.

Testing.

The solenoid resistance should measure 9 ohms, each side of the common connection, i.e. 18 ohms overall, a small tolerance being acceptable.

With positive to the common connection, 8 volts DC applied separately in turn to the two remaining connections, should fully open and close the valve from rest. Return to the rest position should occur, reliably without hesitation. In the event that 12 volts must be used, this will suffice for intermittent testing, but the extra torque available must be appreciated,

If a variable voltage source is available, continuous opening closing according to the applied voltage can be reproduced. However this test is in no way a necessity.

[jeffast]

fixed, no more high idle, idles at 2k till it warms up then drops down to 900, no problems what so ever

[Trevor]

fixed, no more high idle, idles at 2k till it warms up then drops down to 900, no problems what so ever

All is not as it should be. Normal warm idle should be 610 +- 100 RPM as per specs and idle speed should not exceed 1,500 RPM at any time. A car with manual transmission should be no different. I would rate a a quick drop in revs at shut throttle, as being very important, and this calls for a low idle speed.

My car normally idles at no more than 600 RPM. During a very short warm up at 1,100 RPM or less, and then never at more than 650 RPM, regardless of parasitic loads.

P.S. My last detailed post was intended for Guyver280z. I trust that he does not miss it.;)

[Guyver280z]

Great!!! Thanks Trevor... that was clear and seems to be easy to do, so i'll try that this weekend.

I noticed while my car was idling at 2,000 when I turned on the A/C the idle went down to 1500/1300 and slowly settle down to 1100/1000.... i think im going to need to replace my valve anyways... but first ill try to test it like you said :cool:

THanks.