Hey everyone. Before I go on with my question I'm just gonna let you all know that I've already tried the search on this forum and several others and haven't found anything that's fixed my problem yet. I joined honda-tech because I think that the information given here is the best and most useful of any other forum. It's going to be a long post as I'm going to be as detailed as possible about what's going on.

Now for the problem I'm having. I recently bought a 93 honda civic hatch with a 1994 B18c1 swap(this isn't my first honda or my first vtec application) my problem started with the car not runnin properly when I bought it. I knew hat the problem was and. Got a good deal on it so I went through with the purchase. The guy I bought the car from had the wrong harness plugged into the map sensor. I plugged in the right harness and the car runs great except for having no vtec crossover. After a lot of time and effort and trouble shooting I found out that when the swap was done he used the wiring harness that was already I the car(single cam non vtec). I'm not too good with wiring so my friend helped me wire it in. As it turns out that wasn't the only issue. The ecu was a p06(single cam non vtec). We found that out by plugging in my friends p72 ecu I and I got vtec crossover twice but after I shifted the cel would come on and vtec wouldn't crossover. I ordered an obd1 chipped vtec ecu from phearable.net with a custom basemap. I got it in the mail today and when I plugged it in its giving me code21( vtec solenoid). The things that we've tried so far with the wiring were to wire it directly. We tried a skywire. We've tried secondary bypassing. Everything we could find from other forums. The solenoid works. We plugged in a power probe and its clicking and I cleaned it out really well and there's no clogs or anything. I know the ecu works because I plugge it into my friends car and everything worked fine. I just don't know what else to try so I was hoping someone here would be able to give me a few more suggestions. I tried to be as detailed as possible. If there are anymore questions about my setup or any problems Ive had ill be able to answer them. Thanks.

 

If the ECU works in your friends car, have you tried comparing your friends cars wiring and try wiring it exactly the same in your car, if that's possible? I'm pretty sure that solenoid only requires a power and ground, so as long as you are getting your good power from your ECU, and a good ground it should work. Make sure all grounds are solid, that could be the source of your problem, even running a ground wire straight from the block or chassis to the solenoid to make extra sure you have a good ground. Also you can make sure your oil pressure sensor is wired correctly from your ECU, and make sure you have a good oil pressure sensor.

 

Actually when you mention the grounds there was only one ground on the car when I bought it. I added another one and plan on adding at least two more to make sure it's all good. As far as the wiring goes my car is wired the same way as my friends. He had the same problem with his car and fixed it with the skywire. I might not have too much time tomorrow to add some grounds because of thanksgiving and having to spend time with my family but ill get to it as soon as possible.

 

https://honda-tech.com/forums/hybrid-engine-swaps-18/%5Bfaq%5D-%22my-vtec-doesnt-work%22-1812135/