[my98stanggt]

Hey all I am new on here. I just got a 98 GT and I am having the problem of it hesitating at a stand still idle. I pulled the plugs on it today and I noticed that all 4 on the drivers side had a black residue all over them while the ones on the passenger side looked like they were normal. could this have to do with the IAC or MAF? was also wondering if it could possibly be the coil packs? How would I know what it is? I did try and clean out the MAF and the IAC and will know how that worked out tomorrow. the IAC was dirty inside with the a lit coating of the black stuff also, but the plugs were covered in it.

[threeravyn]

Thought I'd post my woes on here and hope for help.
I have an 01 GT convertible with about 52000 miles on it.
Last week when I was in gear with my foot on the brake I kept hearing a sound like a helicopter in the distance.
Today it not only made that sound but was idling up and down to the point where it was stumbling at lights. Neutral evened it out a little.
On the interstate it would lug off and on at a steady speed.
I've had my MAF go out before, but this feels different.
I'm wondering if humid air affects cold air intakes that much. It's a K&N cold air kit.
Thanks for any help in advance!

[my98stanggt]

Well I cleaned both the IAC and the MAF. Dont know if it helped or not. It ended up being my O2 sensor on Bank 2 in the front. Now I dont have anymore hesitation.

[Struck]

How about some more issues? My wifes 04 automatic GT. Bone stock outside of exhaust, but this occured even before that. Anyway, it has an intermittant hard start and hesitation. It will die after first starting it almost everytime you get gas, sometimes after it sits for 30 min or more, and it will hesitate pretty badly for a few seconds after acceleration from a stop sign with a moderate amount of throttle. New parts from ford include-

Plugs
Air filter
Fuel filter
Fuel pump (Bosch))
IAC
Battery

Any ideas? It has no faults according to my xcal2 for my lightning. Only thing I can think is maf, fuel pressure regulator, or possibly injectors? And I also did run seafoam through the fuel tank, although it did pickup some mpg's, but didnt cure my drivability problems. Thanks in advance!

[combatmedic]

yeah but what if it says the no 7 cylander is not firing, but there is spark , but 2lbs of pressure??? am I stuck

[cobramustang98]

i have been having the same problems bad idle and such and every time it acts up i just use some maf sensor cleaner and it clears up right away and i dont have no problems for about 4 to 6 months

[cobramustang98]

Originally Posted by threeravyn

Thought I'd post my woes on here and hope for help.
I have an 01 GT convertible with about 52000 miles on it.
Last week when I was in gear with my foot on the brake I kept hearing a sound like a helicopter in the distance.
Today it not only made that sound but was idling up and down to the point where it was stumbling at lights. Neutral evened it out a little.
On the interstate it would lug off and on at a steady speed.
I've had my MAF go out before, but this feels different.
I'm wondering if humid air affects cold air intakes that much. It's a K&N cold air kit.
Thanks for any help in advance!

i encounterd the same problem you are describing and my problem was my crankshaft sensor was having problems i replaced it and the symptoms went away

[threeravyn]

2 of the boots were split and my plugs were a bit fouled up. Replaced plugs and everything and now she runs nice again.
I was hoping that would get rid of the putting/helicopter sound, but guess that's unrelated. Drives me nuts.

[TomGT]

I have a similar idle problem here (with my 96GT Auto 62K miles)...when stopped at a light (in drive) I'll get some surging/high idle. But when I put it in Park It'll just die.

It just seems like it SHOULD be the IAC...BUT, according to the great sage Chilton, if the resistance on the IAC's terminals measures between 7-13 ohms, it's good to go. Mine measures 11 ohms, so.......?

I

[TomGT]

Gently cleaning the two little MAF sensor elements with a Q-tip and some carb cleaner did the trick for now. Idle is a rock-solid 600 rpm in Park and Drive.

[OBGT]

I have an 01 auto gt and every time I start the car when its cold it seems to idle a little rough and the exhaust seems to pop a couple times, but after it warms up all these problems go away. I've also noticed recently the car has been very sluggish under WOT and when I put it in park sometimes it will drop revs and almost die or stay at 1000 rpms. The IAC and TPS were both replaced about 3 years ago, could they be going out again?

[slslinde]

My 96 mustang Gt runs smooth as a baby, at stop lights, but when I stop to put it in park it just cuts off! no stumbling , rough or any thying just cuts off. Is it my IAC and if so should it not throw a code?

[c0dblack]

I have a 98 mustang gt that has some similar problems. The weird thing is that I bought a brand new IAC from autozone and as soon as I installed it the car would ildle very low, almost to the point it wanted to stall. I took that one back, bought one from O'Reily and it did the same thing. I cleaned the old one with carb cleaner and it the car started working fine. Does anyone know why the car had those symptoms with both new IACs?

[geobooy]

In response to the last two posts.
Disconnect the Neg terminal of the battery for 20 minutes.
That will clear out the CPU learned fuel air ratios and force the
CPU to default to the base programming.
It basically has to relearn how to breath. Doesn't take long. Just a couple of minutes.

I had the same problem.
What I did was replace the IAC, and TPS.
Then I cleaned the MAF and sprayed carb cleaner through the PCV and EGR valves until they were clean.
I also took the throttle body off and clean the area around the
butterfly valve, you'll notice some dirt build up where the valve
sits when closed.

I had the neg term of the battery disconnected the whole time.

Now I am running fine along with my idle.

[c0dblack]

Thanks for the info. I will try that and let you know the outcome.