If you've been following some of my prior threads, you know I'm having trouble with AFRs. My 1985 vette, with 1985 ECM all stock except for a beefed up motor running AFR180 heads with a 1987 cam, has AFR numbers of 16.6:1 average. During modrate acceleration it bumps down to 13:1 - 14:1, then back up to 16.6:1 average during closed loop idle and cruise.
I just remembered that awhile back I needed another 1985 "calpak". In 1985, "calpak" is not the ePROM but rather a chip that sits next to the ePROM. As I remember, it has calibrations hard coded into it.
Well, at the time, GM no longer sold these chips so I defaulted to using one I got from a 1985 Camaro at the local wrecking yard. I installed it and it just occured to me that this could be what is throwing things off.
All things considered; all is new or near new. MAF, injectors etc.
As far as I know the 870 ECM was the same for Camaro and Corvette, the only thing that seperated them was the PROM. The "cal" chip just has basic info, mostly used for "limp home mode". but does have thngs like number of cylinders, injection type, etc.
Corvette Store
Maybe? - My problems are....
