No spark in engine when wanting to start.

[B5Mark]

We have no spark on my 2000 B5 S4, we got a vagcom test on it, the vagcom only had one fault code. communication between cluster and ecu not found. we replaced the cluster (because the immobilizer was acting up) and the crank sensor and still have not found the problem. could it be the ecu keeping the car from starting? any ideas? thanks.

[rguil]

You sure its spark?
Check all grounds, check crank position sensor via vcds. Could be tone ring of flywheel if you have lwfw Check ICMs
I actually had a ecu fry while driving and it wouldnt spark at all. just crank and crank and crank. it is possible. I could still connect via vcds however

Ecus are cheap at junkyards btw just be sure to find a compatable one

[Zba]

We have no spark on my 2000 B5 S4, we got a vagcom test on it, the vagcom only had one fault code. communication between cluster and ecu not found. we replaced the cluster (because the immobilizer was acting up) and the crank sensor and still have not found the problem. could it be the ecu keeping the car from starting? any ideas? thanks.

These cars didn't have immobilizers. Is this a Canadian or grey market car? If the immobilized was truly acting up (obviously if you really had one) then I think it's safe to say the immobilizer is still what's preventing your car from starting.

Fuel, spark, compression? You have physically verified all of this to be good or bad? Your last post you said You had spark and fuel and the changed your mind. Now this thread...

[zillarob]

I think it would be a good idea stick to your 1st thread on this to keep things in one place