Dahl owners, change your filters
 

Just a reminder to change your filters if you aren't running a vacuum gauge. My Dahl 100 creates about a 2 inch of mercury vacuum at idle with a clean filter. I looked at it the other day because I could hear air cavitating in the pump and it was pulling something like 22. Yikes. Changed the filter, eliminated the cavitation sound (might have been drawing air at the fittings/clamps), and now I am back to 2.

Don't forget to burp it either!

https://www.ford-trucks.com/user_gal...id=102757&.jpg

"Lonely old post" reply guy here:

Mine gets changed about once a year, just before I go "east".

I'm using a two-micron filter in there, and the stock fuel bowl's filter stays spotless!

I now wonder if a gauge wouldn't be a good thing for me to add.

Pop

If pre-pump filtration was stock on these rigs, the biggest advice on the forum would be the after-pump fuel filter... or "Post-Pump Purifier".

In answer to your question, the vacuum gauge pre-filter and fuel pressure gauge post-filter would give interesting information... but it's not idle where the issue is.