My 88 cougar has been running worse and worse lately. I cant deal with this any more, and I cant sell it the way it is running. For over a year I have been dealing with the bad idol. At times it wants to pull my car well into 3rd gear without me ever touching the pedal. Some times it jumps up and down and eventually gets so low it just dies. I have baught a new TPS and cleaned the hell out of the IAC. Could my problems be elsewhere, or should I completely replace the IAC also?
I appreciate the input
Andy
uhhhh, has it had a tune up? it could be a number of things, pcv valve, timing, clutch, plugs, plug wires blah mine has some bad symptoms of rough idle i replaced all of the above - the clutch and it runs fine aside from the timing
Clutch?
REPLACE the IAC (99.999% likelyhood this is the issue)
Do these if you haven't in the last year:
-new cap/rotor/and plugs
-new fuel filter
-new air filter
it had new rotor cap plugs and wires less then a year ago along with the fuel and air filter. The timimg should be unaltered, I have no idea what a pvc valve is or does, and what clutch???
PCV - Positive Crankcase Ventilation
It is a $3 part and is in the middle of the passenger side valve cover. At least that's where it is on mine.
Quick check to see if the Iac is the problem.... Unplug it, the car should go down to a really low idle (400 - 500 RPM) and should stay there. If your base idle is off the car will stall. Have you pulled the koeo or koer codes? These usualy will let you know what is going on.
Oh yeah almost forgot, all autozones will check your codes for free. Some guys don't know how to do the koer test properly though. It will return bogus codes if they dont do it right. If they ask you if your light is on tell them it doesn't matter, most codes on an older ford don't trip the light anyway. Hell I unpluged the iac on my 88 cougar and the check engine light didn't even come on. Your car is OBD0 just in case you wanted to know. 91 was the first year for OBD1 and then 95-96 the changeover to OBD2.
not on EFI 5.0s, it's on the back of the lower intake. mine buzzes like crazy sometimes when I park, even after replacing it.
you can always do like I'm going to do, just swap it out for a HO :D
do as CougarSE stated
actually...warm the car up to operating temperature, then unplug the IAC, and it will idle down, check to see what your base idle should be set at via the sticker on your car or a manual, and turn the adjustment screw untill you base RPM is set proplerly
then, probe the signal wire from your TPS (cant remember color at the moment) with a volt meter, and try to adjust the TPS down to just under 1v, im not sure if yours is adustable, but it may be working elongating the mounting holes to get it to adjust, i did it on my CFI car, once its adjusted to just below one volt (mine is at .94), plug the IAC back in and see what happens
if all else fails, may be time to just get a new IAC
Thank You,
Unpluging the IAC made a huge difference in the idol. I think I am just going to replace it. If I still have anymore problems I will let you know.
Thanks again
Andy
yup, can you tell weve been there and had those problems.... Mine was on my ranger though...
If unplugging your IAC made a huge diff, your IAC is OK....
Yes generally it is. But I have seen iacs that are open or closed not inbetween like they are supposed to be. the stepper motor in them can burn out.