Random high idle

[sjbsuperman1425]

This has happened a couple of times recently. I'll be driving and everything is fine, and out of nowhere, it will idle at 1400rpm like its on cold start up. Somedays it does it somedays it doesn't. I'm ruling out vacuum leak since its totally random and putting my guess as faulty AAC valve is the culript (haven't pulled codes). Thoughts and comments?

Also, my Air regulator has been replaced, but seems to only work when its cold out. its been about 50-80* here recently and it just doesn't idle up on cold start up like it did when it was in the 40* weather. think it could be related to my current issue?

[boost_boy]

Watch the water temperature sensor and it's connection. It has the ability to cause a high idle with a hard-to-start condition as well. May not be the answer to your dilemma, but I'm just putting that out thereas an FYI.

[sjbsuperman1425]

I replaced the ect a couple years back. Should be ok... Ill check codes after work though. That info is good to know though. Thanks Dee

[sjbsuperman1425]

No codes. All connections good. Swapped aac valve assembly and helped a little bit. Only idles high when the engine is warm ans the fan turns on. I'm stumped on yhis one...

[sjbsuperman1425]

Well here is what I did. No Codes Present:

1. Changed AAC valve with a spare i had. no change in condition. runs the same.
2. crimped off all BIG hoses for IAC vavle, air regulator, recapped the TB nipple. No change UNTIL i crimped the hose coming off the Intercooler cold pipe to the manifold just behind the throttle body. I have not yet tried to crimp the brake booster line either.
3. Tried disconnecting AAC and FICD and no change after a drive and warm up.
4. TPS is still within spec.

Fuel pressure is
28-30psi with engine running. AFR when this occurs are about 14.8-15.2. If i boost the engine a little bit sometimes, it will act normal.
Reading the FSM, they want me:
1. check timing (has been spot on)
2. check air intake ducting
3. air regulator
4. TB for clogging
5. fuel pressure
7. AAC vavle
8. FICD
9. Self-Diagnosis Mode III

I check #1, 3, 5, 7, 8, and 9. But I have no boost leaks so i feel air intake ducting should be good, especially since crimping the cold pipe-manifold hose changes the RPM. I have NOT check the TB for anything so maybe that will shed some light..Anymore thoughts guys?

[sjbsuperman1425]

well, my friend took it for a ride and check it over, and apparently the timing was off and now it set back to where it is supposed to be...before it was maxed out turned counter clockwise, now it is right back in the middle..can anyone shed light on this? lol <friend on left, me on right!

[sjbsuperman1425]

Ok so here's what I found. On cold start, the ignition timing is severly retarded, won't idle above 500rpms and is basicaly undrivable. I have to advance timing to 15* to be able to drive cold via the CAS. Once warm, the ignition timing is severely advanced and I have to retard it to bring the ignition timing back to 15*. Any ideas on this...?

[sjbsuperman1425]

UPDATE:
ECU had a code 13 (ECT) last night. changed it and code is gone. Problem persists.

with the engine running at full operating temperature, i can disonnect the hose that runs from just behind the throttle body on the manifold that runs to the cold pipe, plug the manifold side of the hose leaving a hole in the cold pipe, and Idle is rather decent if not right where it needs to be. Car revs and doesn't act like there is a new created boost leak. i can feel air coming out of the cold pipe port that is now open. My thought is I must have a vacuum leak, since the computer basically isn't recognizing a boost leak at low rpms.

[louiswun]

High idle might cause by TPS idle switch, if that switch not working properly, ECU will not switch to idle ignition timing from main timing map, and and the idle will become hi, it has been happen on my own car, just try to adjust the TPS to lower voltage like 0.4V and see how the idle goes.

[sjbsuperman1425]

well...im at a crossroad..for the longest time, my car ran great with the CAS turned all the way advanced, but the timing was set to 15*. it ran great, boosted great, idle good. this problem just recently started, but I feel like i have to throw everything I've down out the window because yesterday i found that the engine cont 10A fuse in the fuse/relay box on the passenger side by the battery location, was blown. I replaced the fuse and my cold start seems to work now, but my idle was still the same.

What i'm thinking of doing is going home, disconnecting the battery, cleaning the grounds, and then starting over on my whole diagnosis. the AAC wasn't getting proper voltage without the fuse so i'm hoping if I basically reset everything and go from there, it might get me to a point where I can fix this. the posistion of the CAS changed after i did my head gasket a few years back, so i'm going to put my CAS to its original spot when i first to it off, and start at that point.

for setting timing, do I do it with the engine cold or warm? Im trying to get square one and its hard now to set the idle and timing when it runs terrible all the time now.

[float_6969]

You really need to check the FSM for setting the timing. You do also need to double check the TPS. He's right about it not switching to the idle map if you don't, and then you'll just be chasing your tail.

[sjbsuperman1425]

Did the timing via fsm. Ran like poo..did It again and it u leashed a beast and ran beautifully for about 15 minutes. Then back to running decent or how it has been. I loosen the cas bolts to chsnge timing, and it corrects without even turning the cas. So after a week of sleepless nights, it's either a bad cas or cam splibe or both

[sjbsuperman1425]

Both teeth and guide look good don't you think? Bad CAS without it throwing a code. Any other thoughts or opinions?

[float_6969]

No way dude, that cam looks toast to me! The teeth on the cam shouldn't be "pointy", they should be round.....and now that I look at it closer, I think the CAS teeth might be damaged as well. Can you clean all that dust/rust off and take some more pics?

[float_6969]

I just DL'd both pics and looked at them blown way up. They're both damaged. You need a new cam (or at least the spline, JWT sells a replacement spline) and a new CAS. Sorry dude, but at least you've found the problem.

[sjbsuperman1425]

I'm buying tomei poncams tomorrow and picking up the new CAS I ordered on tuesday aling with a new water pump, tensioner, idler, and timing belt. Ill have it done by next saturday night. I'm pretty excited as odd as that sounds. Upgrades and a better running car? Sounds like a win win to me..but the $750 price tag Iis like "UGH!". Its probably been like this since I swapped the engine and just never new.

Oh, the wiring specialties harness fits pertty good. Installed that last night. Pretty cool it was free haha!

[float_6969]

Nice! With a set of poncams and a working CAS, it's going to run doubly betterer now, LOL!

[sjbsuperman1425]

Yea that's why I'm so excited haha. Hopefully someone has them in stock though..

[sjbsuperman1425]

well Tomei Poncams are 4 weeks special order from Tomei...I'm going to get the new CAS tomorrow and see if that helps the problem and keeps my timing in check until i can get some cams in. Good thing i know people in the parts stores and the new remanufactured CAS has a lifetime warranty

[float_6969]

http://www.jimwolftechnology.com/custom ... PartID=500
Pretty cheap part. I know you're getting new cams, but you could fix your car completely (the new CAS won't completely cure it) and have a good exhaust cam to sell to someone when they have the same issue you do. Just an idea.

[sjbsuperman1425]

to install that, can i leave the cam in the engine? it basically looks like you break the tab off, drill a hole, thread a bolt in the old pin to get it out, then hammer the new pin in?

[float_6969]

I've never done it, but IDK why you'd need to take the cam out unless you really have to beat the new part in. Then maybe it would damage the cam journals. There was another member on here that JUST did this within the last couple of weeks and I'm pretty sure he didn't take his cam out.

[float_6969]

ca18de-hesitation-t538941.html
Nope, he pulled the cam.

[sjbsuperman1425]

yea i've read through that. i'll probably just hope this is kind of a band-aid for awhile but get some Tomei cams on order and sell the set I have. Then someone can have either a cam for their intake side, or one they can fix!

[sjbsuperman1425]

installed the new Cardone Remanufactured CAS (Cardone part # 31-S5405) yesterday and I now have timing set to 15*BTDC. car pulls harder and runs noticably better cruising around town. still need the new cams thought (obviously). just glad I'm not running crazy advanced timing around town anymore