Hesitation when VTEC engages

[boofman11]

Have P28 with S300, JDM b18C wiseco 9:1 pistons, eagle rods, precision 5831e, log manifold, 2.5" dp and exhaust, tial f38 with 11lb spring connected to vacuum manifold direct, id1000s, M&W pro 10 with crane 92n coil gapped BKR8EIX at 0.27"

. Was running E85 and switched back to 91 and there is a pretty bad hesitation around 4500-5000rpms, sometimes it can make it to 5300rpms.

I tried moving the VTEC engagement point and it did not seem to affect this issue. I am aware its very rich when boosting and i keep lowering the fuel in those cells little by little, but seems like the issue has not changed.

Any help you could provide would be much appreciated.

[willie4x4]

iam having the same problem does yours only do it for a few seconds then rev fine

[boofman11]

I just let off gas when it happends. Seemed better when i had the 16psi spring in, now i have the 11psi spring. Its right when VTEC kicks in it just jumps in and out of VTEC hesistating.

[willie4x4]

Your tps doesn’t look like it is working

[boofman11]

I just checked that graph i see what you are saying, i think when the hesitation happens i let off the gas completely maybe. I just checked the range it seems smooth, wonder if it could be it getting warm though? weird

[boofman11]

Ill try a spare one i have, the one installed on there is aftermarket and unknown brand or age.

[boofman11]

Changed TPS out with another, verified calibration. Same hesitation. Bummer..

[Hondata]

Your air fuel is richer than 10:1 in places. That is the problem.

[boofman11]

Your air fuel is richer than 10:1 in places. That is the problem.

You were right, had to end up taking 17% out of all secondary fuelmap.