Idle Adjustment Screw is Screwy

[2nissan240sx]

Hello all, I am a noob to this forum. I have a 90 s13 body with a 92 ka24de and a manual tranny. I am having problems with the idle. With the idle adjustment screw in more than half way in, when the car (http://zilvia.net/f/#) is cold it will start for a few seconds and then die, unless I give it gas. (Know that I am in an area that is still in the 70s at night in November.) It also wants to stall when I come to a stop. At least until it warms to normal operating temp. When warm it is fine. I have noticed though that if the screw is more than 3/4 open, it doesn't do any of this. Also when I disconnect the tps harness and try to adjust the idle, it will not adjust below like 900 rpms. So what do I want to know? I would like to know if it would be ok to drive the car with the screw open like that? I have heard that if you do that it could hurt the engine internally. Is this true and if so what can it do? If I can't drive like that, what would be my best route to fix the problem? Thank you for any help that you can give me.

[davirene]

Im no expert....but I do have alot of hands on experience.... First off running at high idle will mainly hurt your gas milage and of course it will cause more wear and tear but will still take years to notice...

Second...you should go though and do a full tune up or have one done...your throttle bottle could have alot of buildup causing your ecu to misread...your MAF could be going bad or be dirty but cleaning everthing first will start showing you what might be wrong?

Always check all your wiring and connections making sure there clean and not rusted or full of build up...most 240's have wear and tear and a quick glance wont show problems

I recently took my valve cover off and found a broken vaccuum line in the back...my idle is better now....I also cleaned my plugs and checked my wires....

http://i2.photobucket.com/albums/y14/davirene/1012091658b.jpg

[Sileighty_85]

Vacuum leak

[iambape]

^^^ cosign.

theres a leak somewhere. check all the tubes that are connecting from engine to intake.

[Bigsyke]

Doubt it;

If the car has an auto ECU it will idle high with the TPS disconected.

The TB stop screw
TPS
Timing
IACV screw

Should all be adjusted at the same time. There is so many variables that will cause these symtoms I couldnt even start.

[93nismo]

i enjoy people who just assume things and attack the idle control. you probly have a damn vacume leak. dont mask the issue and then have to fix more then one thing.

with an auto ecu itl idle high then drop to around 750 like it should. my car has that. your car idlein high isent really bad for the car. not really good either, think of it this way. it idlein higher is makeing it work harder then it needs too.

i dont claim to be an expert but sometimes when looking at things you answer your own questions

[iambape]

ive had this problem before.

i would turn it on let it idle for 2-3 mins. if i dont gas it, it will die. but after driving for 5 mins it just stayed at 750 for me.

i check my hose connecting from engine to intake and problem was it had a rip. got it changed and wham! runs fine now.

[hardest240owner]

wait if you have an auto ecu on manual tranny idle will rise to 1500 when you come to a stop then go back down ?? mine does this then down anywhere from 750 to 900 rpms and just fixed a vacuum leak so it runs better but it is normal for it to do this then? i have a dual cam auto ecu