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Old 03-16-2019, 03:23 PM   #1
Join Date: Nov 2018
Location: Kentucky
Posts: 25
More Running Problems with my E30

So I thought I got the 220k m20 sorted out, but turns out it was too good to be true. I recently just replaced the Throttle Position Switch, as my car was idling really high. She now idles at the proper RPM but I do notice a small stumble or hiccup every few seconds or so when sitting at a stoplight. The RPM does not move but I can hear and feel the car misfiring. Also, when the car is not cold (Could have driven the car 5 mins, not even up to temp) it has a hard time starting. It fires right up in the morning but I will have to crank it for 5-8 seconds for it to finally stumble to life. I don't have much experience with these cars but it smells like its running rich and feels a little down on power possibly? I have replaced every vacuum line and gasket on this engine that has to do with the intake. Could it be a fuel problem or a sensor malfunction? I have done some digging on the internet and it sounds like it could be the fuel pump, filter, or injectors but I'm just not sure. I also adjusted the valves to 0.010 inches myself, but the valvetrain still sounds quite noisy. If you blip the throttle at idle, it will bog down but then try to rev again. Hard to notice when I am driving, however.

Side Note: the spark plugs have also been changed, but the wires are not the right ones for this car. Some brand called Import Direct.

Last edited by angelfire; 03-16-2019 at 03:29 PM.
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Old 03-16-2019, 05:09 PM   #2
325e '87
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Join Date: May 2017
Location: SC
Posts: 328
What year is your car?

These engines are a far cry from anything made in the last 20 years if you’re comparing how they run. They take a while to start when warm, you can smell gas, and they’re not hyper responsive off idle at cold operating temp. The fuel injection system is like a calculator from 1992.

That being said, they are among the most satisfying engines the world has seen. Get the ignition system up to spec, use 20W-50 oil, and clean the injector tips/intake mani/throttle body, good coolant temp sensor, fuel pressure, O2 sensor, and drive it hard for 1000 miles.

The more intimate you get with her, the more you get. These engines are special, but you need to get to know her at this point 30 years after she was made....
My son has the 1987 325e, 2 door, 5speed
I daily the 1989 325i, 4 door, 5speed
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Old 03-16-2019, 05:15 PM   #3
Join Date: Nov 2018
Location: Kentucky
Posts: 25
My car is a 1987 325is. I recently just cleaned the IM and injectors but not a deep clean. Iím starting to learn that these cars for for sure not like my Honda Accord haha. I did test the coolant temp sensor and o2 sensor and they were fine. I did notice however that if I cranked the car for about 3 seconds, before it would start, then turn the key off and then crank it again, it would fire right up. Iím guessing the issue is fuel pressure related. Do these cars prime the fuel pump when the key is just ďonĒ? I canít hear it running
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Old 03-16-2019, 05:40 PM   #4
Todd Black 88
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No they dont
Originally Posted by codyep3 View Post
I hope to Christ you have looks going for you, because you sure as fuck don't have any intelligence.
2001 silver/Blk 325 cabby. SOLD
1988 Blk/Blk e30 factory wide body kit car SOLD
1992 DS/BLK 325 m-tech II apperance pack cabby SOLD!
2002 325xit Sil/blk. SOLD
2012 328i xdrive touring. Wht/blk. SOLD
2009 135 cabby. monacoblue/blk leather SOLD
2007 Z4m coupe. Silver grey/black/ aluminum. 1of50
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Old 03-16-2019, 08:16 PM   #5
Join Date: Nov 2018
Location: Kentucky
Posts: 25
I think confirmed it. Itís a fuel related issue. I just tried to crank it over (engine was about 60 degrees C or 140 degrees F) but stopped before it fired up, aprox 3 seconds of cranking. Cranked it again and it fired right up. Pushing on the gas pedal doesnít change a thing. Iím going to have the fuel pressure tested as well as the vacuum system smoke checked on Tuesday. I feel like fuel would
Be the only reasonable answer
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