Hi,im new to this site.i swapped my 1990 ZC crx engine for a D16A9 engine.
Told it should be a straight hassle free swap. The car is ticking over very uneven,
misfiring when revved,with a lot of black smoke.the l.e.d. in the passenger footwell
read fault seven.throttle position sensor which has been reset and hasnt returned.
we swapped the throttle angle sensor for a vtech one but it didnt make any difference
to the running. The ecu shows no fault now, but yet it is running very rich, drinking petrol,
black smoke, misfiring when revved even at 2500rpm. What can the fault be if it doesnt show
up on the ecu?

 

im thinking you might need a new distributor. that is the only thing i could think of, as the black smoke is generally a sign of unburned fuel. and since the DOHC ZC and the D16a9 are the same engine, they should work equally the same.

 

what ECU do you have? the ECU for the A9 does not read O2 sensor - the A9 reads CO2