Rough Idle

[Selecta]

Hey Guys/Gals,
I have a friend who recently picked up a 93 4banger for dirt cheap. Everything is cool with the car with the exception that when it idles it is extrememly rough and feels like it's going to cut out. However, you rev the car above 2k RPM and it's like the engine is brand new.

Any thoughts on this matter.

[Typhoonk]

Check for intake leaks.

Clean MAF, throttle body, idle air control valve.

Replace gaskets at throttle body, and idle air control valve.

Test the MAF.

Replace the coolant temperature sensor, and that green temperature sensor on top of the air intake plenum.

well that's my two sense. anybody else?

[Selecta]

Well my buddy took it in for an E-Test and it failed. They said it was the injectors or something.

[nAs]

hello people,
damn u guys know a lot of **** .. i looked like a dumbo standing there when the guy did a technical speech
so ya .. it failed E .. guy said that it could be the fuel injection or pistons ..
typhoonk, thanks for the to do list

[Selecta]

Hey Nas,
Are you still coming to the meet? Cause you can get more insight from the guys/gal there. Also when I go tomorrow to get my brakes done (if they come in today) we can have Ray take a look at it.

Cause I mean if it's the injectors or the pistons it should have trouble through the entire RPM range and not just under 2k...IMO

[csdude]

U, mine was the exact same way for 2 years. Rough at idle, clear as a bell at 2000.

If you read another topic on here, "not the fuel pump, other ideas?", you'll hear about how my '92 just shut down a few days ago and won't come back. I didn't think about it until you posted this, but now I'm pretty sure that the problems are related; in which case, the culprit is most likely the distributor.

[atlantamx3]

I would have to reference you to the following post I made on this topic:

http://www.mx-3.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=002384

This is VERY common with the SOHC models and has been the base of many discussions over the years.

[Selecta]

Thanx guys...I think the guy is taking it in to the shop to have it looked at and once we know what the cause is I will post it back up and let you guys know.