SW Chip issue in my 86 911

[Marined]

I bought a SW chip from Pelican and when I got everything apart, the pins don't line up. The SW is smaller than my factory chip.

What should I do?

Thanks for your help,

Ed

[Tinkerer]

You got the wrong pin chip, they will give you a replacement as long as it isn’t a custom map

[Quicksilver]

Early DMEs had a 24 pin ROM chip and a fixed program. The later 28 pin ROMs had an upgraded program along with the data maps on the chip. Your DME is either a later unit or is an early unit that has been updated. I'm guessing it was updated when it got the previous chip as that isn't how the factory marked them.

The 28 pin program is an improvement with the idle increased to 880 rpm and an improved map.

[Flat Six]

You have a 28-pin DME, which was introduced (IIRC) for MY 1987. If you ordered based solely on the model year of your car (1986) the 24-pin chip you received would've been correct. Guess a PO installed a later DME; I wouldn't be too critical of SW for this and I'm confident he'll make it right.

[Steve W]

Your car starts and runs with the new chip right? Judging by the type of capacitors used on that board and the jumper configurations, that is a typical DME from the 85-86 vintage, so your unit is likely original, but someone previously tried to change to a 28 pin configuration as the later 88-89s, but did not complete the conversion properly, as evidenced by the lack of a corresponding jumper at B700. So the unit continues to function just a unmodified 86 unlt. So just leave the new chip in the socket just as you positioned it, close it up and just drive it.