Starting a Diesel Pusher

[BigSwampgator]

When I start my Cat 300, do I push the fuel pedal all the way down?

I'm not doing this and it seems that sometimes it takes a while to start.

What is the normal process?

[wolfe10]

Bigswampgator,

Welcome to the FMCA Forum.

Assume you have a Caterpillar 3126. If so, not you do not need to apply throttle to start.

Turn key to first position until "wait to start" light goes out. If below 40 degrees, a good idea to turn key back off and back to the first position again. This position turns on the intake manifold heater.

Then start. If house battery bank is fully charged, using the boost switch will help, as it gives more battery amp-hrs to the starter and intake manifold heater.

And, if you have shore power, turn on the block heater if below 40 degrees. Even an hour or two helps.

[vandyk]

I have a 2005 Alfa with a c-7 350 hp Cat. The manual says to turn key to first position for manifold heat, it then says before you crank engine to press throttle to the floor and release. It then says when you crank engine to depress throttle about half way until engine starts. Seems to work well for me, I also agree with Brett to use the block heater as it seems to start quicker.

Neil Van Dyk

FMCA442182

[wolfe10]

Yup, we are speculating on exactly what engine you have-- 3126, 3126B, 3126E or C7. With model years ranging from 1996 to 2008. Several different renditions during that time period.

Irrespective, your Caterpillar owners manual is the place to look.

If you don't have one, you can order one from any Caterpillar dealer (you will need your engine serial number).

You could also call the Caterpillar RV Hotline with your engine serial number and they can look it up for your exact engine: 877 777-3126.

[BigSwampgator]

Thanks for your help.
Found the Manual. It is a C7.
It states the following: "Do not push the throttle or do not hold the throttle downward while the engine is cranked. The system will automatically provide the correct amount of fuel to start the engine. If the engine does not start after 15 to 20 seconds of cranking, release the keyswitch." "Allow the starting motor to cool for two minutes. Then repeat."

That is the way I have always done it. But I was nervous on most recent trip. Last year the engine would not start. A service tech had to come to my house to check it out. His computer showed the the fuel pressure had dropped at a valve. He had me crank for a long time while the pressure built up and the engine eventually started. He told me that this was a common problem with this engine. I had the valve replace.

On this trip, while starting one morning, I may have caused a problem when it didn't immediately start. Because I was nervous I hit the throttle and it wouldn't start. I waited a while and tried again. Had to crank a while but is started.

My lesson I guess is that I should just do it the way I always have (according to the book) and not worry about this fuel valve.

Again thanks for your help.

[wolfe10]

I suspect the valve you are talking about is the fuel check valve in the return line at the back of the head. It connects to the fuel return line going back to the fuel tank.

Easy to replace (couple of minute job) and, yes, particles can hold it open which allows fuel pressure to drop. And, as you have found out, with no fuel pressure, no start.