1989 E30 325i - Stutters at Highway Speeds

[Breezeways]

My 1989 325i E30 has recently suffered a new problem. When driving at highway speeds (60+ mph) the car will often drop its RPMs and the check engine light will appear on the dash.

Here is a video illustrating my problem. I'm quite confused because in the description he states that he has changed both the DME fusible link and the crank positioning sensor. This is confusing to me because in this thread the posters give advice to check these two areas because they may cause issues.

Has anyone seen this issue and how did you go about solving it?

[dnguyen1963]

That sure looks like the engine is losing its CPS signal. Put in a known working CPS if you have one to see if the problem goes away.

[Breezeways]

That sure looks like the engine is losing its CPS signal. Put in a known working CPS if you have one to see if the problem goes away.

I dont. :/

I was planning on ordering one. I assume I should go ahead and place that order?

Thank you for responding.

[dnguyen1963]

Check to see if you have E30 fellows in GA that can lend you one before spending money. There are quite a few E30s in the GA area.

[Breezeways]

Check to see if you have E30 fellows in GA that can lend you one before spending money. There are quite a few E30s in the GA area.

I'm not in GA right now because of school and work. However, my dad is. I will ask him to try and find one. Can you suggest any short-term fix? I had to stay at 55mph on the drive to work today else it would cut out.

[dnguyen1963]

Try to clean the CPS then measure the distance to the toothed wheel. The distance should be 1 mm (use a feeler gauge). Make sure the bolt is tight and the CPS is not moving around.

[Breezeways]

Try to clean the CPS then measure the distance to the toothed wheel. The distance should be 1 mm (use a feeler gauge). Make sure the bolt is tight and the CPS is not moving around.

I plan to clean the CPS when I get home today. Do you know where I can find instructions on how to remove it? I couldn't find any information on it in the Owner's Manual authored by Bentley Publishing.

Yesterday, I checked the CPS and its wire. The CPS is tight and secure. Furthermore, the wire had no leaks or breaks. I think the action to take against the CPS is to clean or replace it.

What will the distance to the toothed wheel tell me?

[dnguyen1963]

CPS is basically a magnet. If the distance is off the signal coming into the DME will be incorrect and the spark might be cut off.

http://www.e30zone.net/e30zonewiki/index.php/Crank_Position_Sensor

[Breezeways]

Update: Tried to clean the Crank sensor. Failed miserably. I couldn't get leverage on the nut and it wouldn't turn. If you have any suggestions, I'd love to hear them.

Otherwise, father suggests that I take it to AAA and have them diagnose the issue. I'm almost certain that it is the crank sensor because the problem persists and it wouldn't start after the first turn of the key this afternoon.

[dnguyen1963]

What did you use to try loosen the bolt? You need an Allen wrench/driver to break it lose. Do not take your car to AAA. I doubt that they know how to fix an E30. Try to locate a local BMW mechanic.

[Breezeways]

Used an allen wrench. Space was so tight and engine was hot I ended up burning my hand quite a bit. Not to mention, I couldn't gain any leverage. I will try tomorrow morning.

[Breezeways]

Went out and recorded a video.

You can view the video here. Let me know if the link doesn't work.

[dnguyen1963]

Do you have a set of allen driver and a socket wrench? What you have should work. Flip the wrench around then use this technique to help you.

http://www.dirtrider.com/features/protips/141_1002_trail_tips_leverage_from_an_allen_wrench

[gart]

Go get yourself a allen socket set.

[Seawolf]

What's your fuel pressure reading, this could be an ailing fuel pump dropping pressure.