Volvo: missfire 940 turbo l reg, crank sensor, answer mark

Question
hi thank you for getting back to me i have changed the crank sensor it made no diffrence .
ref the coil dizzy i meant to write the ignition coil and the distributor cap have also been changed  the codes that came up according to the mechanic said hot wire fault or curcuit idle control or curcuit and an ignition trace fault the mechanic said he suspected crank sensor or curcuit
at tick over the c/0@ideal was 0.01% hydrocarbons@ideal was14ppm
c/0 at 2800 was 0.01 hydrocarbans was 7ppm  
hope this can help
thx mark
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Followup To

Question -
hi i recently bought a 940 turbo on a Lreg it has a missfire between 1000 and 2000 revs then it clears but with it being auto its a nightmare .i have had it on a crypton tuner and was told it was the crank sensor showing 5 traces instead of 4 when hitting this amount of revs i have changed that still same .
also its had coil dizzy cap leads plugs the ecu has also been changed abs changed servo auto box changed im banging my head up the wall now i even spoke to volvo frank taylors in hinckley they say they dont know what it is either .
lots say they will check it out at £40 an hour but it could take 6 7 hours and if they dont find anything i still have to pay any advise or help would be greatfully recieved thx mark

my phone number is 07742277255 or if you can ring me ill ring you straight back thx mark

Answer -
Mark,
Crank sensor showing a bad trace. That sensor tends to go out on occasion, and also has been updated to later design. I would say that if it is showing bad go ahead and change it. I do not know what you mean by a "coil dizzy". I have seen in the past where a small dent in the flywheel window plate, has caused a poor running vehicle. Can you read any codes in the control unit? If yes follow those and see where that leads.

Answer
Mark,
Are you planning to have the circut you mentioned check out? I am not sure of the circut you mentioned. It may not be something in the U.S. market. Anything done to the car that lead up to this problem? Your H/C C/O reading seem to indicate that the engine is not missing. Are you certain that it is missing and there is not another problem? Like a loose of power? Have you tested the injectors to see if they are all firing at higher speed, see if all the wires going to the injectors are tight... Are the plug wires all good? Maybe at higher RPM the wires break down, causing a miss.