slight missfire hunting

[k13nay]

hi i have an evo 4 and just recently when am driving normal when revs reach 1800 rpm the car kind of coughs as if u take ure foot off accelator but when u go heavy on it it doesnt seem to do it also when idling and u gently press accelerator up 2 1800 rpm and hold it it starts hunting revs goiong up 2 1800 down to 1200 up and down up and down if u know what i mean but again press it heavily it doesnt do it any ideas thanks

 

[steveo]

I have a similar problem although my Evo doesnt feel like its "coughing". I get the rpms going from 900 - upto 1500 at different times and for no particular reason??? Mainly when im sat at traffic lights or roundabouts... My car goes in tomorrow for diagnosis, i'll let u know how i get on...

 

[ElDopesta]

You need to check your plugs and also check all your vacuum pipes. It may well be that you idle control valve is on it's way but we can get to that once you have made the advised checks.

Let me know how you get on.

El

 

[k13nay]

defo not the afm changed plugs and coils last week so defo not that i was thinking the idle control valve also noticed when its doing it the injectors are clicking if this helps

 

[John@SVA]

From what your describing it sounds like the idle control valve is going faulty.

they can be cleaned out with brake cleaner but doesnt always fix the problem.

if i can be anymore help drop me a pm

cheers
john