Hi

I had the problem that the car would need three or four attempts to start before firing up sometimes when hot but was quite rare, I had a quick look at the crankshaft sensor and the wires were so bare I was amazed it worked at all, so bought a cheap Delphi one for £20 rather than £156+vat from dealer and when I fitted it, it was worse than before, now it wouldn't even start and now the engine light was on with code on scanner PO335 crankshaft position sensor circuit A, so took it off and put old rubber ring off as it was stopping the sensor from going in all the way and now it starts but cuts out a few seconds after as if I've turned off the ignition and PO335 keeps coming up on scanner even when cleared.

Can I have bought a dodgie sensor? As Delphi are usually a good make, maybe Hyundai coupes are not good with aftermarket parts?

Can't even put the old one back as it was so brittle it literally broke into bits in my hand as I was pulling it off.

Any help would be nice thanks.