Looky what I found on Ebay

[granit_silber]

Seems just a little too good to be true.
-ashley

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=32094&item=7951910796&rd=1

[biondani]

Don't bother, I've had experience of this sort of stuff before. I stupidly bought one out of curiousity for an old car and all I received was a resistor (worth approx 1cent) and a photocopied sheet of instructions for a different car.

Ian

[granit_silber]

Don't bother, I've had experience of this sort of stuff before. I stupidly bought one out of curiousity for an old car and all I received was a resistor (worth approx 1cent) and a photocopied sheet of instructions for a different car.

Ian
I definitely wasn't going to do this. I just can't imagine 1) how it owrks and 2) how so many people have bought these things.
-ashley

[dternst]

If it seems too good to be true... then it is.

[gale]

I've played with various resistor values on mine in persuit of a smoother idle & it helps a little bit, can't say it does much for performance, certainly not a 20 hp gain as claimed. What they're doing is putting a resistor in series with the temp sender to increase the resistance, "tricking" the DME into thinking the engine is colder than it really is, thus letting it run the fuel mixture a little richer. If you check Bentley's, he gives the values for the sensor:

270-400 ohms at operating temp (approx. 176F)
2100-2900 ohms when cold (approx. 68F)

Mine idles smooth as silk when 1st started cold but still has a bit of a rough idle when warm, even with the valves adjusted spot-on, new plugs, cap, rotor, etc., fresh dose of fuel injector cleaner. I measured it at 170 ohms after a romp on the interstate, with the temp needle at 12:00 O'clock (approx. 182F), so I put a 100 ohm resistor in series with the temp sensor on jumper leads. It smoothed the idle some & I did notice a very minor increase in mid-range pull, so tried a 220 ohm resistor. That smoothed the idle even more but seemed to degrade the power so I went back to the 100 ohm & soldered it in semi-permanant:

http://www.nmia.com/~dgnrg/dme-r1.jpg

http://www.nmia.com/~dgnrg/dme-r2.jpg

This was actually a factory issued tech bulletin back in the mid 80's for e24's that would lean out the mixture to the point of stalling when warm at idle. The dealer had a "kit" which was nothing more than a 220 or 270 ohm resistor & slip of paper for instructions. I have the actual part number tucked away somewhere in all the mess in my computer. I stumbled across it thru www.big-coupe-groupe way back when, when I was having a random stall problem with my old gutless e28 528e.

If you care to dabble with it, just go to Radio Shack & get some metal film resistors (more stable than the old carbon resistors) and do a little trial & error runs with it & solder in the one that works best. 1/2 watt resistors are more than adequate.