My Dresser TD 7G has developed issue of starving in cycles. It will run fine and then run down to low idle before running up to full rpm --repeatedly under load. No load -- it will take longer to act up. Does NOT die, just runs down to low idle before reving back to set. Have done all the basics--new filter, checked fuel quality--bright red, have full flow from tank to fuel pump (which has less than 40 hours on it), bled air out past the pump. Acts like there is a vacuum being created somewhere in the system, but have eliminated all that I can think of or identify. THANKS for any help.
When acting up , you ever take the fuel cap off to check for vacuum ? Just thought I'd ask.
That was the first try and that used to be a problem. Thx.
I had a backhoe doe the same thing (New Holland) and the problem turned out to be algae in the filter. Sounds like you checked that. I would definitely agree its a fuel supply problem, probably before the injectors. I might check the lines for any clogs next. Then, unfortunately, I'd say the pump might be going?
I believe those have a banjo bolt with a screen in it on the inlet to fuel filter and lift pump.. Can't picture a G exactly..
I have seen fuel lines that give good gravity flow when checking have an internal layer collapse and pinch off under the lift pump vacuum. Made the machine act like you discribe.