i have replaced every vacuum line and clean the iacv 3 times still surging idle and its getting worse with it getting colder out.
could it just be a back iacv we do have 91 crx si that i can pull parts off of at our shop that was bought to gut.

 

id try the crx iacv.

 

ya i figured that i will when i go to the shop in the morning but its getting damn cold out side to be pulling stuff off and we cant roll the crx in the shop as it dont roll anymore lol.

i am gona be gutting the crx for all the wiring we have a dohc zc i am gona be putting in my car when i get a chance.
all the brake stuff too and under dash wiring it seems that my car was a shell at some point and the put it back together in about a hour dont think its the original under dash harness there is no connectors for my rear defrost and wiring dont fit right

 

I would check to see if you have air in your cooling system and if thats whats causing your idle problems then bleed the air out of it.

 

 

well i am flushing the radiator also and changing the whole fan assembly out this one never worked but the car has never overheated either always stays low in the temp side. maybe that will fix it.

i did talk to a buddy a while ago about it he said maybe this piece on the back side of the carb was bad he delt with it before and that solved it for him. i was planing to bypass all of this and swap the zc in but i have been super busy and i am kinda loving the 30 mpg i get in town even driving with a slightly heavy foot

 

i replaced the throttle body and put a new gasket and it solved my idiling problem on my zc sohc...!!!

 

yea i have sprayed the crap out of it with carb cleaner so many time rpm never jumped or bogged i even tried it with the propane we have at the shop. took it off and checked it out once before too and it was perfect replaced the gasket too. its not really a huge problem for me but the last couple days it has been really annoying.

i have a lot i am doing to the car in the morning we will see how far i get defiantly have to get the radiator flushed and want to pull the dash and see if all the other plugs in are tucked some where i need rear defrost. then we will see if i can find the idle problem. then i can move on to gutting this crx if its not ***** cold out and i have time before we scrap it