Hopefully someone can give me a hand. I have a 91 civic LX that I did an auto to manual and b18 swap to I stayed obd0 since I already had most of the parts car originally started ran a few moments and died due to code 3 (ckp) and 4 (map) after 3 ebay distributors with no luck I got one from autozone and it starts and runs but I still have the same codes and it will not go over 3500rpm. My exhaust does not have a spot for a O2 sensor and is currently only header downpipe could no 02 be causing the ckp issues? Thinking map is bad as car had no change when I disconnected it or is there another way for me to test it?

 

Did honda-tech die?

 

Are you clearing the codes between tests?

A bad map will cause the limp mode. With no map you can't compute density in the speed density system.

 

Yes the codes do not show until it is running either.
I am waiting on a new map now so hopefully not much longer there

 

I assume an obd0 b series harness was used?

 

No I modified my harness

 

Might start with reviewing your harness modification if the map sensor doesn't fix that code. Could also be you CKP error.

 

I have gone over my modifications and all seem good nothing loose or disconnected I'll see if I can find the info I used

 

CKP wiring needs to be shielded all the way back to the ECU and the shield needs to be grounded.

 

That could be my problem I wasn't aware they needed to be shielded and shield grounded I'll see what I can find for shielded wire. How do I ground the shield?

 

Shield is usually grounded to the sensor ground at the ECU side but my memory is a little fuzzy on the older stuff. I have an ETM I can look at later.

 

Would I be able to ground it at any ground point as long as it's solid and bare? Or does it need to go there? Thank you for your help

 

 

Found a quick pic on the internet. Looks like the shield gets grounded to G101, I believe that is the thermostat housing ground.

 

 

So if I swap the ecu pins to the shielded wire put those to the clips at dizzy and ground the shielding to the thermostat housing it should be golden?

 

Also I cut the shielded wire from an old all stock harness pulled from a previous scrap car and the shield was soldered to a wire that was ran to ground will that be alright here?

 

Perfect on the salvaged harness idea. That was probably a CKP harness.

 

Awesome thank you again for your help hopefully I can get it done today. I'll be sure to let you know

 

Got it changed over to shielded wire from dizzy to ecu and grounded at thermostat housing with no change haven't had a chance to change map as it started raining

 

Now the expensive option. Find a good OEM distributor.

 

I just spent almost 300 at AutoZone for this one where else should I go?

 

Is it a stock ECU? Ever had the capacitors replaced?

 

It is a stock pr4 ecu I've never had capacitors tested but a friend of a friend threw it into his ef bswap and it ran it fine with no codes

 

Borrow a known good distributor?