Have a driver picking up a rv in Phoenix. Motorhome will only go 65,pedal to floor. Is there a governor?? If so,is it adjustable?? Also he said it slows to 45-50 up hills. I know usually a cummins pusher does not do this. He is traveling 3500 miles. Any help appreciated. Also,when he arrived to pick it up.it would only click when turning the key. Had to turn key on,and use a remote starter to start it. Any ideas??? Thanks, Gil

 

Im no motorcoach expert but I would say that might be all you get in stock form. The trucks have 3.55 or 4.10 gears. my 93 350 4x4 with 3.55 would not do past 80 mph. with who knows what gearing your coach has it might be running up against the govener. I would look for a gear ratio on the diff cover. There is much you can do for HP but a pyrometer first would be wise. I would imagine the coach is pretty heavy. I would change the fuel filter and check the air filter for starters. More info would be helpful for the experts here.

 

First we need to know is what engine does it have , if it is a electronic engine , it could have a global speed setting of only 65 and would need to be reset with Cummins Insite at Cummins. or if Mechanical engine , find out what the rpm are at top speed. the old B were govern at 2700 rpm

 

If it's the big class A it's probably got the L10 300hp Cummins. If I recall, I think the governor is located on the back of the Injection pump and they are adjustable. If you can only start the coach with a remote starter, then I would say there is were your problem lays. I think I would start by removing the remote starter, repair the wiring harness and then go from there. Has it been sitting for a while? You may have some bad fuel and or plugged fuel filters.

 

well most likely if it is a 93 , and has a L10, it will be a celect engine , if it is a 5.9 or 8.3 , it will be a mechanical. the remote starting is most likely a relay problem.

 

You may want to check so see if accelarator pedal is pulling the lever to the high idle stop. If you have a cable type, these do tend to stretch. Just my thoughts. Thanks Steve B.

 

The Coachman, if it is 36 foot or less, it should be a B series 5.9 with a mechanical P pump injection system in either a Spartan or Oshkosh chassis. If it is the 38 or 40, it will be the C series 8.3 with the hybrid pump.

With either one the first thing to deal with is the synthetic fuel hoses and filters. On all motorhomes it seems to be a some kind of law that routine preventive maintenance is never done. There will be two fuel filters, one up on the engine, and another somewhere in the fuel supply line and usually located right in the open by the radiator or rear access panel. Almost always the line filter gets serviced, but the engine filter is likely the original, as no one bothers to pull the rear bed and lift that cover to do the service.

You may well find the original fuel hoses on the system too. There are about 25-35 feet of them, so be prepared to replace them all. Do both the fuel feed and the fuel return hoses. I have yet to meet a motorhome owner that bothered to replace their fuel hoses.

Then on the B series you will probably find the old style injection pump overflow valve on the inside of the injection pump. Replace that with a new two piece valve from Cummins. This can get tricky. The B series engines have a larger injection pump than the engine used by Dodge, and you many times have to grind a relief in the head above the overflow valve to get it out for replacement. If this is not something you or your guy knows how to do, take it to a shop. It is critical that no metal grindings or dirt get in the fuel system, so this takes a bit of care. Priming the fuel system on a motorhome is always a real pain in the backside, so be prepared to crack injector lines open to get it started again.

If it is the C series 8.3 engine in the larger chassis, it will be necessary to get it to a Cummins Service Center (or other qualified diesel shop) if it is not the hoses or the filters.

The next thing to look for is a split intercooler. That is real common on motorhomes, and can be found by putting the coach in gear, holding the brakes locked, and reving it up against the torque converter just enough to allow the turbo to start winding up. Only do this for a few seconds at a time to avoid torque converter damage. If you hear a hiss around the intercooler, then trace the crack by using a lot of very soapy water and soaking everything while the rig is at idle.

 

Thanks for all the help guys. He is almost home now. It still is running at 65 max,but is reliable so far. It is a 32 footer,so i guess it should be a 5.9. I will check it out this weekend,when it arrives. Will let you know what i find. Thanks to all. Gil