[paleocaionut]

Hi,
I have an EVO 4 with the following mods:
Evo 4 ecu
Evo 5 engine
Evo 5 injectors
Evo 4 turbo
HKS intercooler and hardpipe kit
The problem I have is that the car is hesitating and bucking between 1200 and 1800 rpm, it can be felt especially in gear, if you drive along at 1000 rpm and try to accelerate the car is just bucking untill you you push in the pedal and let it rev to say 2000 rpm, from there on it's working just fine.
I can also feel that the engine is missing when at a stanstill between 1200 and 1800 , but once and again I can feel it missing slightly even at idle (900 rpm).
I have disconected every vacuum hose, checked for vacuum leaks with engine starter, disconected the BOV and the IACV, changed the plugs, can't seem to find the problem.
Could it be the injectors (560cc compared to stock evo4 injectors 510cc) ?
What else should I check?
P.S.: the idle hunts up and down untill the engine reaches 70 degrees C.

 

[madhillbilly17]

yeah i would have thought it could be your problem as the 5 ecu will be mapped for different injectors,so your a/f ratio's will be wrong,warm up enrichment's and so on,i would buy some injectors anyway and go from there you need them anyway :smthumbup