S50B32 Euro not running clean.

[Mr. Horsepower]

Hi!

Got trouble with my S50B32 not running clean.

Engine has been sitting for about 6 months before I got her fired up in the E30M3. Cheating can only be felt when I floor it in first and second.

You can clearly hear it in this movie here:

http://www.youtube.com/watch?v=kFIa1vc_-_o

Have been to BMW and they could not find any fault codes that should interfere with the engine not running clean.

I have also changed the spark plugs, of course I used the stock "in"expensive NKG plugs. And it is still not running clean in first. I assume don't have all the HP eather.

You who got S50B32 in E30, if you start off rolling slow in first and put the pedal to the metal. Does the tires start to spin before you hit the rev limiter? Mine don't with 225/35 Toyo T1-R....
Even in WET it don't!

Going to the dyno on Saturday, so if I don't find out anything before that time I will probably see it on the dyno sheets. With no speedometer signal the curve drops drastic at about 5-6000 to rev limit. It just dives down.

The hesitation is felt best at first gear. Some say that it is programmed in DME to put aside torque in first. But DME does not know what gear I have it in. The gear shift switch is soldered together so DME thinks the car is in gear all the time. That includes the clutch line switch as well.

[sonnyqm3]

did you check all ur vacuum lines for leaks and check out ur fuel filter to see if its dirty. Also what fuel pump are you running, I had great success with the 36 m3 fuel pump, although i had to modify it a lil bit.. Do you have any exhaust leaks by any chance..

[Mr. Horsepower]

Vacuum lines is new and changed when the engine was out.
Fuel filter is new stock E30M3.
Fuel pump is new Bosch 044 in line so that delivers enough fuel.
There are some small exhaust leaks

[sonnyqm3]

fix the exhaust leaks,check ur o2 sensor and maybe the compression..

[Mr. Horsepower]

Exhaust leaks don't interfere with the engine running clean or not. The leaks are so small that it is only located with some condense water dripping from them. They can't be heard or felt.

Like I sad, the engine worked perfect when it was in the E36M3. I drove the car myself and it was pulling like a train. Can't say that the E30M3 does pull that much.
I assume I'm missing about 40-60hp.

[Mr. Horsepower]

Also going to check if the coils are ok. Simply check them in a dark room (garage of course) by taking off the cover and fire the engine to see if they throw sparks to ground.

[FredK]

What do you mean by this?

With no speedometer signal the curve drops drastic at about 5-6000 to rev limit. It just dives down.

You have a speed signal to the DME hooked up, right?

[Mr. Horsepower]

That if you don't have speedometer signal, you will get a curve like that.

I switched place om the two cables at the diff, and I think the problem is solved. There was not that much hesitation in first. Just a bit, but there was cable shoes on the sensor that was corrotion on. And there was also corrotion on the sensor points. So I'm gonna change the cable shoes and sand the contact points on the sensor.

[sonnyqm3]

what sensor shoes...

[Mr. Horsepower]

Speedometer sensor in the diff

[Mr. Horsepower]

No one that can help??

I have dynoed the car as well. No miss shaped curves at all. Did a pull in second gear, and then I got an uneven curve. Pulled 280 at the wheels.

I can also "fool" it. If I rev it up to 4-5000rpm rolling with not much throttle before I floor it, it is almost running clean the rest of the way.
But if I floor it from 1500rpm it is just cheating all the way...

Can it be the O2 sensors?

[jrdeamicis]

What are your AFR?

280 at the wheels? Thats sounding healthy.

[Mr. Horsepower]

Don't know the AFR :(

[Ray Smoodiver]

Talk to Ian Haynes, as far as I can recall, the ecu can cut power like you describe if certain wires are not hooked up. I don't want to throw out misinformation as i can't recall exactly what wires they might have been, but I remember him troubleshooting this exact issue.

Also, you're running a 5 Bar fuel system, yes?

[Mr. Horsepower]

All wires are hooked up right as they should be. If the ECU had cut power I would have seen it on the dyno sheet.

For example, if the speedometer signal is out the curve will drop drastic at 5500-6000rpm. And if the gear indicator switch is left unplugged it will drop around 40hp after 4500rpm or around that area.

I have a Bosch 044 in line fuel pump. That is capable of 500-600hp.