Please help! Losing power

Zndrson · 09-10-2016, 01:52 PM

Hey guys, just bought a bus in Arizona. Didn't get but 7 miles away on the highway and my dt466 started losing power. Got up to 55 and then went down down with petal to metal. At 35mph I got off highway and am siting stranded. Any advice would be great. Otherwise going to have to tow away and fly back home.

If anyone wants to call my number is 334-seven48-1465

Thanks

Jolly Roger · 09-10-2016, 02:07 PM

Could be water in the fuel? There should be a water/fuel separator underside that you could drain that could help. Another is do you know how old the fuel is that is in it?
All kinds of algae and water that promotes algae can contaminate the fuel if it sits for long periods.
Parts stores sell additives to help with that but it is more preventative than an immediate fix.
I would say drain your oil/water separator, depending on the amount of fuel in the tank? Drain the tank and put fresh fuel in then give it a go again? That's a quick fix without changing filters? Might help and might not.

Zndrson · 09-10-2016, 02:57 PM

Quote:

Originally Posted by Jolly Roger

Could be water in the fuel? There should be a water/fuel separator underside that you could drain that could help. Another is do you know how old the fuel is that is in it?
All kinds of algae and water that promotes algae can contaminate the fuel if it sits for long periods.
Parts stores sell additives to help with that but it is more preventative than an immediate fix.
I would say drain your oil/water separator, depending on the amount of fuel in the tank? Drain the tank and put fresh fuel in then give it a go again? That's a quick fix without changing filters? Might help and might not.

Thanks for the quick response.

Finally got in touch with dealership I picked up from. After thinking they took complete advantage they're getting a mobile mechanic to come out.

Will post what the issue is when I get more info.

Carytowncat · 09-10-2016, 03:29 PM

Sending good luck wishes your way!

And another reason a good 10 to 20 miles test drive is so important.

family wagon · 09-10-2016, 07:35 PM

Did it more or less coast to a stop, or does it still have adequate power to at least maintain a little speed?

The fuel contamination idea is a good place to start. In case it was an algae, sediment, or similar contamination then the fuel filter would likely be plugged up and would need to be replaced. Filters aren't *that* expensive, and it's one of the things you were going to be replacing right away anyway. Right?

Brad_SwiftFur · 09-10-2016, 08:52 PM

With a loss of power, the first thing I would think is "Fuel Filter(s)". These need to be changed regularly, like at least every other oil change (some shops do it every oil change). Does the filter(s) look like it's been changed in the last year or so? Typically, as these begin to clog, you'll experience acceptable power at idle and even around town, but when you need maximum fuel flow - like during acceleration, or ascending an incline - the engine will drop to idle, hesitate, or stumble. It may ascend that slight incline at 20-30 MPH when ordinarily it would run up it at 60+. Once the road flattens out, it may once more resume that 60+.

GreyCoyote · 09-10-2016, 11:05 PM

Your 2001 is similar(ish) to mine. Most diags need a scan tool, but old school methods work in a pinch.

On drivers side of the engine above the fuel filter is a schrader valve. With engine idling, push the stem in. Fuel comes out at a good clip? Good. Next...

Loosen the fuel tank cap a couple turns. Should be a little poof of pressure, definitely not vacuum.

Check the tattletales on the air filter. Should be green. Pull the filter and make sure nothing is obstructing the intake. Reinstall.

On the accelerator pedal is a bulge and a joint (the potentiometer). Rap it sharply with a screwdriver while idling. Did the idle change? If so, replace. (These busses are fly-by-wire. That little pot tells the ECU how much power your foot wants).

Got air (more than 90 psi) in both brake systems? Should be 90 to 120 psi. Less than 35 and the parking brakes come on.

Wish I saw this earlier. I'm enroute from nevada to Texas and likely drove right by you. Best of luck. Five bucks says its something really simple like a control pressure regulator or such.

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