alright, i have an 88 hatchback that has had a b16 in it for about 2 months now and it runs great except once it gets warmed up. When it's cold it runs smooth as it could, great throttle response and stuff. But once the car gets to normal operating temperature it hesitates all the way up until about 3500rpms then it goes fine. or atleast it was for the last few months, now all of the sudden it hesitates top end also, it'll start to pull then cut then pull, its misfiring not terribly but enough to hurt performance. I have a new cap, rotor, plugs, timing it perfect both cam and distributor, grounds are good and all there. I'm running a zdyne single wire vtec Si ecu and it's not throwing any codes or anything. I'm getting really annoyed now that it happens all the way through the rpms and CMI is this weekend and i planned on running but iffy now. Any ideas???

 

Check the spark plug wires....Pull each one out at a time and see if the car starts to hesitate and die..If so could be your rings..Or you can check the oil thats common....

 

Switch your O2 sensors. I had the same exact problem and my sensors were backwards. I changed them and it runs perfectly now.

 

i'll try the switcharoo on the o2 sensors,
i'll try that first, then the plug wires.


i'm not sure why you would think it's my rings though.

 

only when it gets warm huh? sounds like it could be an ignitor to me.

 

what do the plugs look like?

 

it's been doing it since i got the motor, then about a week ago the ignitor went out all the way and wouldn't spark anymore, then i put another ignitor in and it's the same story and top end as well.

plugs are brand new and look fine as did the old ones.

 

same story with me , i jus got a new motor for my 97accord nonvtec, and at first it was stuttering and misfiring, now i get no spark. i dont know what the **** to do next

 

change your ignitor, that's what i had to do when mine went out, then i just put some new plug wires in two days ago and the problem is solved. amazing how simple it can be.

 

u change the ignitor and now its all good?
did it crank all the time with no spark?