Hondata

Hi, i have a civic ek with a H22A7 engine and turbo charged. Running this on a P28 ecu with Hondata S300 V3. My problem is it cuts the rev limiter in at the vtec engagement point. If i disable vtec it runs perfectly, revs all the way to 7800rpm. But it i enable vtec, it revs to 5500rpm and then hits a limiter, the rev gauge reads 0 and it just goes along about 2000rpm. I have read this happens when the rev limiter kicks in, but what is making it kick in? I have lowered all the vtec requirements, like speed and engine temp and it still does it. Any help is highly appreciated.
Also if i rev slowly passed 5500rpm and then floor it it works fine. It only cuts out if i try and accelerate hard through the Vtec engagement point.
Thanks, Jason

IT sounds like you have a grounding problem and the ECU is grounding through the VTEC solenoid. Check all your engine bay grounds.

I will check tomorrow. But the vtec was working fine when I had the original ecu plugged in. Nothing has changed except for the ecu change. Could this still point to a grounding problem? Thanks again. Jason.

Based on your description it is most likely grounds.

Ok will have a look and let you know what I find. Thanks. Jason.

Ok. What sort of grounds should I have? I have the battery which has two earths from it. One to chassis and one to a point on the strut tower where another one bolts to it and runs down to the engine. Should there be anymore? Thanks. Jason.

Is the vss working?

I have checked all earths and all are good. Even added some more in to try it and it's still doing it. VSS is fine.

here is the datalog file if that helps

Post current calibration as well

here is the calibration, its based off a calibration from this forum

anyone able to find anything wrong? thanks, Jason

Anyone?

Have you tried the ECU in a known working vehicle?

This is a known working vehicle. It worked fine on the original ecu.