Tortuga

I've followed with great interest the ECU Capacitor thread since I have both a 96 and a 97 LS that we drive daily.

I just took a few minutes to do Yamae's ripple test -- thanks Yamae for posting!

Here are the results

97 LS,
163k miles
Garaged in DC area since birth, so hot humid summers and cold-ish winters
Slightly sluggish when cold, not too bad when warm, and no other issues
85.5 mV, engine cold

96 LS
78k miles
Summers in NY state, winters in Florida and car seems to have been garaged.
Occasional slightly rough shifts, but otherwise seems to drive as new
79.3 mV cold.

Both cars are well maintained - I have the records for both.

I'm going to pull the ECUs soon to do a visual, but these numbers seem way over Yamae's limit of 40 mV RMS, although my symptoms seem pretty benign so far. I'm a long way from my ee courses in college, so it's possible also I screwed this up.

Does anyone else have any ripple test results they can share? I'd be curious to see what others have measured to see if there's a limit at which the car becomes a basket case due to the caps.

LScowboyLS

Sounds like both ECU's are OK for now, just be sure to do the physical inspection as well (I would use a dental mirror and light to check the undersides of the caps, where the leaking begins, for an oily glossy look), because you need to do the fix before any leakage destroys the circuit traces of the bottom board!

As a further of the ECU caps fix, if the correct rare caps in the links in post #1 of our thread are used, most people are reporting increased low end power and silkier shifting!

Just keep in mind that you will likely be doing the ECU caps job in the next year or two on both cars, as these are two of the most affected years, so it's not so much a question of whether the caps will fail, but when.

Yamae

Judging from your EE degree,I bet you must have a very good multimeter.
A good one shows bigger because the frequency response is better and accurate.

Look at the photo below. My Fluke 8060A shows bigger ripple voltage although I am measuring the same China made switching DC power supply unit.

There are many happy LS owners like RA40 or Dutchy who replaced capacitors as a preventive measure. The result showed the improved engine and shift performances although they were not noticing any particular problems before.