I've got an '88 crx with a dohc zc swap. Problem is, after driving the car for a bit, the engine idles with a quick surge and then drops and continues up and down. I've been told that I might need to bleed the radiator fluid. Could this be the most likely cause or what else might it be?
Any help would be greatly appreciated.
Thanks

 

could also be a vacuum leak .. might aswell bleed the coolant .

 

I had the same problem on my 91 hacth with a dohc swap and it turn out to be th eidle screw on the throtle body it was loose and the vibration from the motor made it turn in and out so i put a bit of liquid teflon on the screw and put it back on the thotle body and adjusted the idle and i nevewr had the problem again.

 

I had also been told that it might be a vacuum leak or the EACV. I guess I should start with bleeding the coolant and see how that works out.

 

Had a similar problem, turned out to be the ECU...

 

IVAC Or FCCV