Here's a link for anyone looking to do a DIS swap. Easy swap, really. https://www.thirdgen.org/forums/dfi-...=1#post3646515

 

I did this with Buick V6 engines as well. The pictures look exactly like the wiring diagrams from my GM Fuel Injection manual from 1996. Interesting...

 

What's the benefit of DIS over distributor?

 

3x00 heads

Just so everyone knows, a 3.1 with 3400 heads is only 11.14:1 compression. Just need a crank postion sensor now, hint hint.

 

Also more accurate timing, never having to set base timing again and less stuff to spend money on (cap, rotor, dizzy, ect.)

 

There's a major component missing from that, and is the largest reason people have not swapped to DIS from dizzy, and that is the crank trigger. If you have a 3.4, this is not a problem, but a 2.8 or 3.1 does not have the provisions for this.

Also it's a 7x reluctor ring, not a "3x" as mentioned in that thread. There are 6 equally spaced notches and one home signal 50* before #4 TDC IIRC, but I'll have to check the location of that home signal again.

If you go back to some of my old posts (probably from my old account as "The_Raven"), you'll see that I had said that this simple modification in wiring should have worked. I would have tested it long ago, if my truck was already EFI when it was built, but since I had toi convert it anyway, I just used the FWD ECM and MEMCAL from the start.

 

I've seen it called both. In literature as well as forums.

Doesn't the ICM fire the pair each time? ie the home notch would be just before #1 and #4 simultaineously?

Also if you used the FWD ECM, did you need to use a 3.4 or FWD crank pulley for that sensor?

 

In any official or highly technical (as in FSM or similar) manuals, that I've looked at, it's refered to as a 7x.

Like I said it's been a while, but I think we figured out it was in refernce to #4 for some reason, though that should equate to being for #1 as well.

I used the 2.8 harmonic balancer and crank pulley. My grandfather and I made a crank trigger that mounts like an MSD crank trigger.

If you are thinking that the 24x pulley mounted reluctor ring is needed, it's not, at least not for the OBD1 FWD ECM and set-up. The OBD1 FWD ECM or EFI system rather only needs the single 7x crank trigger for the ignition.

 

That confirms my suspicion that it's for SFI, like the extra cam lobe.

 

Yes, it is. The 24x sensor is supposed to shorten the crank time. :roll:

The cam positions sensor is strictly for the SFI. Without triggers from this sensor the SFI PCM reverts to btach fire and posts a CEL.