Hi Guys,

I have just purchased another Tr Magna se auto 4cyl

It has a very rough idle when put into drive when in reverse its also bad but in park its fine

I have a owned a couple of manuals and they never had any idle issues but these auto equipped magna's seem to have this problem any advise on a fix guys?

Also whats a good oil to use on the magna its done 295ks.

Cheers
Mark.

engine mounts is the most commin cause

other than that a good tune up

Could be a few things.
First and easiest would be check the throttle stop screw, its a screw ontop of the throttle body.
Screw it out raises the idle and screwing it in lowers the idle.

But with that many k's, chances are the ISC is buggered. Its on the back of the throttle body (the side of the firewall) Disconnect the cables from it and chuck in a new one.
My one was stuck closed so it would always idle at like 400 wanting to stall in D.

How rough is rough? if its wanting to stall because its so low, it could be those things.

If its just rough but at the right rev range, just give it a service (new oil/plugs/filters)
Maybe oils old and valves are bit sticky.

Could be a few things.
First and easiest would be check the throttle stop screw, its a screw ontop of the throttle body.
Screw it out raises the idle and screwing it in lowers the idle.

But with that many k's, chances are the ISC is buggered. Its on the back of the throttle body (the side of the firewall) Disconnect the cables from it and chuck in a new one.
My one was stuck closed so it would always idle at like 400 wanting to stall in D.

How rough is rough? if its wanting to stall because its so low, it could be those things.

If its just rough but at the right rev range, just give it a service (new oil/plugs/filters)
Maybe oils old and valves are bit sticky.

Hye dude thanks for ya reply the throughout the rev range is good just when u come to a stop it idles and everything shakes and rattles :cry:

Injected or carburetor?

It's rough in gear because the box is putting load on the engine. Try turning the steering wheel at the same time and watch the idle get rougher as the power steering kicks in. I bet it's a low idle too. If the idle is dropping when in gear its probably either/or both the ISC and the ECU. There's lots of threads on this.

I reckon the manuals could be just as bad, it's just that manual cars are always in neutral or have the clutch in when at the lights.

Umm, I'd go with engine mount issues firstly. An easy check is to pop the bonnet and change from D to R (foot on brake of course lol), you should be able to see if the engine rotates. If it moves much then it's your mount.

Another common problem can be the ISC motor. From what I've gathered this would effect it when the air con is on also. So if in P or N and the aircon is put on and the revs drop, causing the shaking, then the ISC motor is a good bet.

Also I have heard of some ecu's having a capacitor leak causing problems with the idle, although from memory, this causes poor idle all the time so I don't think it's your problem.

Yeh a good start is definately the engine mounts... if your idle speed is ok (750 +/- 50rpm) but still rough, check your hall sensor in the distributor. These things cause alot of dramas in 2nd gens... they wont correctly adjust the ignition timing for idle, making the engine run rough as guts.

if its efi pay mitsubishi 50 dollars to make sure all the sensors are in alignment and they also diagnose what the prob is. i had super high idle. was because of isc but it was replaced 4 weeks ago from one from bursons. if it is your isc pay mitsu the 240 for a new one not a rebuilt 100 dollar one from bursons.

if its efi pay mitsubishi 50 dollars to make sure all the sensors are in alignment and they also diagnose what the prob is. i had super high idle. was because of isc but it was replaced 4 weeks ago from one from bursons. if it is your isc pay mitsu the 240 for a new one not a rebuilt 100 dollar one from bursons.

Ummm.... the isc is about the only major sensor that can be aligned i think. :confused:

Umm, I'd go with engine mount issues firstly. An easy check is to pop the bonnet and change from D to R (foot on brake of course lol), you should be able to see if the engine rotates. If it moves much then it's your mount.

Another common problem can be the ISC motor. From what I've gathered this would effect it when the air con is on also. So if in P or N and the aircon is put on and the revs drop, causing the shaking, then the ISC motor is a good bet.

Also I have heard of some ecu's having a capacitor leak causing problems with the idle, although from memory, this causes poor idle all the time so I don't think it's your problem.

Hey Tommo,

Mate thanks heaps for you suggestions with what the problem might be can you tell me what is a ISC and how much one will cost? and how much would it cost with labour to replace.

Thanks Mark.

from mitsu is 240 supplied and fitted. it is a thing that extends a little pointer thing to regulate the amount of air which raises and lowers your idle. sorry its not that clear.

for sensors i was talking about making sure tps is in the right place the timing is correct. also mitsubishi have a tester to test that your ecu is working correctly