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?

 

maybe your knock sensor is bad.....
i heard somewhere before that if your knock sensor goes bad or something like that.... that it will like retard your timing and lean out your motor..
this same problem happened to my friend who drives a b16 crx and it was his knock sensor

 

i think that my friend had the same problem....he would be driving then out of nowhere the car would bog....if you are experiencing the same thing the injectors are probably bad and need replaced...thats what i did to his car.....you may have the same problem i would check that out...keep me updated on what you do.

 

With the problems that you are having, and if they are completely fine after unplugging your 02 -I would start off with trying fuel injectors.
Do you have a guage so that you can see what presure you are at?
Do you have a adjustable regulator that you may off adjusted incorrectly?

 

this migth sound dumb but check your idle control motors. the one on the back of the manifold and the one under neath the throttle body.. if u take a part the one under neath the throttle body ther is a big round plug that is kind of shaped like a bolt it sometimes becomes lose and cause this ploblem if it is lose just tighen it and its ok

 

Remember, the problem does not occur when running in open loop. I do not have an adjustable fuel pressure regulator and the injectors were just switched to gsr injectors for the obd-I wiring non-resistor setup. I experienced the problem with both sets of injectors so I do not think that is the problem. I was reading in H22A hesitation forums(much different motor) that knock sensor could give a bad reading. Where is the knock sensor located? Can I purchase a voltimeter and test it?

 

your knock sensor is located right above your oil filter.... or is right around there

 

Well, I also have an '00 head on it that is stage 2 ported and polished. My vehicle is also, in open loop, idling at 1500 rpms after popping vtec, and it idles around that point for a good 5-10 minutes afterwards. This is seriously messing up my ability to do quick shifts. I have a skunk2 manifold installed with hybrid intake system. Am I dumping too much air and not enough fuel? Do I need possibly new injectors or bigger injectors? I am really stumped here. I just want my car to accelerate the same way all the time

 

I had the same problem. It was injectors.

 

I don't even think my KS is connected. I have running a p30 ecu, is that maybe the problem? Anyways, I have not tried new injectors ever. So I would like to do that. Where can I purchase "GSR OBD-I" injectors? All I hear is GSR INJECTORS, no one ever says what year or model engine. I want to make sure I purchase the correct injectors from Acura and see if that fixes the problem.

 

your local auto parts store should have them and you tell them 94,95 or whatever gsr injectors