yah so i just recently swaped a b20 into my DC1 and im have idling problems.. it ldles from 2k rpm and drops to 1.5 then goes back up to 2.0 over and over and over and somtimes even idles a little higer than 2k. we have checked all the valves and there is no air leak. we have basicly checked all the obvious reasons.. and now im left with no conclusion.. any 1 here have any anwsers or tips that could help me?

 

Have you had it tuned if so then what kind of ecu are you running on p28 or p72? If you never got it tuned then that will help it alot. I have a b20 vtec and mine did the same thing.

 

its a stock 1990 ls ecu and as far as tuning my buddy tried adjusting the throtle screw and did nothing

 

ok i see but what im thinking of b20 vtec you have the complete b20 right. here are other things you can check there are alot of reasons for hi lo idling. get some intake cleaner and spray around where the intake manifold bolts up to the head. if it revs up then you have a bad gasket. also check spark plugs, wires, cap, rotor, also check your head gasket. usually another thing you can do is tighten your throttle cable a little. check your idle air control alot of people use a coke can and wrap it around. just check all that stuff and let me know what things look like.

 

coke can?? how does that work out???

 

yah a jdm b20b non V. with a b18a tranny. ill check those few things. thanks a ton. ill keep in touch and let u know how it went.

 

you need an ecu that has a base map of a 2.0 liter....running a 1.8 liter ecu on a 2.0 ecu is pretty bad

 

he said b18 tranny if he has the b20 motor non vtec it should have come with the correct ecu.

 

also I forgot to mention your fuel system check everything you should change the fuel filter. one thing you can try which i never tried is the fuel system flush cleaner ****. I don't know the results cause i never had to add it. or you can take it to honda and get the real fuel system cleaner but don't go and do that checkk all the other things first. you can pay around 80-100 bucks and get it tuned I don't mean ajusting a throttle screw they get into your computer and ajust everything like air fuel ratios and fuel maps it helps a if you don't have the money for fork up just drive it this occurs alot in honda motors its not really a big deal just annoying *** hell!!!!

 

he said its a stock 1990 ls ecu.........