1720 vtec conversion
 

ok im kinda in a pickle here.hope some of u can help ok so i got hold of a p06 ecu i had a spare p28 so i decide to try to take all the vtec stuff out off the p28 and putting in in the po6.i seen where evrything was thanks to xenocron write up for the 1720 board.well i got everything soldered in the po6 and chipped it.ok it starts shows no soild cel untill vtec hits then a cel shows up(noone was smart enough to grab the code)so i get a call saying vtec doesnt hit and a cel sows up well i ask what cel and they tell me i dont know,well i thought damn that aint going to help0 me troubleshoot it.so now im wondering what i did wrong,one thing i did noitce is that the p28 has what looks like 2 vtec high side switches.i know the one that came out of IC14 was the vtec switch but what the other one for?resaon im asking is when i took both them out i sat them side by side and keep working on the board well i didnt really remeber which was which so i just grabbed the one closes to me and soldered it in the board.now my question is could that be why vtec didnt engage cause i put the wrong swtich in there?everything eles is in excatly how it should be for the 1720 board.its not showing a soild cel so it cant be nuttin too serious.im hopeing xenocron sees this and gives me his advice.btw the po6 and p28 were both 1720 boards!!

fyi the vtec p28 had a lifted pad and there was a burnt trancer so it was trash the po6 i had just siting around and i though i would give it a shot for the first,i never though it was going to be sold,i never got a chance to test it or anything.

Re: 1720 vtec conversion
 

Make sure you have a NPN in Q26 NOT an PNP.

Re: 1720 vtec conversion
 

oh i think your right cause i rember the part saying pnp.what about that high side switch are they 2 inside a stock p28?

Re: 1720 vtec conversion
 

The P28 sounds like it was a similar 1720 board. That older board had a few redundant circuilts, and the extra switch to the right (IC13) is the duplicate switch for VTEC. IC15 and IC16 are the main & duplicate trans lockup switches. Both ecu's should be fine with the 5050 style, so I doubt that's the issue.

Also, make sure you shorted J10 with a peice of wire. W/o it it will think no switches are installed.

Re: 1720 vtec conversion
 

yea j10 was jumped.what pisses me off is noone grabbed the code and that righ there will tell me whats wrong with it.im going to pick it back up tomroow and try to trubole shoot it.