Efi conversion has a stumble once warm, got codes

[rjrobin2002]

I had this Complete rjm harness and mustang computer on another motor that ran great when removed and installed it on mine. I have a stumble once on gear with the engine warm and on initial acceleration that seems to get better with more rpm.
KOEO codes 67 81, 82, 85, 84. What y'all got? No codes with KOER.

 

[xcntrk]

KOEO 81, 82, 85, 85 are all expected emissions codes from not having an EGR, Charcoal filter, and recirc solenoids. But 67 is interesting, apparently related to neutral safety switch. Are you sure it's plugged in and working (assuming you're using an AT EEC)?

67 - Neutral Pressure Switch (NPS) circuit failure
67 - Neutral Drive Switch (NDS) circuit failure

 

[rjrobin2002]

Where would it plug in, I am running it with a c4 which is what it was running with last time with no issues? Would it cause my stumble when warm?

 

[Viperwolf1]

Code 67 is common when there's a burnt signal return trace on the computer board. I would expect to see some other codes though. What computer code is it?

 

[rjrobin2002]

A9P, like I said, this harness, distributor, most sensors, and computer was just pulled off another bronco with a c4 running fine. I am still not sure I don't have some random vacuume leak or ignition issue.

 

[rjrobin2002]

And initial key on produced 40psi fuel pressure and held for a long time, so no fuel pump or injector issue unless it is creating some issue once warm and my pressure is dropping.
Should most of these engines throw some KOER codes? I think I did that right.

 

[Viperwolf1]

And initial key on produced 40psi fuel pressure and held for a long time, so no fuel pump or injector issue unless it is creating some issue once warm and my pressure is dropping.
Should most of these engines throw some KOER codes? I think I did that right.

You should be seeing some KOER codes. Not seeing them is another indication that the signal return is bad. You should open up the ECM and look for a burnt trace and might as well look for bad capacitors too.

 

[rjrobin2002]

Whats the correct process for retrieving KOER codes . I have only ever done KOEO codes.

 

[rjrobin2002]

Anything that I could of done that possibly caused the burnt trace if that's the issue? What all grounds should I have for Efi?

 

[Viperwolf1]

Whats the correct process for retrieving KOER codes . I have only ever done KOEO codes.

Same as KOEO, just start the engine after grounding the STI wire.

Anything that I could of done that possibly caused the burnt trace if that's the issue? What all grounds should I have for Efi?

Usually this is only a problem with the manual computers and a wrongly configured pin 30 wire. I have seen and fixed an A9P with this problem though. Hard to say what may have caused it.

ECM harness pins 20, 40 and 60 need to be grounded.