Heres the story. I have a 92 Hatch DX. Before i did the engine swap, sometimes, mostly on a hot day, i start the car, it idle then it stall out. I figure I just hold off until i can get my engine swap. So, now i have my new engine in. Its a OBD1 B18b1. Now the idle fluctuates, even when I have adjusted it. And on hot days, it always stalls out. When I turn the car on it idles high for about 5 secs, this is from stop and go traffic, then drops a good 400 rpms. The stalling part is what is confusing me the most. It is exactly what the car was doing when I had my Stock DX engine in. I have replaced, spark plugs, wires, distributor car and rotor, O2 sensor, Fuel Filter, Fuel Pump, ran some fuel system cleaning in for the hell of it. I would like to know everyones opinion on the situation here. Could it be a coolent system problem that is causing the stalls? More sensors? BTW, fuel pressure never drops, and there are no codes throwing. Any ideas?

 

Have you tried swapping the ecu?

 

I have pretty much the same problem I replaced the ecu and the whole engine the only thing that is making me wonder is the evap canister that stayed and has sensor or valve on it if I am correct and if that is stuck or broke then could it cause the car to do this?? Please help I can drive but the idle fluctuates too much. Thanks

 

Has this problem occurs after you finished up with the swap? When I had my supercharged b16a2 swap on....I blew a headgasket...and maybe piston rings..and I had that same problem. It would stall on me if I take my foot off the gas pedal. Check your compression. Your Map sensor...and Idler control vavle.
If you have or know someone who can lend you the parts just to test it...do that first. Good luck

 

well, i never had the stall problem, but when i got my b16a in, it had a serious idle problem.. it would surge from about 600 rpm to like 1500.. not a shop in the area could figure it out, but for some reason when i put my V-AFC in, the idle problem went away? but im not one to complain, so who knows..give that a shot?

 

i had the same problem, turned out to be a bad intake manifold gasket.