Limp Stillen Supercharger dtc p1239

WhiskeyHotel

Yes, the actual equation is R=Rref(1+a(T-Tref)) and the temp coef (a) of Cu is +0.000393 per degree centigrade. That means the effect is pretty small at the lengths and temps you would experience under your car's hood. (That Bunsen burner temp in your example link is ~1700 degrees C!)

Example: 100 feet of 20 gauge wire with resistance of 1.015 ohms at 20° C (room temp). If the temperature of the wire goes up 10°C, the resistance will change by 0.0399 ohms (10 degrees * 0.00393 per degree * 1.015 ohms = 0.0399 ohms).

The wire resistance will now be 1.015 ohms + 0.0399 ohms = 1.0549 ohms.

In my opinion, that wouldn't be enough change to account for the large increase in resistance your mechanic is seeing. (I think - I don't know what the increase was. I also don't know how the resistance was measured nor do I know which of the conductors he measured and there are grounds, power, and sensor signals going to the throttle body. You can see that I am shooting from the hip here.) My electrical engineering spider sense is tingling at this point. There could be something else going on - connector pins heating up and losing continuity - something. I hope the proposed solution works - but I am a bit skeptical at this point. Let us know how it goes.

Z4fun

If your engine only goes up 10 degree from ambient that would be awesome, unfortunately for the rest of us with a cable sitting directly on an engine with an oil temp of 115+- C your resistance formula would make a large difference if you wanna recalculate it.

The point of my response was common sense with alittle info in heat and resistance for some ppl that don't need a degree to understand it. That's why I didn't have to pull formulas and stuff. The cause was heat and the failure is the wire or connector under the heat stress over a "PERIOD OF TIME" not a one time thing. materials can heat and cool multiple times before getting to the breaking point.

we appreciate your criticism, but would rather appreciate a solution to the problem at hand.

cgr406

So I installed the Michigan Motorsports TB cable about a week ago & wrapped it in teva tape, just cause it can't hurt. No codes / limp mode so far, but it's only been a week. Tonight i wrapped it in thermal insulation from Summit. So, we'll see how it goes, although now that it's November in PA, not sure how much more I'll be able to drive the car for a while.

Attached Images

	TB Cable Teva taped.jpg (97.8 KB, 58 views)
	TB cable heat shield.jpg (97.3 KB, 52 views)

__________________
TopGunZ Rotrex SC / CJM RFS / 1300 / Ecutek / Dynosty / F.I. TP & CBE / Z1 / Swift / SPL / Whiteline / Hotchkis / Michelin SP4

Optimiser

It's been a year so how is it now? More reliable?

cgr406

Yep, so far so good. Although I've only put about 1,600 mi on it. The original stillen cable was OK for a while too, so I'm not sure this is enough of a test to be conclusive. I probably had about 3.5k mi on the Stillen cable before it started crapping out. Fingers crossed.

__________________
TopGunZ Rotrex SC / CJM RFS / 1300 / Ecutek / Dynosty / F.I. TP & CBE / Z1 / Swift / SPL / Whiteline / Hotchkis / Michelin SP4

vqholic@Korea

I also suffered by p1239. Seeing this thread, Hannes was insulated and passed through the summer without any problems. Now that autumn has come, limp mode is back on, and the fault code represents p1239.
It ran about 3,000 mi. Fucxxxx

Optimiser

I'm thinking the only way to fix this problem is to use TopGunz new kit (or piping) that utilizes the stock manifold and therefore stock (length) TB wiring harness.