I have an OBD1 converted D16Y8 in my 89 Si (using a stock P28 ecu, Z6 dist, injectors, int. manifold and boomslang OBD0-OBD1 conversion harness) It also has an underdrive pulley and adjustable timing gear which is set at zero. The P28 is throwing a check engine light at high rpm usually in high gear(sometimes anywhere between 6-7 grand in any gear). Also, when the car is brought to an idle, itll fluctuate anywhere from 700 to 1500 rpm consistently. The code that flashes is a code 22(2 long, 2 short) for the VTEC solenoid. I recently replaced the solenoid, and when testing to see if it fixed it, the code popped back up at about the same time that it did before I replaced the solenoid. The varying idle stayed as well.

I know that the varying idle could be a by-product of the underdrive pulley, but it doesnt seem to occur until the code flashes. If anyone has an idea or knows whats causing it from what Ive mentioned, your help would be greatly appreciated. Thank you

 

check the wiring harness for any loose connectors.

you must have run an extra wire/extra wires for the vtec solenoid/oil pressure sensor, so check those too.

that is really the only thing that could go wrong, if you have replaced the solenoid.

 

try swapping with a good ecu...i had the same problem with my obd0 b16 and pr3. it would drive fine under under 4800 rpm but once i passed that, the check engine light would come on for vtec solenoid...i tried like 5 different solenoids but they didnt work...when i changed to obd1 with a p30 ecu, everything worked fine...just a thought though...

 

code 22 is vtec oil pressure not solenoid im getting code 21 which is vtes spool solenoid

 

if u want to say goodbye to that code forever, splice the vtec pressure wire into the vtec solenoid wire. thats how mine is since i do not even have the pressure switch.
im using a 00 b16b solenoid which didnt come with it.

 

where did u splice it at? did u splice it near the solenoid or near the ecu...cuz ive heard that you can splice it at the ecu and ground the other end...or can u splice it at the solenoid and dont ground it....

 

I have a similar problem i have a b20b block w/ a b16 head and vtec is not kicking on. Im runing a chipped p28 ecu w/(uberdata) and a stock 94 integra ls wiring harness. I ran the vtec solenoid wire to pin A4 on ecu and oid pressure to pin D6. im using 5w30 oil (i heard that some ppl run 10w30 cuz the extra vtec oil line looses oil pressure) That is the setup and this is the problem. When i start my car it doesnt throw and codes so i warm it up and take it to 5000rpm and no vtec then when i let off it throws a code 21. The first vtec solenoid i had the check engine light was on right when i started the car and this one it just goes on after i let off around 4-5