When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It's really not that hard to re-curve a distributor, I'll bet you could teach a little kid to do it.....essentially, you just measure timing advance at different rpms with a timing light, and do a little simple math, I'm talking SIMPLE MATH here, addition and subtraction. Fiddle with the mechanical advance springs till the curve is the way you want it, and PRESTO! Ladies and Gentlemen, allow me to introduce to you.......a recurved distributor.
It sounds to me like fuel starvation. Is it only stumbling when you are asking for high fuel delivery, that is what I got from your post. How long since fuel filters were checked and screen in tank, how about the fuel pump?
I agree, typically fuel starvation symptoms.
As long as the engine is running OK on idle and cruising but then hesitates and backfires when you stomp it it is fuelrelated.
I'd suggest before you pull the distributor and start recurving, etc., fix your original problem. Start by draining your old gas and using it for your lawnmower or something. Put in fresh gas with Seafoam, as suggested, and see if that does it. If not, move to fuel delivery and replace your fuel filter. Move along in small easy steps until you track down the problem.
When it's solved, then you can recurve your distributor and whatever else you want to get into. Good luck, and let us know what solves your problem. It helps the rest of us, too.
Duane
Your DUI should have a serial number on the bottom of the base. Have it handy when you contact them and they should be able to tell you if it is curved for your application. The advance specs are on the documentation that came with the dist., not on the base...
Hook up that vac. advance, it's there for a reason.