IAC Stuck Open??? - Toyota Nation Forum : Toyota Car and Truck Forums

toysarefun · 12-14-2004, 08:44 PM

95 5sfe. I know its open because air rushes through it but I have bad idle, and NO FAST IDLE when the motor is cold! Is it the thermo sensor or is the IAC only supposed to be closed when its cold?

This dang thing..

Also, when disconnecting the IAC with the motor running, the check engine light never came on like it says over at yotarepair.

Anotherwards.., how the hell does the IAC valve work?

Cheers

csaxon · 12-15-2004, 10:52 AM

http://www.se-r.net/engine/about_iacv.html

toysarefun · 12-17-2004, 01:30 PM

If the thermo sensor is bad, will it completely derail the IACV from making that clicking noise its supposed to make which is probably a sign that the IACV is functioning at least. Or is the IACV probably burned out.., guess I'll have to buy a service manual for the thing at this point. Sure can't afford the dealer anymore.., they give commissions to the reps for selling service.., way to many greedy middlemen everywhere you turn these days. Forget honesty and trust.., unless your dealing with friends thats history now.

Pineapple · 12-17-2004, 01:34 PM

If it stuck open, you'll have high idle all the time.
What do you mean by "bad" idle? Boncing up and down?

88 LE · 12-17-2004, 01:53 PM

You can test the ECT (engine coolant temp) sensor. See link below for instructions.

http://www.autozone.com/servlet/UiBr...3d8013e283.jsp

fredk · 12-18-2004, 09:03 PM

is it sucking alot of air through it when warmed up?

toysarefun · 12-19-2004, 12:52 PM

Yes when its warmed up it does suck allot of air, you can tell by covering it up with your finger. I also replaced the ECT sensor this weekend, hoping the old one was out of tolerance, but still no fast idle. Maybe then the IAC valve itself is shot, I hear they are not cheap. The car actually idles ok, runs fine otherwise.

fredk · 12-19-2004, 01:39 PM

when its warmed up, you should be able to plug it off with your finger and the motor should just stay running with everything off, clean up around the throttle plate too

toysarefun · 12-20-2004, 02:05 PM

It stays running, I did clean the throttle plate, that does help. I think the whole throttle body needs to come off and be cleaned. I'm not replacing the IACV, not for the money they want for it..no way. This thing is going right back to somebodys used car lot in the spring. I think the 5sfe is a great motor, but the sludge seems to plug everything up.

fredk · 12-20-2004, 02:17 PM

is the motor sluged up?

toysarefun · 12-20-2004, 02:24 PM

Sure it is.., its a known problem. I'm using JB engine tuneup with thinner oil to help clean the crankcase and oil passages out some. Hopefully the seals will survive this treatment.

fredk · 12-20-2004, 02:44 PM

hhmmmm, all ya gotta do is instead of 5 qts of oil, put 4 and 1 qt of atf, is your thermostat warming the motor up past 180?

toysarefun · 12-21-2004, 10:27 AM

This thing don't take 5 quarts, but you know.., just for the hell of it I'm going to throw some ATF in to top it off. Maybe the reason the things sludge up is because it only takes 3.8 quarts of oil and run so hot. Thermostat still works great, I've got heat within 2 or 3 blocks. The only problem is the no fast idle (ever), and when your in gear at a stop sign, the idle is so low that the car vibrates (about 500rpm), shifting into neutral its smooth again (idles up to about 1100). Personally I think someone messed with the TPS since the IACV does not seem to be working, and idle in neutral is a bit high. I've seen allot of complaints about these cars having vibrations similar to this.., very difficult to troubleshoot it seems, and never seems to be just one thing causing it.