3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
Please excuse this noob if this is a previously answered ?. I just recently bought a 1984 BMW 318i. I have a wierd idle problem. It was idiling fine for the test drive and was idiling fine that night i bought it. I woke up the next morning to find that it did not want idle. I would start it and it would jump between 1200 and 500 or 600rpm. Usually after a min. or two the engine stalls/dies. Dont know whats wrong. Starts up fine and pretty sure it drives fine(all gears too). Please Help!!!!!!!!!!!!!!!!!!!!!!!!!
Looked it over and I've found a few hoses that where either cracked or rotten. I also realized that the icv dosent have the wire connector or any wire going to the prongs on it. About 3wks. later the idle was about 3000-3500.. I got all vacumn hoses and replaced all but one that seemed to look alright. I also cleaned the ICV put it back on and started the car. Idle was still just as high. . Then I decided to put the frayed wires on the prongs of the ICV to simulate the connector being there. It dropped the idle to around 1100-1000. I talked to a dealer and I'm gonna try and match up a connector I can use.
Couldn't get an actual electrical connector but i did mange to find two seperate connectors that fit the prongs on the icv and crimped the wires to the connectors. Put the connectors on and the idle was right around where it was earlier(1000-1200). But then after it ran for short while it started to surge(between 1300-800). Put a few more hose clamps on hoses that didn't have any and to my suprise the idle stuck at 2000. It stayed like that for a solid 2min. Then again started to dropped till it hit 1100 and stayed there for 4-5mins.But then right back up to about 2000-1800. I plan on ordering the MAF boot, 1 more vac hose, and a fuel dampener i found leaking as it was running today. Anybody have any other ideas to as why the idle is high?????? I'm guessing a vacuum leak is no longer a possible problem since it's no longer surging idle.
Alright guys I'm in the process of taking a few pics of my engine to try to you guys out. In the mean time, besides the obivous vac hoses and the tb itself, where are all of the other places it could possibly have vac leaks. Anything would be helpful. I heard somebody say the fuel rail can have vac leaks???Can anyone back this up.
Have a look at the gaskets between the throttle body & ICV to see if they are leaking. The easiest way to track vacuum leaks is to get some carby or brake cleaning spray, and a nozzle (rather than a spray) and work your way around the various possible leak points with the engine idling and see when the idle changes. This is how I have pin pointed my vacuum leaks. Use caution when doing this to avoid setting fire to your engine bay.
Nice idea, Brettski... I would Grease the edges of any gaskets and see if it "sucks" it in!!
I wouldn't suspect the MAF boot as it would not make the engine "race"...
Could be a throttle sensor issue - Just clean everything you can get to !!
Eso es todo! Please press the "REP" button if you are happy with your response/answer...
I have a nearly similar problem as Furious '84. My BMW316i engine starts normally but when left in idle, it dies. It is particularly frustrating at road intersections and when slowing down because if i take my foot off the gas pedal it dies on me. I have put on clamps on all hoses, cleaned the ICV with kerosine and even put on a new gasket on the ICV.
The exhaust smells horrible with unburnt petrol and carbon monoxide probably.
The only thing i have not changed is the airfilter as i leave in a location with no BMW dealers or parts sellers
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.