What's up ht. I have a 92 civic with a b20vtec swapped. Motor ran great for the 3 years I've had it. Until recently. I did a pull with a friend and it acted up and cut out. Changed the whole ignition out from dizzy to plugs to wires. Found out that the thermostat ground was causing the problem with my tach and the car randomly dying. Now it runs great again until I hit 6000 rpm. It acts like it goes into limp mode (won't pass 3500 rpm) unless I reset the ignition or it drops under like 1500 rpm. Its not throwing any codes before or after limp mode. I've tried 2 ECU's now (original was a p28 that came with the car with a locash racing chip and now a p28 with hondata s300 v2)
I don't know where to go from here.

I have tried to google the issue and end up with no answer.

 

Does VTEC still activate?

 

Either the ecu thinks the engine is still cold (look at the S300's datalog for EVERY sensor) or your tach sucks. Verify the tach is not off by using the S300 datalog.

 

VTEC does still engage and hondata is reading the correct engine temps. As far as the tach goes, I know the one in my car is off. The 6000 rpm comes from the hondata readings.

 

Bumping my old thread to hopefully help anyone else out that may have similar issues. After many years of chasing this problem down, it ended up being the AutoZone distributer. Something with the sensors inside was causing the car to fall flat on its face. Once I replaced it with an OEM dizzy, all problems stopped and the car ran perfect again.