engine idles high after cleaning connectors

[Quark]

alright guys, hopefully someone can help me. Here's the deal.

I cleaned the connectors to my TPS, Idle switch, maf, aac, iaa, and my engine temp sensor. I didnt use solvents or anything so I know they are making contacts. The engine temp sensor was corroded, and one connector on the maf too. Sometime my car would run like crap and i'd jiggle the maf connector and car would be good.

anyways, I accidentally moved my tps in the process but I now have it set correctly with it reading .500 volts on closed throtle.

ok, so I think my aiv valve is broken cause my car doesnt idle up on cold starts. but besides that, when the car is cold, it idles nice at 800 rpms. when it warms up, it idles up to 1500 rpms.

now, when i drive, if im coasting past 15 mphs and drop it in netral, the car idles at 800rpms, but when i come to a stop, the idle rises to 1500 rpms again. its driving me nuts, something is telling my ecu to fricking open up the aac valve up.

someone please help me.

oh, and I also jiggled the temp sensor on the radiator hose just to see, but that wasnt it. and if I disconnect the aac while idlen, the rpms drop to normal. also if i disconnect the engine tempsensor it drops to normal.

I guess keeping things clean is NOT always good, cause my car was running pretty perfect before i went and cleaned corroded connectors.

HELP Me !!!!

THANKS.

oh yeah, its a 1990 240sx with 140k miles with a rebuilt head.

[Quark]

anyone?

I tried searching but its only for high idles, i checked them but what baffles me is the part where if im going more then 15 to 20 mph and i drop it to neutral, my car idles fine, but its when im at a stop light when it creeps up to around 1500 rpms.

[droll]

Did you put dielectric grease on the connections? If you clean them real good after they have aged, and become curroded, the metal tends to end up slightly smaller. Thus, creating loose connections. If it was working fine beore I would think this to be a good place to start.

[NISTECH]

disconnect the battery for a couple of hours and then recheck it. Doing this will clear any self learned values.

[Quark]

i didnt put die electric grease on my connectors, but I DID put a tiny bit of silicone grease cause thats what one of my mechanic did for my old maxima. so im pretty sure its not bad connections.

disconnecting the battery for couple hours will reset the ECU values? ive disconnected it for a few minutes and resetted the ECU by going from mode III to mode IV, just like it says in the FSM. Then I checked it for errors and came up with 55. Im going to try disconnecting it over night tonight though, just incase i didnt clear something?

[Quark]

ok, so i disconnected my battery overnight and fired up my car in the morning. The usual happend. idled at 800 till it got warm and then the idle creeped up to about 1500 rpm again. and once again, driving it and coasting in neutral past around 20 mph, the engine idles fine.

im wondering if its something to do with a speedsensor or something?

[NISTECH]

I am wondering if it is still your tps. wit the car idleing at that 1500rpm loosen the screws on the TPS so you can adjust it. try rotating it counter clockwise very slowly and see if the idle drops back to normal. if it does play with it till you get it right to the point the idle cuts down then move it a hair more. this will get it where it needs to be. If when you rotate it you get to the maximum counter clockwise setting and it still is maintaining the 1500 rpm idle,the TPS is not your problem. Shut the car off and reset it to the .5v setting you had it at. Do this and post back.

[Quark]

hey Nistech, i really appreciate you trying to help me out. Just wanted to say thanks.

Ok, so I turned the TPS counter- clockwise all the way while the car was idleing at about 1500 rpm and the rpm's didnt drop or anything, but just for kicks, I turned it clockwise, and the rpms started to drop to normal and stayed at the correct 800 rpms. I wasnt sure if this was good for the car or not, so I just re-calibrated it to .517 volts on my Fluke DMM. Coulnt get .500 exact, would either go from .517 to .498 around there.

You wouldn't happen to have meant clockwise would u? but im thinking if it was clockwise, the idle switch would not be where it should be.

Thanks.

[NISTECH]

if the idle dropped it means you closed the contacts in the switch. turn it clock wise just till the idle drops to the lower rpm. lock it down and check your voltage on those wires. It wont hurt the engine at all.

[NISTECH]

Yes I was trying to figure out which way you needed to turn it in my head I could have been back wards. but either way it wont hurt your engine. if you had an automatic it might of made it shift a little different. but not hurt it.

[Quark]

hmm.... So i turned my tps almost all the way clockwise to get my idle down, this setting left me at about .250 volts. This seems kinda low.

I know that there is another post with the exact same symptoms as me but the dude just said that one day, it started to work fine. This was about a year ago, but I havent gotten a response from him to know what it was that caused this. here is a link to the other post.

http://www.nissaninfiniticlub....22263