Hi All...

On our Auto TL Wagon, when the car is Idleing, there seems to be a small Vibration coming from the Motor.. a bit like a stutter, or misfire... I usually will just wack it in Netural which seems to make the Vibration go away!!

I noticed it a few weeks ago, and forgot all about it, as my wife usually drives it, and she hasn't complained about it...

It has 112,000km on it, and had the Major Service done on it at 105k..

Any Idea what I ca look at??

Thanks Guys..!!

likely because the idle is dropping too low, try cleaning the throttle body and maybe even looking into the isc (idle speed controller) I dont know much about inspecting the isc but someone will be able to tell you the best way.

were the injectors cleaned at the major service or does the aircon being on make a difference? It could be just running rough. Are all your engine mounts in good shape? This issue has come up in lots of other threads and the cause can be many different things.

My mother's TL has the same deal, from when we bought it at 30,000 to now at 70,000.

I have noticed it idles really low, around 500rpm when warm, but since she only drives it 5km a day these days, I've not bothered to look into it, since like your wife, my mum doesn't complain about it. :ninja:

Probably the spark plugs, my TJ is doing the same and at 127,000km and I think its still on the original plugs (need the money for the plugs before I replace them).

Idling at 500RPM is way too low...Needs to be bumped up a bit....that should solve the roughness.

my girlfriend has the same issue in a tf. how do you turn the idle up?

my girlfriend has the same issue in a tf. how do you turn the idle up?

Idle screw on the throttle body or could be a faulty idle speed control unit.

my car had a similar issue over the weekend, after working on my cars electrics. idle OK when not under load, but slowing when either the air con switched on, or the auto was in gear did not think it was ISC, as it was ok not under load. I reset the ecu and resetting as per theapproved technique and it is now working fine. Also thought that this is a syntom of the battery going low.
cheers,
HK

Not really a solution for this thread but I have similar issue with my tj wagon seems to run rough at idle, and ECU keeps droping revs to 500rpm. ive changed plugs, leads, idle motor, tps, replaced gaskets on inlet manifold, disconnected battery overnight, even got the torque converter rebuilt, upped the idle but the ECU keeps re adjusting it within 15 minutes of driving back down to 500 rpm. put the ac on and up it goes to 900rpm then settles back to 500, put it in gear and up the revs go to 900 then settles back to 500rpm. you can hold foot on pedal to keep 900 rpm and stops the car shaking but engine still feels rough. also taken it to two mechanics and they cant figure it out frustrating. any help or experience would be usefull.

hmm hers is fine in park but when you put in drive with foot on break it shakes, how do i reset the ecu? leave the battery un plugged for a day? thanks

hmm hers is fine in park but when you put in drive with foot on break it shakes, how do i reset the ecu? leave the battery un plugged for a day? thanks


Remove negative battery lead. Pump brakes for a minute to discharge any power left in the electrical system, then leave for a couple of minutes. Re-connect negative battery lead. If you have an auto, you will need to go through the transmission learning procedure as well...

ok would i get the same effect disconecting it and leaveing it over night? would that be a better option to make sure everythings reset? or does it realy work that quick. and yeah its an auto. how do you no if its going through the learning process again? thanks

You will have to go through the transmission re-learning process due to the trans ECU being reset.

You will get the same effect disconecting the negative battery lead and leaving it over night. It doesnt take long for everything to reset when the battery is disconected.

Not really a solution for this thread but I have similar issue with my tj wagon seems to run rough at idle, and ECU keeps droping revs to 500rpm. ive changed plugs, leads, idle motor, tps, replaced gaskets on inlet manifold, disconnected battery overnight, even got the torque converter rebuilt, upped the idle but the ECU keeps re adjusting it within 15 minutes of driving back down to 500 rpm. put the ac on and up it goes to 900rpm then settles back to 500, put it in gear and up the revs go to 900 then settles back to 500rpm. you can hold foot on pedal to keep 900 rpm and stops the car shaking but engine still feels rough. also taken it to two mechanics and they cant figure it out frustrating. any help or experience would be usefull.

I have the slight rough idle, and there is no actual misfiring going on, plus i know that everything is in perfect working order. It is due to the fact that it is a V6, and the firing order of these engines that causes the slight rough idle, in my opinion

My KJ is doing the same! I'ts got 124,000 on the clock. It apparently is a common problem for Magnas/Veradas in their twilight years! My Brother-In-Law, a 30 year mechanic, tells me it is a DIRTY THROTTLE BODY. He says the TB has to be cleaned using a spray can of CARBURETOR CLEANER. There is section in the workshop manual under 13A Multipoint Fuel Injection, On-Vehicle Service, Throttle Body (Throttle Valve Area) Cleaning. That shows how to do it. The method my BIL uses is slightly different in that he has the engine running when he does it. He has promissed to come over and do it for me. I have taken him up on his promiss and if anyone cares to wait until he can get around to do it, I'll watch carefully and take some pics of the process and post them (with comentary) in this forum!
Bill.T

i believe the ISC motor has to be removed from the throttle body before you squirt it with carby cleaner , or else the O ring for the ISC will be ruined.

The engine will stall if you remove the air intake tube from TB whilst running due to air flow meter not getting a reading that matches the TPS position.