Can anybody tell me why the 97-98 XX has a TPS on the carbs?

Ignition?

How does it work?

Is it used just for adjusting the timing?

Will it run with the TPS unplugged?

Thanks...

It's so your computer can more accurately adjust the advance on the ignition timing...& no, it won't run very well without it...if at all.

So can I adjust it, or install a resister or something to get more ignition advance?

Probably not, as the ignition relies on throttle position for it's algorithm, it's likely more complicated than a simple value for RPM vs. throttle position.

An ignition advancer, which is a different rotor on the crankshaft that alters (fakes out) the crankshaft position from stock, is the easiest way to achieve a different base ignition timing advance.

97-98 birds do not have a knock sensor, so there is no way for the computer to adjust for the onset of knock. As such, it's a good idea to run high octane fuel, at minimum, and verify that the engine doesn't knock under load with the new advancer.

J.

I originally went with the 4 degree advance, then went to a 2 degree on my 97.

I noticed a knock in the higher altitudes riding up to Lake Tahoe with the 4 degree, even with 91 octane. Switched to the 3 degree and no more knocking.

It was only really noticable under hard acceleration, and only for a second or two, but it was enough to spook me, so I switched back.

Could you tell the difference over the stock setting?

You could buy my Dyna 2000 and set the timing were ever you wanted and it doesn't use the tps. :twisted:

The roll-on had a bit more snap on both settings. I think if I had access to the good octane stuff, I would have seen more with the 4 degree, but I had visions of pitting my pistons and took it off.

So, do you want to sell it?