Long time H-T.com reader ,first time posting. I recently did a D16Z6 mini-me head on my D15B7 block and it didn't work out so good,bad throttle response and it had low idle,i don't know why, and so i decided to put my perfectly fine working D15 head back on. Now when i first started the car it started ,BUT, the RPM went straight to around 3800 to 4000! I've searched and troubleshooted with idle screws to cleaning my IACV, checking my vac lines, and nothing. so what could my problem be? I haven't driven my DD car in 2 weeks now and i just don't know what to do.

 

Vacuum leak somewhere.

 

Or you could have put one of the lines backwards. Does it keep on doing it once it is warm? I would get nice schematic and reconnect everything again

 

Screw that D series motor. If you have the stacks just drop in a b16

 

Have u also tried you idle control adjustment?

 

I would say h22 lol

 

i don't know, i don't keep it on that long it scares me lol. I do something that I've searched and troubleshoot and if it doesn't change idle I turn the car off.

 

no i dont have 'the stacks' lol but im trying to keep it just cause its a real good gas saver (1.5)

 

oh and exactly, how do i adjust the idle control?

 

adjust the throttle cable?
vacuum leak?
try adjusting your distributor if you dont have adjustable cam gears

 

That's a high idle I'm going to say intake gasket leak or leaking injector oring.

 

problem solved. wow. was missing a throttle body gasket. cant believe it made that much of a difference though, i mean...cold start jumping straight to 4000 rpm ? thanks for all the replies.