Alright. Here is the story. 96 EK hatch, 96 GSR swap. 97 GSR ECU. Engine has ITR pistons, flat faced valves, omni springs/retainers, header and an warm air intake. Wiring is from a 96 DX hatch, did the 3 to 2 pin crank position sensor conversion and IACV conversion. Added knock, IABS, and vtec. Car feels VERY slow up top, sounds muddy.... thus my issue begins.

So it sounds like Vtec isn't working. I went for a ride, unplugged the solenoid, made another pull. Felt exactly the same, sounded the same, etc. Vtec is clearly not working. NO CODES with the stock OBD2 P72. IABS work, etc. I can hear that changeover, but its obvious vtec isn't working. I traced the blue/black wire on the Vtec pressure switch and confirmed continuity to C15. Good connection. I traced the green/yellow on the solenoid and confirmed continuity to A8. Verified the black wire on the pressure switch has continuity to ground. Everything seems good, right? Removed the solenoid, screen is squeaky clean, don't see any problems, connected directly to 12volts, its working. At least it clicks, I can't SEE anything going on. So, I decided to try a P28 with a conversion harness. Chipped it up, made a brand new chip, etc... Code 21. Strange, I checked the conversion harness, connection is good for the pressure switch. Nothing is loose, seems fine. Tried another BIN and chip. Same thing. Got a P72 I had in the garage, tried that... same thing, code 21. At this point, I was pretty confused. I swapped Vtec solenoids. Tried that, same thing! Swapped it again with a third one, same thing, code 21 on all the OBD1 ECU's. Put in the stock OBD2 P72, works fine...that is to say, no codes. So I wired the Vtec solenoid to a toggle switch. Went for a ride, hit the switch around 6k, noticeable change in the top end power. The car actually pulls now, even the tone is different.. Pretty evident that it works.

So here is the issue in recap...

Vtec not working with stock OBD2 P72. Top end power SUCKS. Car ran 15.4 @ 91mph like this. NO CODES.
ANY OBD1 ECU I try throws immediate code 21. Vtec does NOT work with these ECU's. Tried several chips and ECU's. Same issue.

Anyone got any ideas?

 

strange, since OBD2 ECUs tend to be more picky about setting codes than OBD1 ECUs.
did you have the VTEC coolant check or speed check disabled with the chipped OBD1 ECU?
you may have a coolant sender or VSS issue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">strange, since OBD2 ECUs tend to be more picky about setting codes than OBD1 ECUs.
did you have the VTEC coolant check or speed check disabled with the chipped OBD1 ECU?
you may have a coolant sender or VSS issue.</TD></TR></TABLE>

The chipped OBD1 ECU's have nothing disabled other then the knock sensor for the P28. I want to solve the problem, not cover it up with disabling the sensors, you know? The speedometer works flawlessly, I don't think there is a speedo sensor issue. The car runs excellent otherwise. I've put about 60 miles on it with no issues other then it being retarded slow. I mean, its like a damn Civic DX could beat this thing up top.

 

disabling things may cover them up, but if things start working, it also tells you where the problem is...