Another prime issue.

demodriver · September 18, 2011, 05:54:35 PM

Quote from: gus on September 18, 2011, 01:41:12 PM
Which brings up another point, was the tank near empty the times you had the problem?

That would increase the possibility that tank junk is causing the problem.

If this is really the problem a couple of filter changes will usually stop it. Same thing happened to me when I first got my 4104, it would clog the primary filter in less than a thousand miles.

The first time it happened I did let it get low on fuel. The second time it had about 3/8 of a tank. I drive my bus alot (about 800 miles a month) and used to run it down lower without any problems. I have been driving it for about three or four months without this problem. I will still be changing filters and checking other things out.

Eric

luvrbus · September 18, 2011, 06:58:59 PM

Dallas gave you some good info but I never had problems with filters on idle it affects the higher rpms for me

good luck

TedsBUSted · September 18, 2011, 07:35:40 PM

I wonder if the "splashdown" caused by fuel from a station's fast-dumping filler nozzle hitting Demodriver's low tank isn't causing temporary foaming or aeration problems, which bring on the loss of prime.

Of course a tank that's low on fuel has less head pressure, so any fuel suction issues are exasperated, but then again, 3/8 tank doesn't seem so very low either.

Ted

demodriver · September 18, 2011, 07:42:29 PM

At last fueling we let the bus sit for about 15 minutes before refiring it. We took time to wash the windshield and I walked to the other side of the truck stop to buy gas. I would think that most of the fowm should of settled by refire. How long do you think it would take to settle out?

Eric

TedsBUSted · September 18, 2011, 08:02:08 PM

With the settling time, and since the engine was stopped during fueling, I'd say that sort of blows my aeration theory out of the diesel.

Ted

Just Dallas · September 19, 2011, 11:41:42 AM

Hee Hee, I never did either until I changed the filters on BK's Setra a few years ago, it ran fine until he got out of the drive and down to the main road, then as soon as he started to go, the darn thing went tittsup. He called, Gene grabbed me, I grabbed my filter wrench and we headed down to fix it. It took about another 3/4 turn to make it seal completely.
Talk about embarrassed.... I still have no idea why that happened.

Quote from: luvrbus on September 18, 2011, 06:58:59 PM
Dallas gave you some good info but I never had problems with filters on idle it affects the higher rpms for me

good luck

gus · September 19, 2011, 01:05:10 PM

I had the same loose primary filter problem once on my 4104, it ran fine until I came to a hard climb, then it would start sputtering. A slight tightening of the primary filter bolt (original non-spin on type) stopped that.

AndyG · September 19, 2011, 01:29:18 PM

I wonder what would happen if you left the engine running during fill up?

demodriver · September 20, 2011, 07:15:39 AM

That is my usuall practice and has always been my practice on my tri axles that I drove. On my other thread when I first had a problem one suggested that with low fuel levels it may be foaming and sucking air boubles. So I shut it off this time.

bigjohnkub · September 20, 2011, 07:44:49 AM

Last year on a 1500 mile trip, I had the same symptoms. After checking fuel, ect. My bus started and ran the rest of the trip with no problem. O.K., Air in fuel. This year in June, 150 mile trip. Refueled ten miles from Home, died going in gate. Attempted to bleed, wife could not get engine to crank . When ii walked to toll window, reached in and hit start, engine would crank over. Started up with bleed cap off filter.
Later in year, due to fires and 60 mph winds, was going to move from parking spot under trees. Flipped on toggle switch, all buzzers came on, hit start button and everything went dead. waited about 10 minutes and started up.

short explanation. Faulty circuit breaker. Changed breaker and poroblem has gone.

Big John