I was having problems with high idle/rough idle and revving uncontrollably between shifts in my 5 speed mustang gt (1995). I believe I corrected that problem. I've repalced the TPS and the IAC. I also put a restrictor plate on the IAC which seemed to fix the problem with the revving between shifts. Then...for no real reason other than routine cleaning, I cleaned the Air charge sensor and the MAF (I have cleaned the MAF before but I had just cleaned my K&N filter so I figured I would clean it again. I didn't damage the wires, I looked). When I got in the car this morning after cleaning those last night...It runs like crap. Hard to get it to idle smooth when cold, runs rough and misses when I accelerate. It just runs rough, jerks around like crazy. It's like it doesn't want to go, spits and sputters when I give it gas and I hear the lifters clattering. Idle smooths out after a while but never began running smooth on the 45 minute drive to work this morning. Any ideas? It didn't start running rough like this till after I cleaned the MAF again and the IAT (I think that is the abbrev for the air charge sensor near the MAF). I had replaced the lower intake manifold a couple of weeks ago but I have checked and found no vacuum leaks whatsoever. This started after cleaning the MAF and IAT. Please help.
Thanks,

 

Cleaning the MAF can destroy it if you use chlorinated chemicals. Also, you mentioned cleaning your K&N. If that cleaning involved re-oiling, excess oil will coat the MAF wire and produce your problem.

 

^ exactly, k&n had a problem with this when they first came out and wrecked numerous maf sensors. Also, you do NOT need to clean an maf at all unless its giving you problems, then it only works as a temporary fix. The maf sensor is very sensative, I agree with matt and would say doing that work ended up messing with the maf.

 

Even after unplugging the MAF, it still does the same thing. I'm not sure if this is just a coincidence and maybe something else is wrong now or what. The IAT was dirty, so I cleaned it. i unplugged both of them, one at a time to see if I could narrow it down. The car acted the same even with them unplugged. Not sure now.

 

I had the exact same problem with my 95 Gt. I cleaned my air filter, and then it ran like crap. Once I cleaned the MAF later, it helped the problem, but it eventually came back again. I finally replaced the MAF, and I haven't had a problem since. Its been a little over a year, I do believe.

 

After spending all the money chasing parts and replacing them...I finally took my car to the shop. The distributor is bad and is being replaced. #4 wasn't firing at all. I thought this might be the problem as I had began to pull the plug wires one by one and #4 didn't seem to make a difference either way. However, when I tried to run the KOEO/KOER test...I found out that my check engine light isn't working. Just my luck! I couldn't run the test. I replaced the bulb but still...nothing. Exhausted with all the work I've put in to this car in the past month...I broke down and let a professional handle it. Now that the check engine light is being fixed - a wire had been broken at some point in the wiring - I will be able to run this test in the future. (but I hope I don't need to do that - fingers crossed).

 

huh?? I'd like to know what in the dizzy is bad and how they condemed it based solely on #4 not firing, now if it were missing randomly due to a bad stator or bad distributor shaft bushing, I can see that randomly causing misfires on random cylinders but to be focused soley on #4, would lead to a bad cap, wire, plug, or internal engine issue on that cyl and or a damaged spot on the reluctor wheel in the dizzy that coincides with #4 since all the stator does is ID #1 then fires ignition/injs in the firing order sequence...........so I'd be curious to see what was bad on the dizzy??

 

I'm not completely sure what all is bad. I spoke to the mechanic briefly and had to cut him off as I am at work and have spent way too much time on that car in the past couple of weeks and couldn't get away from what I needed to be doing here at work for longer than just a few minutes. I know # 4 isn't firing and the distributor is bad. I'm not sure what all is bad on the distributor. I asked if they were sure the distributor is bad and he said "yes, we're sure it is bad". I've never had any problems with this mechanic and he's been reliable with my mother's car troubles in the past so I took him for his word. If it had been a mechanic I'd never been to before or one where we'd had to bring something back more than once for the same problem...I'd have told him to wait and looked into it further when I had more time later or after work, if they were still open. But then, if I had to take something back twice for the same problem...I probably wouldn't be using him again anyway, especially for my Mustang. LOL. I will let you know though because I am interested to know myself. I replaced my lower intake manifold about a month ago and had to pull the distributor when I did that. It began to give me problems after that. I may have damaged it myself. At one point I caught my 11 year old son playing with it while I was working on the car. so...??. Prior to replacing the lower intake, which was cracked at the point where the thermostat bolts up to it (the previous owner did this).