Rough idle and hesitation in "drive" (auto)

1993 Lancer CC
Engine - 4g93
No mods.

So I bought a cheap car the other week and it's got a problem idling and taking off from a stop after warming up. It idles fine while in park or neutral, but as soon as I put her into gear, the revs drop to 300 - 400 rpm and the car shakes pretty violently.

When she's warm, and I try to accelerate, it's sounds like shes misfiring and is about to die and really sputters along till I get a little speed. Runs fine when I get some speed though.

Checked the spark plugs, and they seemed fine. Replaced them anyway, no luck. I'm thinking it may be a vacuum leak or something to do with the IAC, though I'm not very mechanically inclined as this is my first car.

Cheers,
Mos

Could be low trans fluid.
But i think sounds like you need to clean the throttle body, Sounds like its not letting in enough air into the throttle body valve, As causing the rough low idle etc.
I'm just guessing now but, That's what it sounds like.

Edited by InitialToke93, 10 July 2012 - 06:29 AM.

Cheers for the input. Replaced the trans fluid already and there was no improvement. I'll give the tb a good clean in the next few days and I'll look for any vacuum leaks.

Also, the check engine light doesn't come on, so there's no codes to help.

Thanks again

Clogged fuel injectors? Vacuum leak? Bad spark plug wire? IAC?

sounds like either vacum leak and or eletrical

I got the same problem op but with a manual 96 mustang. I change the air intake and now it idles at 500 rpm. The car was running fine before that. Im ripping my hair out.

Sounds like the the tb isn't opening open for the added load and then getting an intermittent signal. Can you check the throttle position sensor? Have you had the car scanned for codes?

Do you have the air conditioning on? And if so does this happen when it's off?

If it happens after you have been going highway speeds or above 40 mph, it could be your torque converter solenoid, just unplug it and see if it still does it. I just had this problem in my car. I'm buying a five speed next time.

Also, check your coil packs and wires.

Maybe your spark plug wires. I would also check/replace distributor.

Cheers for the replies guys, haven't had a chance to look at her yet, but my dads gonna come round tomorrow or Monday and take a look and go over the suggestions. She passed the safety check and got her registered today, so I should be on the roads next week hopefully. Watch out haha

Okay, update!

Spark plug/wire change seems to have fixed the stuttering on acceleration (took her out today for an hour drive, and no issues with that ) So I'm hoping that was all it was.

Only problem now is the motor was revving a little by itself. Something like vroom.... vroom... vroom... Stopped as soon I had turned it off and was gone when I started it again.

Thanks again guys, really appreciate it

Edit: Also, it only happened on the last 10 mins of the drive

Edited by Mosuko, 16 July 2012 - 04:46 AM.