Misfire! Having a mare!

[StorminNorms]

Hi, this is my first post so bear with me guys.....here goes.
Got a 172 ph2 with an annoying misfire every time I accelerate over 3.5k-4k. Had new platinum plugs when serviced last week. Had the gearbox earth strap replaced after an engine mount went and damaged it. Swapped to new blue crank sensor along with wiring mod. Had 2 diagnostic runs at my trusty local garage and at Renault, found absolutely nothing. Changed inlet gaskets as they forgot when serviced (Doh!). Cleaned throttle body and sensors that plug into inlet manifold. Really struggling for ideas now and don't want to leave it with the local autosparky as he charges a fortune per hour.
Any suggestions welcome as I've been scratched my head so much I'm losing hair lol. Cheers.

 

[TheEvilGiraffe]

Did you use the right plugs ? Was the misfire present before the swap ? There is a choice of 1... Search will find the right one, but it's NGK PRF10 or something like that..

Misfires are to do with ignition. Sensors and inlets have nothing to do with it 99.9% of the time.

Check:

Plugs, HTs, coilpack, injectors.

 

[StorminNorms]

Yes mate, new plugs were the NGK ones, garage rang me to double check. Now you mention it the misfire started when the mount went (car stalled, very big lurch and the earth strap got damaged, wouldn't start) when the earth was replaced is when I noticed the autosparky had also (without telling me:S) modded the wiring for the new TDC sensor at the same time. I just bolted it on and plugged it straight in when I swapped it for the old black one and it seemed fine? I don't really fancy buying a new pack and leads if his fiddling is the cause. Is there a way to check its not the modded wiring at all? Thanks

 

[TheEvilGiraffe]

Find someone nearby with a 172 and swap a couple of bits over to eliminate the problem ?

 

[StorminNorms]

Yep, I think I might have to, I know there's a couple of 182's in my area, are coilpacks, leads and TDC sensors the same as the 172? Either that or just bite the bullet, buy all 3, and hope its 1 of them. It'll still be cheaper than the autosparky I used lol. Thanks for the advice man :cheers: