My 2001 2l petrol 626 sport missfires when it reaches 2500 rpm. up to this point it is fine and once past this point it is fine, but at 2500 rpm it starts to miss. I have changed leaky ht leads but the problem persists. (the revs dip at the 2500 rpm mark and the dip is very noticeable, esp when driving). any one have any ideas where the problem may be. im thinking TPS sensor?
I have put up with this for 2yrs now and its time to fix it, any ideas anyone.

 

Check all your engine grounds, roommate had a severe miss on his old BMW 316i that was due to a severed ground from the block to the fender, reattached and all was ok. You can even try your own jury-rig one to test, just use a jumper cable from a good solid bit of the engine to the negative battery post and rev it then, if it works you found your problem. Always try cheap and easy fixes before jumping to the expensive hard ones first Also welcome to the forums!! If you could fill out your signature so we know what car you drive, judging by your use of the word "HT leads" (spark plug wires for us US folks) your from either the UK or the Commonwealth, make sure you put the year your car was built and not the plate registration that is used in the UK. THANKS!!

 

thanks for the quick reply, yes I am in sunny U.K. will check earth cables as suggested