88 325 IS ..Saga continues!

[Zdaneman]

Ok Gents,

Need help or next suggestion on what the heck is going with this puppy! I don't mind spending the money but I want to get her right again! I'm close, I think.

Heres whats been done; all new parts .... plugs, 02 sensor, idle control value, fuel regulator, ECU, fuel injection gas lines, vacume line from fuel regulator to manifold, cleaned air intake box, air intake boot, checked all possible air intake locations, cleaned throttle springs, cleaned throtle body buttery fly value (most of this was very nasty), sprayed carb cleaner everywhere can't detect any leaks.

Problem: idle surge and check engine light flashing on and off

After ECU was replaced car ran perfect for 30 minutes of idling and 15 or so miles of driving. I drove to the Pentagon this morning and about a mile out of my 18 mile drive, after hitting a bump, the check engine light flashed on again!!! I pulled into the parking lot and the engine surged again not as high..750 to 1300 PRMs. Same stuff on the way home tonight! Doesn't do it all the time now, and surging spells are greatly degrated in the amount and time it speeds ilding high!

Engine sounds like she falls, or stutters at highway rpm say 2500 to 3000, but only once and a while. The ECU did help but its still not right! Is there a ground esides the one in the trunk, that one is rock solid! The engine is not throwing any codes...but is running rich on fuel!!! Is there a sensor or idle control sensor I still need to replace???I'm going insane here now....what the hell else can this be! If I was back at an SF Group I'd call in a nine line and blow her in place.......loosing me wits! Likely its something simple. Manual is no help either...I can quote it in places...Whats next???? I've also replaced the Alterator and have a new batter with new terminal conections.

Heck, I've fixed Ducati Race bikes! This is kicking my butt!!!!

Perplexed SF Officer sends!

 

[jrt67ss350]

The fact that it was running fine until you hit a bump makes me think there is a loose connection somewhere. Check your engine ground strap (runs from the frame to the driver's side of the oilpan on my car - under the airbox), check the electrical connector at the idle air control motor, check the connector at the airflow meter, check the electrical connector for the O2 sensor. You could also check the connector for the throttle position switch (underside of throttle body), but I doubt that's the problem.

My guess now is that this is either IAC motor or O2 sensor connector related. I'd put my money on the O2 sensor.

Just double check all of your connections - you are obviously very close!

 

[epj3]

The fact that it was running fine until you hit a bump makes me think there is a loose connection somewhere. Check your engine ground strap (runs from the frame to the driver's side of the oilpan on my car - under the airbox), check the electrical connector at the idle air control motor, check the connector at the airflow meter, check the electrical connector for the O2 sensor. You could also check the connector for the throttle position switch (underside of throttle body), but I doubt that's the problem.

My guess now is that this is either IAC motor or O2 sensor connector related. I'd put my money on the O2 sensor.

Just double check all of your connections - you are obviously very close!

I highly doubt that - I drove around for 2 days with NO o2 sensor and it actually nearly stalled, not surged the idle.

Remind me - what year and model is this car? Ever replace the crank position sensor?

 

[Zdaneman]

Mates,

o2 sensor is brand spanking new! Year is 88 325 is with 89K miles. Today it was starting to run as bad as before I replaced everything. I've got two cans of electrical connection cleaner spray...so you know what I'll be doing Saturday after duck hunting! Checking connections!

Could this be the throttle position swithch causing this?

I have not replaced the crank position sensor. How big a job is that? Is it internal or external on the motor. I'll check the book too...just wondering? This must be something simple...everything else is about brand new now! Any other suggestions??


Zdaneman sends

 

[epj3]

Mates,

o2 sensor is brand spanking new! Year is 88 325 is with 89K miles. Today it was starting to run as bad as before I replaced everything. I've got two cans of electrical connection cleaner spray...so you know what I'll be doing Saturday after duck hunting! Checking connections!

Could this be the throttle position swithch causing this?

I have not replaced the crank position sensor. How big a job is that? Is it internal or external on the motor. I'll check the book too...just wondering? This must be something simple...everything else is about brand new now! Any other suggestions??


Zdaneman sends

It's a 10 minute job, outside the engine. It's on the front of the crank where all the belts go to in the center. It's a magnetic sensor that counts the teeth - you'll see what I'm talking about if you look down in. Might be at the bottom of the crank on the M20, but I don't remember. It's around $50 - $100, depending where you get it. Check autohausaz.com before you go anywhere else.

 

[jrt67ss350]

Yes, crank position sensor on the 325i engine is at the front of the crank, right behind the crank pulley. You'll see the Hall effect pulse ring behind the pulley.

On the 325e, it's under the car mounted in the bellhousing.

 

[epj3]

Yes, crank position sensor on the 325i engine is at the front of the crank, right behind the crank pulley. You'll see the Hall effect pulse ring behind the pulley.

On the 325e, it's under the car mounted in the bellhousing.

I don't believe the late M20's and M30's were hall effect - there were two types, the one measures resistance, and the other generates a voltage pulse. (At least that is what my e34 bently says for the M20 and M30.)