I.A.C. to blame? - Toyota Nation Forum : Toyota Car and Truck Forums

kev12mich · 08-16-2008, 05:49 PM

I've been having a problem with lots of misfiring at idle speeds with my 1992 5SFE Camry.

Heres the issue. Whenever the car is idling, or having an RPM below about 1,200, it misfires continually. However, whenever I step on accelerator, there is no more misfiring. I've recently given it a tuneup by replacing the spark plugs, wires, distributor cap, and rotor. Didn't change it a bit.

It seems to me that the only thing that could to blame would be the IAC. Although I'm not getting a check engine light at all. So maybe it's just dirty? I've tried cleaning the throttle body and spraying some deep creep down there, but it doesn't help. Would taking it off completely and giving it a thorough cleaning help? If so, how do I remove the IAC?

jaybur_racing · 08-16-2008, 07:23 PM

I have the same exact issue, misfires at idle only. I have taken my IAC off, and cleaned it out, as well as the EGR. and no change. so this would be helpful to know the answer to.

kev12mich · 08-16-2008, 08:04 PM

Quote:

Originally Posted by jaybur_racing

I have the same exact issue, misfires at idle only. I have taken my IAC off, and cleaned it out, as well as the EGR. and no change. so this would be helpful to know the answer to.

Did you measure any resistance values of the IAC to see if it's fully functional? I really can't think of any other reason that there would be misfiring ONLY during idle.

I think I might do another throttle body cleaning, along with some seafoaming to see if it does a thing. I really don't want to have to replace a $100+ part when I just gave it a tune up and replaced the ignition coil.

jaybur_racing · 08-16-2008, 11:21 PM

I did not measure the values, although I could have. I was reading some reviews on carsurvey.org that said they replaced their IAC only to have the same issues come around shortly after.

for me its not worth $100 to solve an idle misfire issue, or possibly only attempt to solve it, which is even worse.

1996camry · 08-17-2008, 12:35 AM

i don't think your IAC sensor is the problem.. DOes your RPM go up and down at parking or at stop light? if that was the case, you need to clean your body throttle for better gas milage. Misfiring, it sound like your MAP sensor go bad... if your MAP sensor go bad, you get a misfire.. check your MAP sensor..go junkyard, get a used one...that is another way to go...or get aftermarket MAP sensor..it works, too.