Thomas bus MVP er 2000 clogged diesel

[Letsbenomads]

Hi everyone,

We think we have a problem with our diesel filters. The engine dies as soon as I use the gas pedal. It starts and idles fine, reverse is also not a problem. I changed the two fuel filters at the engine, but my contacts say the problem is likely to be the strain filter inside the fuel tank. Or could it be the turbo or vacuum pump? We put our floor over the opening, because we thought we wouldn't just it. Now I am trying to locate it and figure out if that it is the way to go in the tank. Any thoughts? I located it through our old drawings and we think the opening is a square of 26cm by 26cm and straight over the tank.

Thanks a lot

[chev49]

you have to determine if you have fuel up to the filters... if not, u gotta work backwards as it can be simple as plugged line. and of course, if you have fuel up to filter at the connection, u work your way forward of course. there is more than one way to check without removing the tank,

[Rusty]

Originally Posted by Letsbenomads

Hi everyone,

We think we have a problem with our diesel filters. The engine dies as soon as I use the gas pedal. It starts and idles fine, reverse is also not a problem. I changed the two fuel filters at the engine, but my contacts say the problem is likely to be the strain filter inside the fuel tank. Or could it be the turbo or vacuum pump? We put our floor over the opening, because we thought we wouldn't just it. Now I am trying to locate it and figure out if that it is the way to go in the tank. Any thoughts? I located it through our old drawings and we think the opening is a square of 26cm by 26cm and straight over the tank.

Thanks a lot

Wooa. Slow down. Fuel filter or turbo? Sure is a lot of stuff between those 2 pieces.

Transmission ok?

What other weird stuff have you noticed? as in - right before it did this, this happened or it's been sitting 4 years...etc.

My fuel tank does not have a in-tank filter- 2003 BB. Like others have said, you need to do the flow test in a glass jar. Hold-off on dropping tank. They sell USB endoscopes on amaz for $20- shove it in fuel schnozzle and take a peek.

[Letsbenomads]

Hi, thanks for your replies. At the moment I am trying to figure out how to access the straining filter in the tank and if I have one. Is it from the top attached to something? Thanks

[Letsbenomads]

Ok, so today we did a climb of 400m in first gear and then it shut down again. The engine is not overheated, it just stops.

So far we have:
- changed the two fuel filters, still no idea where the strainer in the fuel tank is, probably at the bottom.
- a mechanic took off the regulator valve of the turbo and it was stuck, even with pressure of 1,5 mbar. He was no truck mechanic but he thought it should move with 1mbar. He did get the part it was attached to to move and we did to test runs from sea level to 220m, both runs were good. Now I am at a steeper climb and after 400 height metres it died again, without any signs. It feels like it is running a lot better, but still dies..
- I am letting it cool now for a bit and we'll see happens, still not how it normally goes during climbs.

Any suggestions would really help!

Thanks

[Rusty]

What does Capt Squid say? He is our resident MVP expert.

Are you certain there is an in-tank strainer? Can Thomas provide a part number or do you see it on a schematic diagram?

Was there a lot of crap in the other filters, or relatively clean? Was fuel funky/old?

Did you check fuel cutoff kill solenoid on motor? I have ziptied mine back when unsure if culprit to test. Careful here...

Running fine, cuts-off doesn't sound like starving for some reason.

[Letsbenomads]

Sorry, I am not super familiar with the whole mechanics of the bus, I am learning at lot though, the bus brakes down quite often unfortunately.
What is the solenoid thing? Where can I find it?
The filters weren't very dirty. Fuel looked ok. We are not sure if there is a stainer and have not gotten an answer of Thomas bus.

[cowlitzcoach]

Out of curiosity, has anyone taken the fuel cap off to see if the vent is stuck? If it is stuck it will have a terrible time sucking fuel up to the engine once you are below about 1/2-tank. If it is stuck, when you go to release the fuel filler cap it will be very difficult to loosen. And when you do it will just about suck your fingers into the tank.

In most cases, if you are running out of fuel it is something relatively simple.

[Rusty]

Side of engine behind fuel injection pump

not best angle, but 2" cylinder about 5 inches long with a plunger and rubber boot on end. 2 or 3 wires coming out of it.

[Rusty]

more reading...

[Letsbenomads]

Ok, so I thought this was only happening in the lower gears when going uphill, but after that initial climb yesterday I was able to drive 90 miles downhill without any problem and after 40 miles slight up and down it died again suddenly, I was definitely in the higher gears then..

[Letsbenomads]

It also died with a full tank and it is easy to take off the fuel cap.

[Letsbenomads]

Rusty, the more reading link doesn't seem to go to anywhere and does every engine have a solenoid thing?

[chev49]

you never said if you checked the fuel supply line before the primary filter.

[Letsbenomads]

How can we check that?

[Letsbenomads]

How can we check that? There is no diesel leaking..

[Tango]

BTW...the simplest and cheapest fix for a bad fuel solenoid on a B series Cummins is to...remove it. Just replace the expensive (and often problematic) electric solenoid with a push/pull rod. You do have to remember to turn the fuel on and off but it totally eliminates one of the weak links on an otherwise great engine. Many, if not most, older diesel engines were set up that way (my old Detroit 6v53 for example).

My new 4BT is now that way. I removed a perfectly good solenoid just to avoid that issue from ever coming up.

[Letsbenomads]

The new plan is to cut the two pipes that come out of the electric pump and put a garden hose on it that goes directly into the fuel tank and try the pump and see if the filter gets fuel, now it didn't. The mechanic thinks the electric pump should work, he was listening closely to it.

[CaptSquid]

Rusty, I have a Cat C7. Besides that and changing filters, I know absolutely NUTHIN' about no diesels.