bucking like a bronco under hard acceleration

[Innervations]

I have a 1994 540i automatic. It runs perfectly at idle and under normal acceleration but if I put the accelerator down all the way the revs start jumping between around 3,000 and 3,500 cycling about twice per second and the jerking is quite violent. It does not seem to matter if the engine has been running for some time or only just warmed up. Mechanic thought it might be the flow sensor on the air intake and replaced it but this made no difference.

Any ideas?

[genphreak]

You need to check it for recorded codes (it will have them) and probably tell you the fuel pump is delivery system is faulty.

Off the top of my head it could be the pump, fuel pressure regulator, filter or even the injectors and probably many other things.

[Innervations]

Thanks. I will check the codes and get back to the forum.

[shogun]

In case the car is US specification, you can make a stomp fault code test. See details on my website how to make a stomp test.