Engine 'judder' / hesitate on acceleration. help!

Hello, I have a 1994 audi 80 sport, engine code ABK. & I have this problem.

The engine hesitates/judders on acceleration, at high revs it has no power, at low revs it judders & hesitates intermtantly. It feels like a diesel vehicle in the winter when the fuel 'jelly's-up'.

I recently changed the engine & that is when the fault started, so I'm pretty sure that its electrical. my new engine is exactly the same (ABK) but is from an L reg audi 100, my car is an M.

I kept the injection manifold & airbox to comply with my cars wiring & plumbing.

I have changed the temp* sensors & MAF sensor, the temp* guage does'nt work but it never did.

The 'cat' rattles so does anyone know if a damaged catalyst would cause this problem.

I am fairly certain that it is electrical becouse sometimes its fine.

Any help or advice would be greatly appreciated.

No idea what the hall effect module is, but I'll soon find out. It has a new distributer cap & leads. Thanks for your response.

Thanks for that but the hall effect module is on the car & it was working fine with the old engine so its not the problem. I'm decating, changing the exaust boxed (they all rattle) & leaving the lambda probe disconnected. I suspect that the old leaky & rattle exaust may be confusing it, & if it is'nt it needed doing anyway.

Proplems sorted!

I snipped the lambda probe wires, took off the cat & dug all the stuff out of it, & put it back on.

I guess it was the lambda sensor all along.