Ok guys, here it goes....I will paypal $25 dollars to anyone that can figure this one out...

I have B16a swapped into 1990 Crx Si. I had OBD-0 wiring with PW0 ecu and experienced this same problem. I upgraded recently to OBD-I to try to fix the problem but it didn't work.

The problem is that the vehicle is hesitating at quarter or half throttle intermittenly during driving. Usually when vehicle is driving for first 5-10 minutes you do not experience the problem, but after that is usually kicks in. The engine bogs back as if the fuel is being leaned. When I unplug my oxygen sensor(now 4-wire) I get a check engine light and the vehicle runs in open loop but I never experience the problem. When I had the old wiring and computer, I left the oxygen sensor unplugged as well to eliminate this problem. The check engine light never comes on when the oxygen sensor is plugged in and I am experiencing this problem. The 02 sensor has been replaced.
Why must my vehicle run in open loop consuming all this unneccesary fuel to run properly?

 

man, my old gsr ef hatch did that for a while too, but my problem was that i had my o2 sensors wired wrong(obd0) Also are you using a firewall map sensor or a throttlebody map sensor. For some reason my car ran a lot better with a throttlebody mounted map sensor then the stock one for the ef that mounts on the firewall.

 

I am using firewall map sensor. I have OBD-I now, should I still get the throttle body map? Where does it install and where could I get it? Did it completely eliminate the problem?

 

The obd0 map sensor is located on the firewall but if you can find a 0bd1 b16 or obd2 b16 throttlebody that map is located on the throttlebody. I went from a 1st gen b16 to a obd1 gsr and when i switched maps, it changed the idle and hesitation from night and day.

 

Im having the identical problem with my SiR2 in my 97 Civic. I changed out my Distributor cap and it doesnt even do it as bad. Let me know if you figure any thing out as I would like to fix mine to.

 

Well from other replies in another thread I created I have concluded that it could possibly be the injectors. When the 02 sensor is unplugged and the car is running in open loop the injector pulses stay wide open all the time thus the reason for burning more fuel. With the 02 sensor plugged in, it closes those pulses to conserve fuel but if they are sticking it would throw the timing off causing the bogging. So fuel injectors are definately a possibility here. But, any more suggestions would help.

 

Could be a bad fuel pressure regulator.