Author Topic: bad idle (Read 12058 times)

vatos_p · « **Reply #15 on:** June 03, 2008, 02:28:19 AM »

the ICV is the Idle control Valve , and most Idle issues come from it...Take it out and clean it with Carb cleaner ( or brake cleaner )
Also check the AFM ( temp sesor - and other parts )

edit : yes it is the part that connects the main hose ( from the afm - intake ) to the plennum intake though this silver round part..

swiss318is · « **Reply #16 on:** June 03, 2008, 03:46:07 AM »

yep. check the ICV.. sometimes i have the same thing... i think i have to get a new ICV..

ClodKing · « **Reply #17 on:** June 03, 2008, 11:24:48 AM »

I got a little confused because my service manual calls it an IAC. I wanted verify before I went spraying solvents into that part, ya know??

Another question for you guys. Did you use heater hose as a vacuum hose for that run (intake to ICV to rubber boot)?? Or did you have problems, and needing to get real vacumm hose.

Maybe I should just run some 5/8 steel or aluminum tubing along the longer sections...

ClodKing · « **Reply #18 on:** June 03, 2008, 10:26:35 PM »

I picked up a 2' length of 5/8 steel tubing. The small wall thickness they had was .049.... I know it's really thick for this application, but I want to see whether it will improve anything.

I'll post pictures, and results when I get the chance to bend, and install the tubing.

EDIT: And the tubing has GERMANY stamped on the side... so I geuss it was meant to be, hahaha

vatos_p · « **Reply #19 on:** June 04, 2008, 01:34:01 AM »

I use high pressure oil hose ( 200 bar ) for any case of problems...

ClodKing · « **Reply #20 on:** June 04, 2008, 04:21:08 PM »

Well I bent up the steel tubing, and shot brake cleaner through the ICV, and nothing changed.

So I started pulling spark plug wire while the engine was running.

#4-pulled wire, engine laboured then recovered, but idled badly.
#3-pulled wire, engine laboured then recovered, but idled badly.
#2-no noticeable difference in idle quality.
#1-pulled wire, engine laboured then recovered, but idled badly.

I heard sparking whenever I pulled a spark wire. And I saw sparking when I pulled the boot from the coil for #2.

I pulled the #2 spark plug from the head, and saw it was covered in fuel (it smelled like fuel atleast) and soot. Not a huge coating of soot either. It was covered in a film of fuel that was darker colored.

I did a compression test on the #2 cylinder, and it scored a 170-175. I didn't think that score was too bad considering the car has 266,000 kms... BUt maybe I'm wrong.

I am thinking maybe the #2 fuel injector is bad, or fouled (but I cleaned out the upper and lower intake when doing the vacuum/coolant mod).

Any ideas??

vonkamp · « **Reply #21 on:** June 04, 2008, 05:53:29 PM »

Quote

I am thinking maybe the #2 fuel injector is bad, or fouled

That would concur with the engine code 1222. I would change it.

Quote

From the Motronic pedal fault code:

1222 Lambda Control 1 This code is stored when the DME detects excessive
deviations in the air-fuel mixture (too rich or too lean) for longer
than 10 seconds. Possible causes: Fuel tank ran empty,
Incorrect Fuel Pressure, Injector valve defective or coked,
Engine Temperature Sensor defective, Secondary air leak,
Fuel evaporation control system defective, Air Flow Meter
defective and/or the combustion is being disturbed by
mechanical failure (Spark plugs,, compression,
intake/exhaust valves, ...etc.)

ClodKing · « **Reply #22 on:** June 05, 2008, 04:47:05 PM »

Okay well I have my coils coming in for the COP bracket. I will install that before I go for the injectors. Just so I don't go throwing money at the engine.

I went that route before, and ended up with an all new top end, dual exhaust, headers, and bunch of other crapola... Granted that would be nice, but I really need a car again.

Birdman16 · « **Reply #23 on:** June 05, 2008, 05:23:27 PM »

My 91 318is had the same problem when I got it. As for the rough running, I replaced, which may sound a bit much, every single hose in the engine bay. I also did a valve cover gasket job because oil was getting in the plugs and the car was only running on three plugs. I also did a full air plenum gasket replacement and every other place where an air leak could take place. Finally, for the idling problem if that doesn't work, replace the throttle cable. My car did run bad and stalled after revved and letting off the pedal. This I did before the hoses and the car ran fine.

Good Luck

ClodKing · « **Reply #24 on:** June 06, 2008, 03:38:13 PM »

The throttle cable seems pretty loose... I geuss I should replace it.

I have replaced the intake plenum gaskets with new, and replaced all hoses (both vacuum, and coolant).

I really think that the #2 plug wire is shorting out on the block. I think that's where the ticking sound is coming from. And my coils should be at my house in a about a week or two. So we'll see if that helps the problem.

I am really starting to think it's a sparking problem. I can smeel un burnt fuel in the exhaust.

I mean I can smell fuel comoing from the suburban exhaust, but that's an 89' V8. I'd expect that a 91' 4 cyl from BMW would naturally burn most, if not all fuel in the cylinders.

ClodKing · « **Reply #25 on:** June 13, 2008, 08:40:52 PM »

Okay, so I received my coils, and found out that they didn't come with the boots to bring spark to the plugs...

So I went and ordered the boots, an O2 sensor, air filter, and fuel filter.

I figure the O2 sensor will help bring down the richness of the afm, and plus at 266,000km, the car probably needs a replacement anyways.... same goes for the air filter.

The fuel filter should be changed as it is. I mean the lines are gonna get replaced, so the filter will need replacement aswell.

So I'll let you guys know how the coils, and O2, and air filter swap affect the engine idle. You just gotta wait until I get the parts. And I ordered those yesterday so it could be a while.

BMWManiac · « **Reply #26 on:** June 19, 2008, 11:24:00 AM »

What is the ideal idle speed? 1k?

Birdman16 · « **Reply #27 on:** June 19, 2008, 04:51:10 PM »

I see where BMWManiac is going. I just encountered the same problem wednesday when I put the car on the road. Here is the solution...

Next to the throttle cable where it connects to the mount on the plenum is a small nut surrounding a screw like bolt. This is the idle speed control screw. Loosen the nut (7 or 8mm) and turn to the right for a higher idle speed and to the left for a lower idle speed. I had the same ticking problem but have not gotten that fixed yet.

This will definately fix your idle problem. Be sparring with the turns as 1 turn is about 250 rpm.

ClodKing · « **Reply #28 on:** June 19, 2008, 05:23:39 PM »

Okay so I got my parts in today.

I installed the boots only, and the engine runs much better with the COP on there.

The check engine light is off now, and the car idles around 1000rpm.

I am not installing the other parts, because it is raining here, and I don't feel like getting on the ground.

And my car will not go over the 3000rpm mark still. My one buddy thinks it's the Throttle Position Sensor. He told me his dads escort had the same problem, and that fixed it. Do you think that changing the TPS is all that's needed??

I'll check out that screw though.

BMWManiac · « **Reply #29 on:** June 19, 2008, 06:17:25 PM »

It seems when i read a thread, I develop those problems! The car ran beautifully until on my way home, the engine sputters like misfiring and then will kick in fine...my idle bounces now....I just replaced the plugs, replaced the intake elbow, replaced the fuel filter, and did all kinds of maintenance....I guess I'll try cleaning the ICV