Surging idle/Misfire/No power (PLEASE HELP!)
 

First let me introduce myself. My name is David and I have a 1995 318ti OBD1 M42 car. I purchased the car about 3 months ago from a gentlemen who intended to give it to his son as a college car. The car has 240k miles but with a rebuilt engine with only 20k on it. The car hasn’t given me any issues until now and I desperately need help because I’m losing my f**king mind trying to figure out what the issue is. So here it is:

The car has developed a terribly rough idle, idle dips too low and the car dies. When the issue first began the car would have a dead spot in the throttle pedal that felt like fuel was being cut. As the problem persisted, now almost the entire rev range is a dead spot. The car has absolutely no power at all, dies, rough idle and is drinking gas like a 454 El Camino.

I don’t have access to a obd1 scanner with a bmw port so I have basically made educated guesses on what the problem could be. I have dumped too much money into it and do not want to keep guessing until i know for sure what it is.
So I have replaced:
-oil and filter
-spark plugs (inspected for leaking oil from valve cover gasket blocking spark plugs and there were no leaks at all)
-new throttle position sensor
-Unplugged o2 sensor to see if it was faulty, car still drove the same
-new camshaft position sensor
-cleaned ICV very very very thoroughly and verified that it is not stuck
-removed and inspected intake duct for tears, there are none.

So now I am frustrated as hell. I have narrowed it down to a few more options such as crankshaft sensor, but if this were the case I don’t think the car would start at all. Spark plug wires and the single coil pack, but those are super expensive and I don’t want to replace those until I know for sure they are faulty.
That old school large MAF sensor, but that appears to be brand new as it is the shiniest and cleanest part of the engine bay!

Any ideas?
Thank you! 😔

Change the MAF. My bet is someone cheaped out and got a crappy ebay one. If it isn't stamped Bosche, go out and get an OEM one. Ask me how I know.

I had the same problem. Culprit was a loose fitting IAC connector. Problem is that part is now impossible to buy new. So i used zipties to clamp it on TIGHT. Now problem solved. So check your IAC connector. There should be absolutely no play in it. 1 way to tell is have the engine at idle and move the connector around. If u have a change in engine note u have a problem there. Hope it helps.


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