Rough Idle at 900 rpm
 

Hello everyone! I'm very new to this forum*1st post* but I was wondering if I could get some opinions on the probblem I'm having with my 240. When I turn it on, I immediatly need to rev the engine to avoid stalling. After 5 minutes of this, it will idle @ 800-1000rpm, but its really rough. Someone suggested the intake manifold, someone else suggested AI valve being stuck. Has anyone had issues with their AI valve?

Thank You!

ps - think looks like a great group

seems like your motor needs to warm up before it idles properly... there are a couple things you could check... it could be the TPS sensor, MAP sensor, AIC sensor, or the IAC or it could be the throttle line needs some WD-40...

When was the last time you gave it a good tune up? It's odd that your car starts running better after 5 minutes though. Either way, it couldn't help to check your plugs, wires, injectors and such.

Good luck,
Matt

Check the basics first - plugs, wires, even a dirty air filter...

I'm thinking maybe your throttle plate is pretty dirty, causing it to stick to the inside of the throttle body. Since you to have to rev right after starting the engine up, this seems like a possibility.

Can't help you with the AIV question... I'm sure an S13 owner will answer that.

Questions: Did you just buy your car, or have you had it for awhile? Was it running fine, then all of a sudden this happened? This info might help others diagnose your problem.

Oh - and welcome to the boards:thumb:

I can't wait for jyjnx's faq, lol.

Alright, lemme try my best.

Clean your Throttle body, it's probably not helping, take off the intake plastic and use carb cleaner to clean it out. check yoru air filter while you are at it

Bad Idleing can be from several things. How old are your plugs? Wires? Do they look like they are in good shape?

Fuel filter could be clogged as well, when the car is cold it could be fighting to get through, pick yourself up a 91 300ZX fiel filter and pop that in. Search the forums for how to install it, I posted a walkthrough.

It's probably your AIV. MY best advice would be to remove it completly, unless you have smog, in which case you should take it out and clean it, then put it back in. Check ********** and under technical there is a AIV removal sticky, that will teach you everything and show you how to clean/remove it.

Could also be your Cat, could be clogged and inneffective when cold, but when it heats up it's fine.

Hope that helped.

Dr.

Uh, he means cat like "Catalytic converter"... not your kitty :D

I had the a similar problem. Fuel filter replacement worked for me. I just bought a new OEM one for $8. Labor is easy as pie.