okay the other day i was driving my car and noticed it was gettin a lil small bog to it but would clear up after 3 grang rpms....now it boggs really bad and starts to clear at 4.5grand and still has a few puts in in as i am gettin on it to see if it will clear up....its a good motor i just got it it ran great for 4 months, its a d15b1 with z6 head so can any one please help me

 

any CEL's? what did you do to it right before that started happening? how do your plugs/cap/rotor look?

 

i had the same problem. and same motor.

what ECU are you running?

the normal D15b ecu? P08?
or a P28?

when i ran the p08 (1.5)on my 1.6 ZC. it had the same problem. until i changed my ECU to a 1.6 and ran it with the P28 and my problem cleared.

now i am running the P72 on mines. it still works fine

when you did your vtec head, what timing belt did you use?

that also can bring off a tooth.

but from what i have diagnosed, it was the ECU that threw off the motor by .1 liters.

 

true but he said that it ran fine for 4 months, so he could either have the wrong timing belt and it jumped a tooth or soemting went bad

 

can it also be the fuel pump??

 

cap and rotor for sure! had the same problem on mine, popped the cap off and it was so corroded i was surprisd it even ran. popped a new cap and rotor in there and it was good as new