M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Electrical => Topic started by: NO_CARRIER on June 30, 2010, 01:53:45 PM

Title: m42 surging/bogging problem
Post by: NO_CARRIER on June 30, 2010, 01:53:45 PM
1992 318i

First off, does the stomp test work on e36's?  or only e30's?

So this bogging started this morning.  It does NOT only happen when cold, it does NOT only happen when the engine is warm, and it does NOT only happen when starting from a stop-light, and it does NOT only happen at certain engine speeds.

I already checked for vac leaks.

At any engine speed, or vehicle speed the engine will suddenly bog and surge once.  It will happen at 10km/h or at 60km/h.  When coming to a stop, the engine died once.  Otherwise is idles at around 1100rpm then slowly settles properly at around 750rpm.  (similar to when the engine is cold).
Title: m42 surging/bogging problem
Post by: jscribble on June 30, 2010, 02:03:33 PM
Idle control valve? I'm e30, but cleaning mine out solved my floaty idle.
Title: m42 surging/bogging problem
Post by: NO_CARRIER on June 30, 2010, 08:54:28 PM
Should be the same thing no?  Still an m42 engine.  In either case, idle is fine usually... only after coming to a complete stop after accelerating for a while it might die.  

So here's some weird symptoms now.  On my way home today the check engine light came on intermittently, on and off.  Usually when it would bog the CEL would come on.  

I took off all the hoses and cleaned them out, I found some large holes in two of them so I replaced them or cut them where the hole was at the end (where the clamp was) and put them back on.  Now the CEL is on all the time.

For the record, the stomp test definitely does not work for my car.  Tried it a tonne of times when I bought the car 10 years ago, and still today it's not working for me.  And where I am is a holiday tomorrow so I won't be able to get it scanned/read until Friday at the earliest.

So I found two other interesting things... I went to check my spark plugs and surprised to find that cylinder 2 was full of oil, and cylinder 3 had some oil at the bottom as well.  So looks like it's time to change my valve cover gaskets + o rings.  Does anyone have a detailed DIY on doing this on the m42?
Title: m42 surging/bogging problem
Post by: jscribble on June 30, 2010, 09:05:10 PM
Assuming the stomp test is correct for your car, it could be that the throttle position sensor is not reading wot, thus not reading each "stomp".

Lifted from bf.c:

If your check engine light is on, click here (pre- '96 only)!
If you have a pre- '96 (OBD1) e36, this trick will work to tell you why your CEL is on. It will even work on e30s:

Turn the ignition on (not the engine, just ignition). The bulb check will come on. Quickly press the gas pedal all the way down and lift all the way up 5 full times. You have to do it quickly.

If you did it right, the CEL will flash once and go out. Then it will begin flashing the fault codes. It will flash in four sequences, representing four numbers. Each sequence will be separated by a short pause of about a second. For example:

Flash (short pause) Flash Flash Flash Flash (short pause) Flash Flash Flash Flash (short pause) Flash Flash Flash Flash (longer pause) indicates a code of 1444. Each number of flashes in each sequences represents the number in the code.

After the long pause at the end of the fourth sequence, it will repeat itself and flash the same code again, unless there is more than one code, in which case it will flash that code in the same pattern.

Aside from that, on the e30 valve cover and o-rings is as straight forward as could be.  Luck to you, sir.