Had a very weird thing happen this morning on the way to work. Started the car in the garage and backed out like normal. Was just putting down the driveway (about 400 feet) and the idle started getting real rough and lopey. I thought the car was going to die. So I stopped and put her in nuetral and tried to rev it up to clear it out and nothing happened. I pushed and pushed on the gas pedal and the idle never changed. So I decided to shut it off and restart. All was well after that. No codes, no rough idle and everything seemed normal. WTF? Thottle body cleaning time?
Scott

 

Are you saying the RPMs didn't rise when you opened the throttle? If so, it sounds like the throttle body motor is kaput. I think this was an issue with your MY.

 

Yes... the rpm's didn't rise at all when pushing the gas pedal for about 10-15 seconds when it was rough idling. Nothing happened. Issue with my MY? Explain please.

 

IIRC some 05-06 stangs had defective TB motors.

 

I would just clean it and see if it happens again.

No need to get worried yet.

 

After almost three years of ownership, I'm becoming more and more convinced that the computers in these cars have gremlins. A year or so ago, I had a rough idle issue intermittently, mostly after the car sat for a number of hours (overnight, or when leaving work). The car would start just fine but then immediately the idle would drop, become very very rough, etc. I would have to floor the gas pedal, and it would blow a sizeable amount of smoke out of the back, then would come to normal after a few seconds. I tried different tunes, reflashing to stock, etc. Then all of a sudden, it went away and hasn't happened in probably a year now.

Just yesterday on the way home I received three trunk open messages- but the trunk was closed and hasn't been open since last weekend. Weird stuff once in a while....

 

Scott, your not alone. I've had that issue sporatically with my car. Only happens every so often. Usually when it sits for an extended period of time, or after driving somewhere and it sits for hours before starting again (mostly when its HOT out, and I mean humid hot). Same exact symptoms as what Tom described. Start it up, rough idle, when I floor it, exhaust pops, and then its fine. I plan on cleaning both the MAF sensor and the TB this Sunday, so maybe thats the problem. If not, maybe the TB is bad? Don't know. Hasn't happened for a while now (well over a few months). I always thought it was a bad plug or bad coil.

 

Your throttle pedal does not control the throttle body. The throttle pedal does control the throttle body MOTOR which is electric. Replace the throttle body motor.

 

There was actually a thread about this a few months back. The same symptoms were happening to another S-197 owner. He took the throttle body off, cleaned it with a universal cleaner, resinstalled it, and noticed the car performed significantly better. Sea Foam actually makes a great throttle body cleaner that you can pick up just about anywhere. Good luck!

 

I wouldn't just put a new motor on. Clean the MAF and TB and go from there.

 

Yeah I agree. Seems extreme to me considering it is my first issue and have not done what may be considered just a normal cleaning procedure for these cars. Anyway I bought some throttle body cleaner tonight and cleaned the TB. I should have taken some pictures but I didn't. There was an oily black deposit behind the blades. I worked the motor by hand and it did not seem sticky. I have to admit it is hard for me to believe that little bit of gunk is the problem but I will eliminate it first. I also had no issues on the way home tonight and I check for codes again and had none. For the record I have 24 K on my car and the TB has never been cleaned. Time will tell but it is really wierd to step on the go pedal for 10 -15 seconds and have nothing happen.

 

Hey Jeff,
Got 2 cans of Vavoline TB cleaner for $5 bucks tonight at Autozone.( some kind of special) Took about 30 minutes to do the cleaning and that was dealing with the CDC shaker. Not sure if it will cure my problem but it was easy to do. I suggest you give it a shot.
Scott

 

Scott,
Also check & see if either of the screws holding your MAF have loosened up.
I had a similar problem a few months ago, just a rough idle when cold though, no response issue.Turned out the screws holding the MAF had loosened up.

 

Thanks Larry. I will check them tomorrow night!

 

Are there any write ups on how to clean the throttle body?

 

We can do one now. remove the CAI elbow, loosen 4 bolts, remove TB, clean w/ TB cleaner and a clean cloth, front and backs of the blades. Reinstall making sure the gaskets are seated properly. I'll let others add if I'm missing something since I haven't done this in a while and am not near my car.

 

The oily black gunk is normal. It's been that way on throttle bodies for years. Cleaning the MAF sensor wire and TB is a good idea, but don't forget about the motor for the time being. Remember that your throttle is no longer mechanical.

 

I did a blurb on my site: http://www.modernponycars.com/nitrouspurgeinstall.htm

maybe this'll help.

 

Excess oil film from performance air filters on the mass air meter filament will cause similar problems too. Use a Q-tip soaked in electronic contact cleaner and clean the mass air meter might help too. I had a '99 LS1 F-body that had issues and a quick clean if the mass air internals cured it. Don't use excessive amounts of oil on the filter. Ironically my filter was pre-oiled from K&N and it had too much oil. That was about 6-7 years ago so hopefully the QC department in the K@N oiling dept. is doing a better job now. I have had a similar pre-oiled Mean Green brand filter on my Silverado for 4 years and 35K miles now with no mass air oil problems.

 

Over oiling can be a problem. I THINK I have this licked currently. I have two filters, so I can swap out the clean/oiled one for the dirty one and get back on the road quickly and then clean the dirty one when I have the time and/or desire.

After cleaning and drying it, I oil it a bit heavier than normal. Then, I wrap it loosly with about three layers of paper towels and stuff it inside a Food Saver vacuum bag. Then it gets vacuumed down enough to pull the paper towels snugly against the filter (without crushing it! This IS a vacuum, so...) and then heat seal it and leave alone until it is needed.

The paper towels wick out the extra oil while it sits on the shelf and because it is totally sealed in the vacuum bag, I can leave the oiled filter sitting out on the shelf in the garage with the other parts and I don't have to worry about it getting dirty. And because the paper towels will wick off any excess oil, when I do take it out of the bag, it is perfectly oiled and ready to go.

As for cleaning the MAF, I just used a can of MAF cleaner to spray off all the crud on the resistor elements. Give it a good spray to blast off the loose stuff then let it sit for 5 minutes or so. Then hit it again and the rest of the gunk should come off leaving a nice, clean MAF element ready to be reinserted in the CAI.