Itinerant Air-Cooled

Last summer, had my TSII come loose (again!). Although this time I think I actually got it tightened down correctly (Colin and I had to retap a new hole for it). Took it out afterwards, and the bus just didn't seem to have the power, esp. on the expressway....seemed like it was 'gasping for air' (fuel?) and the gas mileage went from 17ish to 14ish. I richened it up two notches on the FI. Seemed better, and mpg increased to about 16-18ish. We drove it out to Ann Arbor today, and of course, before I drove it home, had to richen it up two more notches. Now it has the power I would expect it to have on the freeway, and mpg did not change.

Point of the story, if you don't have a correctly grounded and functioning TSII, and then fix it so it works properly, be in-tune to how your bus runs, as someone may have changed settings to compensate a poorly functioning TSII.

TrollFromDownBelow wrote:Last summer, had my TSII come loose (again!). Although this time I think I actually got it tightened down correctly (Colin and I had to retap a new hole for it). Took it out afterwards, and the bus just didn't seem to have the power, esp. on the expressway....seemed like it was 'gasping for air' (fuel?) and the gas mileage went from 17ish to 14ish. I richened it up two notches on the FI. Seemed better, and mpg increased to about 16-18ish. We drove it out to Ann Arbor today, and of course, before I drove it home, had to richen it up two more notches. Now it has the power I would expect it to have on the freeway, and mpg did not change.

Point of the story, if you don't have a correctly grounded and functioning TSII, and then fix it so it works properly, be in-tune to how your bus runs, as someone may have changed settings to compensate a poorly functioning TSII.

Yes.
A poorly grounded TS II will fake out the ECU into thinking it is cold, runs the mixture rich:
a) maintenance professional then leans it out.
You tighten it, ECU then leans out the mixture as it correctly reads a warm engine, ergo!
b) you need to compensate for aforementioned maintenance professional's incorrect compensatory adjustment.
Colin

Thanks Colin! your response gives me comfort that my 'seat of the pants' diagnosis was correct.....i really wasn't sure if it was poorly grounded would make it run lean or rich. She is running really good though....and ah yup....still the same spark plug we cleaned and gapped 20k miles ago holding it's death grip on the helicoil. figure if I keep the ignition system running correctly, so the sparks are hot and bright, the fuel/air mixture in the right range....who knows...may go another 20k miles.

TrollFromDownBelow wrote:She is running really good though....and ah yup....still the same spark plug we cleaned and gapped 20k miles ago holding it's death grip on the helicoil. figure if I keep the ignition system running correctly, so the sprarks are hot and bright, the fuel/air mixture in the right range....who knows...may go another 20k miles.

Glad to know I'm in good company! Loctite and a prayer has gotten me through some tough motoring scenarios this season…
Robbie