D-Jet: Can you compensate for Throttle Shaft air leak? Options

[jrmdir]

After months of chasing a rich condition on my '73 1.7 I decided to once again try pressurizing the system and applying soapy water. Glad I did because I found two more leaking hoses and a leaking Cold Start Valve gasket. But the worst culprit turned out to be a leak around the throttle shaft.

There are a number of threads about options for adding bushings and or seals, but am I right in thinking this would mainly impact idle mixture? If so, I'm wondering if other system adjustments, e.g. ECU knob and/or MPS could overcome the effects of this leak - at least until I find a machine shop to fix the TB.

Thanks in advance for any suggestions.

Ron

[jrmdir]

Thanks to everyone for the great input.

I had a DOH! moment soon after I posted that when I realized what I already knew, that - as has been pointed out - any extra fuel added by the MPS due to vacuum leaks would only raise the RPMs - just like multiple tiny extra throttle openings - not lower the A/F ratio.

I think I was so excited to find the previously unknown leaks that my brain just wanted it to be true that this was going to help fix the rich condition (IMG:style_emoticons/default/smile.gif)

But it will indeed help to take these variables out of the picture so I can hopefully improve the idle situation and keep working on other things that do impact mixture like MPS calibration and CHTS replacement.

Thanks again!

Ron