I am having issues with the vtec crossover on my turbo B18c. I am not getting any CEL's. The car pulls great until vtec engages, then it boggs and sounds like its hitting a rev limiter. When I unplug the vtec solenoid the car pulls all the way to redline with out hesitation. A/F are in the 11's even when Vtec is breaking up. The rev limiter is at 9500 on crome. Here are the things I have tried and changed out.

Changed
ECU
Chip
jumper harness
Basemap
distributor
plugs and plug wires
7 heat range plugs .025 gap
crossover point, 5k-6k same thing
Cleaned vtec solenoid screen
changed solenoid and pressure switch
Tested soleniod, clicks with power ran to it
compression test 180 across
Pulled oil pan, no dents, pick up screen was also clean
Pulled cam caps, O ring and dowels are in place
Hooked up oil pressure gauge inline with oil feed for turbo, 75 psi at WOT
changed oil and filter
Checked timing, which was good
adjusted valves


I have done everything I can think of. My tuner says he can't tune the hesitation out and he has never came across an issue like the one I am having. Any help would be appreciated.



Thanks

 

I will try to get a scan of the fuel and iginition maps if it helps. I have tried everything. I have owned the head for the last 5 years and Vtec all ways worked all motor, the block was in a friends car and he had 0 issues. I was thinking about going from skunk2 stg 1's to stock GSR's just to see if it would change anything. I know its a long shot, but I have to try some thing else. Any ideas?

 

Log manifold? What manifold? Skunk2 stg 1s?

 

11's seems a bit too rich.. i remember my friend's turbo gsr popping at 12.2-4, at 12.5 was the richest we could go with the plugs gapped to about .032-0.34

i really think 11's is wayy to rich

 

it will pull through afr in the 11's no problem. post the maps.

 

switch to smaller cams or set vtec 6500+ rpm
what manifold?

 

I am running an inline pro log manifold with skunk2 stage 1 all motor cams and precision sc34 turbo. I am goinng to swap in my gsr cams today. I will try to get the maps up, if the cam swap fails. Thanks for the replies.

 

ive this problem on several cars i tuned. the combination of a large cam and log manifold/restrictive exhaust will cuase break up at VTEC crossover. either go w/ a smaller cam or change exhuast/manifold. one car i was tuning had an inline pro manifold and some unknown cams which created alot of breakups. we swapped in a set of GSR cams and car pulled through clean

 

Problem solved with stock cams. I never thought of stage 1's as a large cam. This problem should be on the FAQ.