Upgraded DME to 4k for SW Chip. Stock chip work?

[dimeified]

Hello, fast question for the SW guys. I SW chipped my car a while back along with my cat/bypass sport muffler upgrade. I have to bring my car to inspection, and put back on the catalytic converter. I dont feel like going back to the DMV twice, and i've heard sometimes people fail with the SW chip. Can i install the stock chip back in even though i upgraded the dme with the jumper to make it read the 4k chip? Or do i need to reverse this mod?
Thanks

[911st]

Contact Steve.

I belive he told me the jumper mod is of no issue and some DME's already have that mod from the factory.

[Zef]

No need to reverse to 2K.

[slodave]

Not totally true. Early DME's, like mine, can't be upgraded and still run the old 2k chip.

[Zef]

Originally Posted by slodave

Not totally true. Early DME's, like mine, can't be upgraded and still run the old 2k chip.

OK...mine is an early one...and upgraded.(((All 84-86 911s can upgrade to the later 4K program by a simple jumper move and readjustment of the base idle speed. After you make this mod you can still run your old chip without changing the jumper back.))) This one directly from Steve web site.

[slodave]

Originally Posted by Zef

OK...mine is an early one...and upgraded.(((All 84-86 911s can upgrade to the later 4K program by a simple jumper move and readjustment of the base idle speed. After you make this mod you can still run your old chip without changing the jumper back.))) This one directly from Steve web site.

I talked with Steve about this as well. Certain early DME's can't be upgraded to a 4K, and then run a 2k. I tried, it didn't work. Steve then remembered and confirmed that it does not work on the early 84's. I believe chips numbered 1267355028 (mine is) can't run on an upgraded 4k DME. To make it worse, I also upgraded to a 28 pin socket and the 8k chip. You really can't go back and use the 26 pin 2k chip.

Again, not all 84's can upgrade to 4k and then switch back to the 2k chip.

[DRACO A5OG]

Talk to Steve, I purchased a Stock Chip from him for my updated DME.

[Zef]

Originally Posted by slodave

I talked with Steve about this as well. Certain early DME's can't be upgraded to a 4K, and then run a 2k. I tried, it didn't work. Steve then remembered and confirmed that it does not work on the early 84's. I believe chips numbered 1267355028 (mine is) can't run on an upgraded 4k DME. To make it worse, I also upgraded to a 28 pin socket and the 8k chip. You really can't go back and use the 26 pin 2k chip.

Again, not all 84's can upgrade to 4k and then switch back to the 2k chip.

Interesting.....I'm curious and want to know more about it...What's happened when you tried to come back at 2K.....dead engine...?

[dimeified]

Boy does this suck. Guess i'll have to clip the jumper and resolder it after inspection. Whats the worst case scenario if i swap the chips without reverting back? Will my car blow up or will it just not start and everything will be fine once i revert back? I'm tempted to solder in pins in place so i can pop on and off a hard drive jumper.

[DRACO A5OG]

Call Steve, he'll take care of you.