Car stuttering at 5k

[Owend]

Hi chaps,
I bought an 02 plate 172 recently and lately the engine light has come on the dash and the car now seems to backfire/misfire over 5k revs. I was thinking coil pack but surely it would do it constantly as opposed to just over 5k? There previous owner told me he had issues with it before and was told it was the throttle body but he said it was then taken off and cleaned. Should I start by changing the throttle body? Any helps welcome.

Thanks in advance

 

[bloke]

crank sensor.

 

[Owend]

Is that the one which is 2 10mm bolts? Should I whip it off and give it a quick rub with some wet and dry to get it shiny again or just replace it? Will it throw up a code and tell me if it's the crank sensor etc?

 

[The_Pirate]

I'd say its more likely to be the HT leads, crank sensor usually lets the car start/run..

 

[Owend]

I've had dodgy HT leads before on my fiesta and they change with heat etc when the resistance grew, this misfire/backfire seems to be really aggressive.

 

[bloke]

crank sensor can give a 'hard cut' around 5,000rpm. can feel like a rev limiter, won't throw a code. chuck a new one on.

obviously get it plugged in first just in case but sounds like sensor.

 

[Owend]

I was going to describe it as something like launch control/rev limiter. I'll get the codes read Saturday and chuck a new crank sensor on Monday. Is there any particular one to choose or is it an eBay special job?

 

[bloke]

get one from euro, new type with blue plug. they do a facet one, have fitted loads of them without issue.

 

[Owend]

Cheers mate, is it just plug and play? Or splicing wires etc?

 

[bloke]

comes with two heatshrink/solder connectors for the new plug.