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montanaman42 · 01-19-2014, 12:57 PM

I have a 99 Allegro Bus with a 3126 Cat diesel engine. After sitting for about 2 months, the engine cranks, but won't start. Several other posts in the web talk about fuel issues. Tank is full, been in a protected area. Gauges work, show oil pressure.

loisjop · 01-19-2014, 03:39 PM

If you have an air source take the air hose stick it in the fuel tank with a rag wrapped around it. Crank the air pressure up to 50psi hold as much as you can in the fuel tank while someone cranks the engine. I suspect it lost the prime. You can't hold enough air to hurt the tank.

montanaman42 · 01-19-2014, 08:24 PM

Thanks. I replaced the fuel filter today, still cranks with no start. I will add some pressure tomorrow. It has sat idle before with no problem. Losing the prime would be a new experience in the continuing, or should I say continuous pleasures of MH ownership

????

Mekanic · 01-19-2014, 09:02 PM

Quote:

Originally Posted by montanaman42

Thanks. I replaced the fuel filter today, still cranks with no start. I will add some pressure tomorrow. It has sat idle before with no problem. Losing the prime would be a new experience in the continuing, or should I say continuous pleasures of MH ownership

????

Did your engine have a electric or manual priming pump?
Did you open the priming valve and not close it till you saw a small stream of fuel?

gemini5362 · 01-19-2014, 09:27 PM

Quote:

Originally Posted by montanaman42

Thanks. I replaced the fuel filter today, still cranks with no start. I will add some pressure tomorrow. It has sat idle before with no problem. Losing the prime would be a new experience in the continuing, or should I say continuous pleasures of MH ownership

????

You might have a problem from this in addition to the other problem. When you changed the fuel filter did you fill the new filter full of diesel before you put it on the engine. Did you go to the bleed valve at the high pressure pump and open the bleeder valve. With the bleeder valve open did you go to the manul pump and pump diesel through the system until no air coming out of the bleeder valve. When you change the fuel filter you introduce air into the lines. If you do not fill the filter with diesel before putting it on the engine you introduce a lot of air. This air has to be out of the system before it runs. The trick with the air in the tank is not going to help with this.

Where is your MH sitting. Do you have anti gel additive if it is in cold weather ?

loisjop · 01-20-2014, 08:56 AM

Quote:

Originally Posted by gemini5362

You might have a problem from this in addition to the other problem. When you changed the fuel filter did you fill the new filter full of diesel before you put it on the engine. Did you go to the bleed valve at the high pressure pump and open the bleeder valve. With the bleeder valve open did you go to the manul pump and pump diesel through the system until no air coming out of the bleeder valve. When you change the fuel filter you introduce air into the lines. If you do not fill the filter with diesel before putting it on the engine you introduce a lot of air. This air has to be out of the system before it runs. The trick with the air in the tank is not going to help with this.

Where is your MH sitting. Do you have anti gel additive if it is in cold weather ?

Yes the trick with air in the tank will force bleed the system. Been there done that.

gemini5362 · 01-20-2014, 10:59 AM

Quote:

Originally Posted by loisjop

Yes the trick with air in the tank will force bleed the system. Been there done that.

Where was your advice when I ran my tractor out of diesel and got so tired of pumping the manual that I went and bought an electric diesel inline pump to do that.

montanaman42 · 01-20-2014, 11:43 AM

The saga continues....

Fuel tank is full. No additive in fuel, temperatures in the teens for a week, but in the 40's mostly
Replaced fuel filter and hand pumped until I could not pump anymore
Checked oil level - down below the add, now between add and full (Heui system won't allow the engine to run if oil is low)
MH had been in No Calif, sitting on a level pad.

The last resort - waiting for a Freightliner/Cat mobile repair truck to arrive.

Have not tried the air pressure trick, but am about to.

The good news is that we are with our daughter and family - we just crank out the pinochle and play....

montanaman42 · 01-20-2014, 12:29 PM

Put the air hose in the tank filler, wrapped it tightly with a rag and tried to start. No change in the sickness. Waiting for the vet (Cat Doctor

) to call....

montanaman42 · 01-20-2014, 01:42 PM

I finally found the water separator filter and checked - only diesel fuel came out. I will replace it soon since I just replaced the other filter yesterday. 49r's and MH both lost yesterday

. Suspect Seattle to prevail over Denver.....

montanaman42 · 01-22-2014, 07:27 PM

This will be the end of the thread. The Cat guy arrived on Tuesday am. He eliminated all fuel issues immediately. He connected to the ECM and even though he knew he was connected, the ECM would not communicate with the laptop. He started eliminating electrical problems, tried to find a secondary ECM connection, no such luck. He finally started backward on the power and found a fuse in the battery compartment that powered the ECM. The fuse was good, but when checking the voltage, he noticed a significant drop between the battery side of the fuse and the ECM side - 13+ on the battery side and 9+ on the ECM side. Further checking - the INSIDE of the fuse holder had significant corrosion. Replaced the holder, inserted fuse, and after writing a check, we were off and running. Thanks to Superior Equipment from Newcastle CA. Good service and fair price....