JediKnight4life

I have just swaped in a D16Y8 head on my D15B7 block in my 93 del Sol S. It runs fine, except the idle surges between 1500 and 2000 rpm CONSTANTLY. My first check was the throttle body gasket since i didnt replace it. I replaced it and it did not fix the problem. Second check, Idle air control valve. I cleaned it out and put it back on, but that didnt work either. I unplugged the sensor to the IACV and fired it up, and it surges between 1500 and 1600 with a check engine light. Plugged it back in and it went back between 1500 and 2000. I took off the IACV and it surges between 1000 and 3000. I have no idea whats causing this and any help would be greatly appretiated. By the way this is my first post on honda-tech and it wont be my last!!!!!!!!! THANK YOU!!

slowpurplehatch

I had the same problem when i did my swap. check for a vaccuum leak especially around the intake manifold. if you have a different year manifold and head then they might not be matching up just right. I think the 99-00 ex manifolds are the ones that cause the problem. Also, you could try checking the throttle cable, make sure it isn't stuck in a partly opened position. mine while act up from time to time, just have to get it in the perfect spot. Hopes this helps.

JediKnight4life

I used my stock intake for the swap and i put a brand new intake manifold gasket on there when i had it off. As for the throttle cable, i thought loosening it might do something productive but it didnt. I will check for leaks around the intake manifold gasket tomorrow....is vaccuum leak a 100% cause of the problem??? or maybe a bad sensor or something??? Thanks again!

JediKnight4life

Alright, I fixed my problem last week and I figured I would answer my own question because nobody else did. On the back of my throttle body there was two 8mm bolts holding on a plate. On the front there's a hose for coolant to run throught the throttle body. Take off that plate and youll find a white, plastic screw thing. Mine was totally unscrewed and boucing around in there. Its spring loaded so to screw it back in, press down and turn it at the same time. Its like a reverse medicine bottle top. Tighten it down, put it back together and start it up! By the way, its way easier to work on it if you take the throttle body off. Thanks guys!