Re: More problems... \'89 Burb stumbling off idle ***UPDATE***
Well, it sure appears that there's a strong vote against performing a very simple and cheap procedure to see if it reduces or eliminates the stumbling problem. I thought that's what our poster was asking for.
I don't have a clue of what to do in terms of running down ignition and fuel delivery problems with TBFI computer controlled engines, and I respect anybody who does. I was just trying to offer some help to a guy who noted that he'd bought a truck that had sat for a year, and my experience with old trucks and boats told me to suggest that bad fuel may be some or all of his problem.
Dorian, my boat, as with millions of others, does not sit in a 100% humidity environment all of the time. For the last 16 years, my boats have sat in my driveway, on it's trailer, much to the disappointment of my wife and neighbors. Irrespective of evaporative systems in trucks, I doubt they work very efficiently while the truck has been sitting for a year. While it's running, sure.
In fact, two stroke outboards, four stroke outboards, four stroke stern drives, four stroke inboards, marine diesels, and all types of marine and automotive engines are exactly the same when it comes to requiring clean, stable fuel. The vessels and vehicles which sit for a period of time with untreated fuel in the tank can suffer from a variety of operational problems, usually manifest by poor running conditions. I have personally owned one truck and one boat which idled just fine but would not power up until the fuel filters were changed, fresh fuel poured in (following the draining or siphoning of the stale fuel), and stabilizer run through the idling engine along with the fresh fuel to clean out the crud in the fuel delivery system.
In the past year I've pulled two tanks from Scouts in order to steam them and POR them. Varnish is my constant companion. I'd sure as heck pull a boat tank if either me or a prior owner had been foolish or ill-informed enough to leave untreated fuelin it for long enough for varnish to form. I have no idea how long that takes, but I have not suggested that it's within the 40-60 day period I suggested as a shelf life of untreated gasoline. That period, as I've read elsewhere, is the period after which the fuel begins to break down and becomes of poorer quality.
So, leave the untreated fuel in your power equipment, boat, or truck as long as you'd like. No skin off of my nose. If you're looking for a proven way to prevent some fuel related problems, or cure some, try stabilizer and/or store and start additives. It's cheap, easy, and requires no tools or diagnostic equipment or skills.
Dan- Congrats on getting the old girl going. Going back to the beginning and reviewing everything you thought to be correct and true is sometimes the way to find the problem.
Let's keep these future classics on the road, and off.
Foy
