Right so here goes, i have been through numerous threads on this and other forums but cannot find any answers to my problem.

So i have a 1996 jdm del sol which originally had a d16 in it, swapped the engine out of my old 1994 uk del sol which is a b16a2. So obd2a to obd1 i believe. Once i got the engine in with the adapter harness for the ecu etc, i couldnt get vtec. Searched the net an found the a4 to d6 link wire mod which worked fine. I am now 4-5 months down the line and my car throws up cel 21 which i know is a different code but when i disconnect the link wire i can now get vtec, 1,2,3 gears are fine and then u change into 4th and it will stay in vtec for around 500rpm then it goes. Turn the car off put the link wire back in start it and then turn it off an take the link wire out and it will work again. But only through 1st 2nd and 3rd again vtec goes around 500rpms into vtec in 4th. I have checked continuity between the solenoid and numerous other wires running back through the loom and all seems fine, i know everyone suggests oil pressure but i have been driving it for weeks and weeks like this now and its still fine and i have always service it myself with the correct weight oil etc and it has enough oil. Any help will be much appreciated

 

Cmon 180 views but no replies!! Someone must have an idea??

 

You might get more replies if your diagnostic procedures were more comprehensible.
Clean/replace the screen on the vtec solenoid, make sure your oil pressure is good, and check your grounds. I would also run the wiring directly from the ECU. I hate those jumper harnesses.

 

Screen dirty on the vtec solenoid? What are you using to confirm in/out of vtec? What are you referring to as "link" wire?

 

To fix cel 22 there is a mod your do to link a4 (vtec solenoid) and d6 (vtec pressure switch) have taken the solenoid off and its clean as a whistle, and im pretty sure its not oil pressure have done over 800 miles with it like this surely it would of gone bang by now?? Could it be a faulty pressure switch?? I only say this as with the link wire in maybe it this the solenoid is faulty which is why i think it could be throwing cel21?? Have tested the pressure switch an it had continuity and one of the troubleshooters on here says if theres continuity its should b working.