I'm wondering if anyone can give me some suggestions. My 96 magna is idling very rough, even after it has been serviced, but if i place into neutral it is fine.

sounds like you need to get your RPM lifted.
when it is in D, what are the rev's sitting at?
try putting it in D, chuck the air con on. does it stall or idel fine?
same again, but what are the rev's sitting at in N with and without the air con on.

i will check it out, but from memory, when the air con is on it is worse in D and regardless of whether the air con is on or off, the front of the car shakes, in N if the aircon is on it isnt too bad, i think its actually fine. Also wants i place it in neutral say if i'm at a red light, as soon as i place it into D it gives a bit of a jump, unless you really place your foot on the brake hard and then put it into drive.

yeah too me it sounds like the rev's need to be lifted.
in my sisters old lancer that was the problem, and it almost stalled and 'hopped' when it went to D.
It should be around 750rpm at D idol (dont quote me, but thats what all my cars have been at)
get back to me on it, then you can jsut take it to a mechanic and ask it to be raised upto the correct RPM for your model/make (check your manual or online)

In N no Aircon it runs between 6 & 700 rpm
With Aircon around 500rpm

In D it runs no aircon around 500rpm
with aircon around 400 almost 300 rpm

yeahh thats too low :(
mine idols around 750 in D and about 800 or so in Neutral.
Take it to your mechanic and get it raised abit or if you know someone mechainically minded they can (i dont know how to tho lol) :bouncin: hope that works for you :D

I hope it's the solution to the problem also.:)
Thanks

I hope it's the solution to the problem also.:)
Thanks


no problem :)

Turn the idle screw on your throttle body up to the desired rpm
I did this on my Rada and it's been great

Optimal idle RPM for a 6g72 is 700rpm (±100rpm).

700 is fine, 500 is not.

The Idle Speed Control motor on the throttle body is supposed to keep the revs fairly constant, when the load on the engine (Drive, Air, Lights) varies. Check that it is working.
When the aircon cuts in, you should see an initial drop, then an increase in revs on the tacho.
When it cuts out, the revs will first jump up, then drop back. This is the ISC at work. If this doesn't happen, it is not working.

Thumping into gear is usually a throttle position sensor that has gone out of adjustment over the years.

If adjusted properly, with foot on the brake, a N to D or R shift should hardly be felt, even at a high cold idle speed like 1,200 rpm, and revs should only drop minimally.

My car does the same thing at lights - vibrations is felt coming from the front but I didn't know it was related to the RPM. I will have a look at the tacho to see where it sits at the lights tonight after work.

My car does the same thing at lights - vibrations is felt coming from the front but I didn't know it was related to the RPM. I will have a look at the tacho to see where it sits at the lights tonight after work.

Also have the same problem.. Car got serviced on the weekend, ran like a dream for 2 days but now the jumpind idle has come back. My cars on gas too though. It seems if I get petrol running smooth, then the gas will run crap or vice versa. Can't get both running smooth at the same time. It's a nightmare :rant:

clean your throttle housing and idle control valve before touching anything
we have numerous cars coming into the shop that run like s##t at idle and mostly comes down to just that.
i clean out mine every service on all my cars and they idle real nice and the throttle responses are great
most mechanics wont go out of their way to clean a throttle housing unless asked to make the effort
..time is money and they can make more money by spitting out more cars

how do you do that?

Turn the idle screw on your throttle body up to the desired rpm
I did this on my Rada and it's been great
"DO NOT TURN THE IDLE SCREW ON YOUR THROTTLE BODY"
THE ECU CONTROLS ENGINE RPM.

"DO NOT TURN THE IDLE SCREW ON YOUR THROTTLE BODY"
THE ECU CONTROLS ENGINE RPM.
I already knew that

"DO NOT TURN THE IDLE SCREW ON YOUR THROTTLE BODY"
THE ECU CONTROLS ENGINE RPM.

RIIIGGGHHHTTTT is that a fact.

The throttle stop screw should never be touched, it is the screw with a lock nut on the rear side but guess what, the air screw, or idle screw as some call it, was actually put there to lift or drop the idle speed, in fact the manual even gives you the detail on the correct process to follow to adjust the BASE idle

There is nothing wrong with "tweaking" the idle to get a better and smoother idle

RIIIGGGHHHTTTT is that a fact.

The throttle stop screw should never be touched, it is the screw with a lock nut on the rear side but guess what, the air screw, or idle screw as some call it, was actually put there to lift or drop the idle speed, in fact the manual even gives you the detail on the correct process to follow to adjust the BASE idle

There is nothing wrong with "tweaking" the idle to get a better and smoother idle

I just adusted the idle speed on my Wife's TH using the idle screw, seems to be idling better now (around 750-800) but still a bit rough.
I check the PCV valve and it's a bit dirty, I can't find any vaccume leaks (doesn't mean there aren't any)
Next step is to replace the fuel filter which is overdue, I'll try some injector cleaner and clean the TB/ISC housing.
If that doesn't help I'm leaning towards clogged injectors from running it on standard unleaded and not filling up until well after the fuel light comes on.
I've recently replaced the spark plugs on both sides so I doubt it's plugs.

Edit:
Cleaned ISC, PCV and TB, PCV was dirty but TB and ISC weren't too bad, now purring like a kitten at around 850rpm, I may drop the idle back a little but I'm more than happy now :)