Hi. I have a b20b 91 civic sedan. It is converted to OBD1 running a P75 ecu and OBD1 distributor.

Symptoms:

-The car loses power religiously after 4400 RPM. It sounds like it is running on 3.5 cylinders... Its like having a reverse VTEC.
-It seems to idle like it has a small vacuum leek.

Attempted solutions:

-Replaced the cap and rotor.
-I've tried two different junk yard TPS's. Both seems to go from 4.5V to .45 volts without dead spots and I calibrated them perfectly.
-Replaced spark plugs. 44 thou gap.
-Adjusted timing on the distributor.
-Checked map sensor outputs. I am getting 5V between green/ yellow and yellow/ground, and 4.66V with yellow/green. It seems to check out.



I only have one code; it's the No. 1 CPS (code 9). I bought the car with this code and it's been running fine up until this point.

Could this be MAP related? What should I replace next? It seems to cut power right at 4400 RPM. It could be an ignition problem or something wiring related causing it to go into limp mode maybe? I did hard wire the OBD1 harness into the car but I was pretty careful not to mess anything up. That solved my o2 heater code... Anyways, please help me. I am stumped on this one. Thanks

-Justin

 

id do a compression check first
does the car smoke?
also have your cat checked could be plugged up.
if your map tps was bad ud throw codes for them

 

well just because you had the code before and it ran fine doesnt mean you can ignore it, fix the code first. its either the dist, the wiring or ecu.

 

Figured it out. The wire on yellow/green (OBD1) white(OBD0) wire on my distributor harness was breaking at the harness on the distibutor. Re-ran grounded distributor wires right to the distibutor from the ecu. Problem solved and no more code 9!

This simple fix after replacing fuel filter, distibutor cap & rotor, Distibutor, Ignition module, Coil, Wires, different fuel injectors, Fuel pump sock, Map sensor, Throttle position sensor, o2 sensor... I dont even want to list the rest...

Thanks,

-Justin