[AtlanticBlue99]

1999 v6 mustang. this weekend the car started to run a little hot (the gauge says normal, but the fan is on more and the engine bay is much hotter). the idle jumps from about 600 rpms to 1000rpms back and forth spurradically when in drive. auto tranny. what could cause this problem?

also, 95k miles on the dot when this happened. i am changing fluids this week, oil change is today.

it threw one code, p0113 for high air intake sensor voltage, but only because i left the connection unplugged by accident when removing the intake tube. after plugging it back in, the code went away. the cel is not on, no other codes.

any ideas?

[Bossman351]

Deffinately sounds like a sensor/meter of some sort. You siad you chnged the 02 sensors with the header install right? Maybe check to see if one of the wires didnt lay on the header and get burnt. Could also be the IAC motor.

[AtlanticBlue99]

sensors are fine. the transmission is 2 qts low (i checked this afternoon) and tranny fluid is coating the undercarriage of the car. i think i may have some transmission issues now. it is an auto tranny with 95k miles on it.

[Turbostang]

Check the TPS sensor.

[AtlanticBlue99]

throttle positioning sensor is in good shape and plugged in. i did remove the cruise control cable, but that shouldnt have an effect. the cruise control cable bent and got binded which stuck the throttle open a couple times last week. friday i took the cable off, saturday the car ran fine, sunday afternoon the car ran like shit, not making hardly any power at all until 2500rpms. if the tranny is leaking and fluid was 2 qts low, there has to be something wrong their right?

the car was running hot, now it is running normal temp, jut no power at all hardly below 2500rpms...

[mdvaldosta]

Start with a good tuneup:

plugs
wires
cap
rotor
fuel filter (good possibility)
air filter

And look for loose vacuum hoses. For idle surge it's usually a TPS or IAC problem.

[AtlanticBlue99]

i checked all the hoses and vaccum lines. the spark plugs are about 15k miles old and the wires are the same. i could replace them if need be. Air filter is fine, fuel filter is a possibility. this may sound dumb but where is the fuel filter on my car? by the gas tank, up front? it just feels like even with the throttle all the way down, i make now power down low. like something is holding it back

[AtlanticBlue99]

also, you can clean the idle air control valve with carb cleaner right? just undo the electrical connection, undo the 2 bolts, spray it down with carb cleaner and put it back on. is that how you would clean it?

[mdvaldosta]

Yea carb cleaner is fine. Really though throttle body cleaner or brake cleaner would be better because they don't leave a residue. I doubt it's your IAC causing driveability problems, idle problems yea but not costing you power. Definately look into the fuel filter, it'll be back by the gas tank, follow the fuel line.

[AtlanticBlue99]

okay thanks. ill clean the iac today while it is still light out, then tomorrow after school i will replace the fuel filter and get back to you. i might have time for both tonight.

[mdvaldosta]

Get a fuel line disconnect tool, their cheap and you'll probably need it to get the fuel line off.

[AtlanticBlue99]

thanks. ill hit up the autoparts store tomorrow and get back to you to see if these solved my problems.

[87vert]

Originally Posted by mdvaldosta Get a fuel line disconnect tool, their cheap and you'll probably need it to get the fuel line off.

he shouldnt need a tool to get off the fuel lines, those are for taking the lines off at the rails, the filter should just be held in by two white plastic clips that just snap out and in.

[lemon]

hmm... the iac could cause some lost power at low rpm's, couldnt it, because the computer registers the iac position, but it could be getting stuck while retracting or something, and ~2500rpms gives it just that much vaccuum to pull it in to close up the iac, and restore the power?

i dont know, but i do know about the surging idle, but thats not exactly your case ab. so good luck

[AtlanticBlue99]

well the idle is steady again after using some carb cleaner. i had some carbon actually drain out of the throttle body when i sprayed carb cleaner in it. it was a little hesitant to start the first time using carb cleaner, but the idle is normal again.

i will swap the fuel filter out tomorrow afternoon. my low range power is still gone which really sucks when stopping then needing to get back into the flow of traffic. i do have a tranny leak, but hopefully that isnt affecting the problem here. if so, i could always get a 5 speed and learn to drive a stick better. i just dont want to spend money on a tranny rebuild or a new tranny/clutch assembly if i dont have to. ill keep yall posted

[87vert]

you have tried resetting the computer right? disconnecting the battery for ~15mins

[AtlanticBlue99]

disconnected negative battery terminal for half hour while letting car cool last night. then disconnected positive terminal for the rest of the night and rehooked it up this morning and reflashed it with the sct xcal 2 twice and no codes came up after 7 starts and 30 miles.

[Bossman351]

Put a socket on the tranny pan bolts and give em a good one handed twist. They may just need retightening to reseal the pan gasket and stop the leak.

[AtlanticBlue99]

i will do that tomorrow. the leak isnt noticable like a drop or anything. it leaked 1.5 qts over a period of 20k miles.

[87vert]

where is it leaking from? normally a trans leak can be fixed without a rebuild, usually from the pan or the dipstick.