Codes 21,29,41,87 after mass air conversion

[fordman54935]

After completing the mass air conversion on my 88 GT I'm having trouble getting it to stay running when cold (and it runs so rich your eyes water), and is way way down on power, and will buck like mad after a hot start. I have a solid, steady 18" of vacuum at idle, the TPS is set at 0.99 V, timing at 12deg BTDC (spout out), and 39 psi fuel pressure at the rails. I pulled codes and got:

21: ECT out of self test range (pulled codes with engine at operating temp)
41: O2 sensor indicates lean on bank 1

Those two codes dont worry me too much, all of those parts should be replaced anyway (I'm sure they are all original)

29: Insufficient input from Vehicle speed sensor
87: Fuel pump relay primary circuit failure

The last 2 codes are what concerns me, since the mass air conversion required wire splices to the FP relay wiring and VSS wiring. When i did the swap all my connections were soldered/heat shrink insulated and I know my wiring is good and routed cleanly (already checked it like 3 times)

I plan to replace the 02 sensors and ECT, but does anyone have input on codes 29 and 87?

Thanks!

Edit: The cruise control works fine after the swap, and I have a fuel pressure guage permanantly mounted to the fuel rail and have yet to see anything odd with it (example - when removing the vaccum feed to the FPR, the FP rises a few psi to about 41-42 psi)

 

[Daggar]

Don't be so quick to swap out those sensors... particulalrly the 02 sensor. It may infact, be doing it's job. The EEC saying that the sensor is out of range and not switching doesn't necessarily indicate a bad sensor but instead, a poor tune (meaning your AFR isout of whack).


Your last two codes:

So you did hook up the wires for the fuel pump and the VSS sensor, is that correct? If so, then yeah... I'd trace them back down and see what the deal is with them. They will not however, effect the performance of your car, tune, or conversion in any way shape or form. So don't be too concerned about the codes until after you've got it all running correctly.