Idle issues

So idek how to ask or say this…I have a 1998 civic lx stock d16y7 motor me an my friend have done multiple motor swaps only b series motors though we’ll I swapped it with the d16z6 vtec ran fine in my friends car I looked everything up to make sure I was doing it right… When I put it in now it runs wierd if I try and hold the gas in neutrAl… At 15-1700 it does like a launch control how it revs up and down real quick I cleaned the iacv and the tps is good and ideas? I read it could be a bubble in the coolant or the nipple in the distributor might have broke or something please help I just had a baby and this is not safe for him

I’m not the grammer police so I don’t care if you capitalize correctly or use the proper punctuation. I not even very particular about spelling, but you need to write clearly enough to be understood. I can’t help you because I can’t figure out what you are trying to say.

Please review and rewrite your post.

??? I agree with @keith.

Let me make an attempt. If you have the car in neutral and rev it, at about 1500-1700 rpms it goes nutty and starts revving up and down. Is that what you were trying to say? If so then maybe you could also say what it does the rest of the time. Like when it’s actually at idle. Or when it’s in gear or when you try to drive it. And stuff.

What year was the donor engine from and which set of electronics (computer and all of that) are your using? The '98 car or whatever was with the donor engine?


Your car originally had a non-VTEC engine, correct?

And now you’ve got a VTEC engine under the hood, correct?

Did you use the VTEC engine control module from the donor car?

Is your car a stick shift or auto?

Was the donor car a stick shift or auto?