Mis firing head ache

[Cup_Clio]

Lost for ideas now really.
my mis firing problems a weird one
ok with platinum plugs in it misfires constantly
with normal ngk plugs non irridium ( platinum ) it only misfires at the 5k kick or if u plant ur foot at low revs...
tried changing the plugs
tried a different coilpack
tried a map sensor
Added some injector cleaner into fuel today but doubt thats gonna do owt.
Not showing up no codes although today when i re tried some brand new irridiums it mis fired that bad the engine management light came on. I put the normal ngks back in and back o before. Only misfiring at 5k. Very strange one
Any help much appreciated

 

[Daniel]

Changed the HT leads?

 

[Cup_Clio]

no, ill try them this weekend. any other suggestions if not. Thanks

 

[marinemackay2003]

have you had a look at your injectors?

may be partialy blocked ect

woth a check after the HT leads

 

[henders]

Upstream/pre-cat lambda sensor. Get the codes reread just to check though as it will now be a lot easier to diagnose with the EML light on as it means that there is now a stored code. Hope this helps

 

[Cup_Clio]

ye, next thing im going to do is the ht leads, although ive a funny feeling its not gonna be them. its weird how it drives totally fine till it gets to 5k then it misses. not even drove the car running its best yet. says alot for them dosent it. ha