Just swapped a B18A1 into a friends 89 civic. Had a ZC in there before. The CEL is hard coding. Im not sure which one but my question is when the CEL is on is the ECU in "limp mode"? We think its the coolant temp sensor that has the wires crossed but not sure yet. Also the idle fluctuates alot. Goes from about 800 to 1500 and just keeps see sawing.

What would cause the idle fluctuation?
Would it go into "limp mode"?
Does "limp mode" affect performance?

Also if anyone has a diagram for the vacuum lines i would appreciate it. Some arent hooked up. Thanks guys.

 

the idle prob might be a bad throttle position sensor... my friends teg did that... gets really friggin annoying every time to push in the clutch to stop...

his idled from 800-2500 though... kinda funny actually =P

 

I had my idle fluctuate in my B18a and I changed the o2 sensor and it fixed it. As for the cel I am not positive here but which computer are you using? Did you switch wiring harness or just made the old one work? Can you get the code that the cel is spitting out?

 

Mine fluctuated in my GSR and I changed the TB gasket and it fixed it, same for a friend with a CRVTEC

 

check your codes, my rex did the same thing, I took a long screw driver and put it on my injectors(listen for a rapid clicking sound) my #4 Cyl was dead, a break in the wire somewhere so i spliced in to the injectors neg. side and ran it straight to the pin it said on the ecu and wa-la its worked and myy car screams!!!

 

obd 0 does not have limp mode the ilde surge is probably your idle air control valve (iacv) 2 8 mm bolts on back of mani below t/b theres a brass button with a white plastic gromet tighten an it should go away:rockon: