im not sure what it is but here's my situation... i was driving one day and when i stopped at a stop light i noticed my car's idle was really low.. like 500. anyways... it has a rough idle when i start up the car... and when i step on the gas while idle... it hesitate to rev up... i just gave this car a tune up last week! when i drive the car it hesitates to go... it feels like there's only two cylinders functioning... can someone help me? any clue? need more info? what kind? HELP!

 

Have checked your compression?

 

well no.... when i did the tune up i used RESTORE hoping it would do what it says it does... ya know?

 

Maybe your engine is to messed up in order for it to work.

 

its either your your sparkplg or spkplg wires same thing happened to me. unplug your wires and check'em, dont worry nothing is wrong with your engine if its what i think it is, it just feels like your missing a motor mount, i know, its a scray feeling
word of advice if you didnt use NGK sprkplgs use them next time.

 

My first thought was...oh, did a tune up. Now it's not running right. Check your work. Go back over everything you've done.

 

It had a rough idle huh? ...could it be your aiv unit? That might be the cause for the wierd idling. I think there is some thread on here that shows how to disassemble it and clean it out, that or you could check your maf and clean taht out as well.

 

AIV can be eliminated. apparently all it does is vent air from the intake on starup to warm up the cat. when it gets clogged it can let exhaust back into the intake. you can get a plug for the exhaust manifold from nissan or whatever co. if you have headers. also get rubber caps for the solenoid vacuum lines. might not be the real issue bit its simple and eliminates one possibilty.

 

i got a 1990 240 coupe, and im experancing basically the same issues, i've just done a tune up ( changed oil 10W40, oil filter, wires, Distributor cap and rotor, spark plugs ( NGK ) Etc ....

and when i stop at a light i idle at about 500rpm and the damned thing sounds like an old choppy V8, and the whole car is shaking.

i checked into everything that was stated in the forum, and went out and checked it out, it seems that the AIV line is cracked off of my intake unit... but it dosent make a diffrence if i plug it or not.. so im no quite sure if that is the issue...


any thaughts?

Any Sr Swap suggestions are welcome

Ohh and i changed the cat to also see if that was the issue...

 

could be overheating, that happened to me. i had my radiator checked and all the hoses i had some leakin and when i'd come to a stop the temperature would shoot up.