M50tub25 acceleration issue????

[Jnielsen]

Hi everybody. Wondering if anybody else has experienced the same as my problem here and what the solution was of course!

I just changed my engine to a newer m50b25 vanos since the old one was very worn out. When the rpm is going over 4500-5000 is starts to be a choppy acceleration all the way up to the limiter. Almost as someone is constantly tapping the brakes. I have changed maf, cam sensor, crank sensor, vanos acctuator, ecu, knock sensors. All connectors checked other sensors checked and found ok. Plug connectors are ok as well. New spark plugs, coils from old engine which didn't have this issue.

It pulls fine and hard but it's kind of cutting out. Injectors has been to injector tune and everything worked before the swap. The new engine that has been installed and was from a running car, "only" had 100.000 miles on it. It was running perfect, it is now just not above 4500-5000rpm.

Any ideas?????

During the weekend I will change the wiring loom as well as I have a spare from the new engine.

Regards

Jannik

[M3Pete]

Fuel pump?

[Jnielsen]

Hi,

Nope, not the fuel pump. The connectors inside the the plug for the speed sensor on the diff was not fully attached. So when at speed and above 5000 or so rpm, it would disconnect the plug. Fixed it and it has been running fine all day at the latest event:)