Materials and Electrical gurus ... here's a question

[parsonsj]

When I originally put my car together, I had a *lot* of problems getting two CPUs to talk together (Holley Commander 950 EFI controller, and MSD's LS1 Spark Controller).

After fighting the issue for weeks, I gave up and converted everything over to FAST, and got everything running.

That was a year and a half ago. Today I discovered (I think ... I'd love to have somebody check my facts) that stainless steel has about 100 times more resistance to electrical current than copper, and 10 times as much as ordinary steel.

Why does this matter? Because I used a SS stud to ground all engine components. I was worried about corrosion, and didn't have a copper stud handy. I put the stud through the firewall, and tightened it in place there with SS nuts. Then I hung all the grounds from there: engine block, battery, ECUs, sensors, etc.

Could that have caused my odd ECU/MSD problems?

Thoughts?

jp

[matty b]

that possibilty is slim and none the problem, id suspect a mix match in crank trigger signals being requested and sent. the 950 wanted one thing and the msd box was spittin out something different. thats my guess at least. just wondering are your grounds tied to the same stainless steel bolt again?

[OHCbird]

If the current loop through the stainless was common, then the likelyhood of noise from that connection is low. The MSD has a noise isolation circuit on it's input and output anyway. Did you ever see what the reference voltage was? I had heard that if the MSD saw a 1-2.5vdc float on the input, it would make it 'stupid'. My old pertronix ignitor did this too me once (my fault).

Despite having 100x the resistance of copper, stainless is still in the 'good conductor' list in most apps that need corrosion protection. We can't all have gold plated contacts everywhere!

[parsonsj]

OK, guys, thanks. It was just a thought, and not something I can do any more experiments with (both devices have since been sold).

Yeah, all the grounds were tied together. I connected all the grounds to the 1/4" 6061 mounting plate that held the devices, and then connected that plate to the ss bolt. The bolt was where the battery, block, and all the grounds met up.

The MSD was supposed to provide a tach input to the 950. The funny thing is that the car would start every now and then. Say 1 out of 10 times. It was a very frustrating thing, and something I've never figured out. After moving over to the FAST XFI, I had the car running in 3 days.

jp

[matty b]

yep definitley not a ground issue. too bad the stuff is gone I find it fun to help figure out those problems.