i just finished doing a b20 vtec project and my car is doing some weird things.i have asked people about it and no one can give me an answer.the problem started after i put the head on the block i was running a stock b20 with the basic boltons and a p75 the i put the vtec head on and built it a little and running a stock p28 waiting to chip it and tune it. but when i got it i was told the IACV was bad so i replaced it and now when i am crusing the car slows down considerably and then jumps like i just floored it and it does that every 30 secounds or so while im driving,but if i feel it slowing down and i take my foot off the throttle or let of then get back on it it drives normal for about another 30 secounds unitl it does it again...what could it be

 

does it only happen when your already up to speed and your trying to stay the same speed?if so then my car does the exact same thing and i have no clue what it is.i hope someone can answer this question

 

What rod bearing clearance did you use? Compression ratio? Is this on Hondata, Crome, DTA, or Motec? Do you have a Skunk, AEBS, or Performer intake manifold? Which works best from your testing? Did you see a differance with changing fuel pressure?

 

it happens when im trying to stay at the same speed

 

found out that it might be the harness so il keep you guys posted