Community Forums

wolf_7669 · 10-08-2014, 02:38 AM

Hello all,

Just acquired my first RV, a 1985 Mallard 31' on a Chevy P30 chassis with a 454 motor.

The bad news is that on the previous owners last trip in this RV, a fellow camper decided to cut all the fuel lines near the tank and relieve him of a full 60 gallon tank.

When I put in a fresh battery and tried to bring her back to life, she ran for about a minute or so and then sputtered out. I checked the fuel line to the carburetor to discover that there is no fuel getting to the carb when I crank the motor. This makes me think that the fuel lines at the tank did not get hooked back up correctly. And/or the electric fuel pump in the tank is bad, if it has one, not sure if it's an 85 or 85 1/2. From what I was able to see looking at the tank as best I could, I see at least one line from the tank is not connected to anything.

I've been searching the web for a few days now and for the life of me I can't seem to find a diagram of which lines hook up where on the tank. If anyone has a diagram or can fill me in on where all the fuel and vent lines connect on an '85 P30 I'd be very appreciative.

whem2fish · 10-08-2014, 02:46 AM

pump is not in the tank it is above the passenger rear axel along with the regulator and filter

George Schweikle · 10-08-2014, 03:45 AM

My '83 P-30 427 Winnebago had a mechanical fuel pump on the engine. When did the 454 engine come into use?

Quote:

Originally Posted by whem2fish

pump is not in the tank it is above the passenger rear axel along with the regulator and filter

whem2fish · 10-08-2014, 05:25 AM

My 1985 has one the engine and a electric one tied in to the oil pressure switch

QuietWater · 10-08-2014, 11:10 PM

85 was a pivotal year on fuel pumps. More than likely your chassis is actually an 84 since the manufacturers usually bought a bunch of chassis and wouldn't get them all built until the next year. I would imagine that yours did not come with an electric fuel pump unless a PO added one near the fuel tank. You should have a mechanical pump on the motor. There will be three or four gas lines coming out of the top of the tank. One is a vent hose and will not be attached to anything. One is the main line, one is a return line (which you may or may not have), and the fourth is the line to the generator. I assume it does not have the dual fuel option for running propane. It was quite popular during that time period. If so, there is an electric valve next to the carb that must have 12volt power to it or it shuts the gasoline off.

wolf_7669 · 10-09-2014, 01:55 AM

Awesome information guys, thank you.

Now, once i figure out which line is for what, how do I tell which fitting on the tank each line should be connected to? Are there any kind of designations on the tank itself to tell me what line connects where?

And again, thanks for the help guys. I have a little mechanical experience doing routine maintenance and some troubleshooting on the cars I've owned, but I'm a complete noob when it comes to motorhomes.

wolf_7669 · 10-09-2014, 11:03 PM

Made some progress today. Was able to verify there is no electric fuel pump. The previous owner swapped out the stock 60 gallon tank for an 80 gallon and there was no electric pump in the tank. There was also no in-line pump on the frame rail either.

I did discover that there was a 2nd fuel filter on the frame rail between the pull out step and the front wheel. It was dry as a bone too, but it did allow me to attach an alternate fuel source to verify the mechanical fuel pump was good and the engine would run. After a couple squirts of starting fluid, the engine roared to life and purred like a kitten.

So know I know for sure the problem is with the tank. Another thing I did not think of is that 9 gallons of gas in an 80 gallon tank may not be enough to reach the pickup tube in the tank. The RV is pitched a good 6 degrees to the right and about 6 degrees down so all the fuel is at the front right of the tank.

More to follow as I find it out.

wolf_7669 · 10-11-2014, 08:13 PM

She lives!

Thought more about the not being level thing, so I leveled the rv and she started up. Next weekend will be moving her to her new home and getting her all cleaned up. She's been sitting for a good 2 years.

Dave78Chief · 10-12-2014, 09:59 AM

In the files area of the site, under the Chassis category, download the "P-30 Chev Motorhome Chassis Service Guide". It has a section devoted P30 fuel delivery problems and their solutions.

Dave

whem2fish · 10-13-2014, 01:43 AM

dave i knew you would be here i looked at what i had for them but not what i thought i had

Dave78Chief · 10-13-2014, 06:58 AM

LOL - Any 92 and earlier Chevy P30 owner should have that book.

Dave

wolf_7669 · 10-13-2014, 11:37 AM

Thank you all for your help. The manuals will be especially useful. The previous owner even managed to find his owner's manuals for the appliances and stuff. When I have a change to go thru them, I'll post what I've got to see if there are any to add to the site's library.

After I get her moved to the house, the really fun part starts (going thru everything and finding out what works, what doesn't, what's missing, etc.)

Already know I need a freezer/fridge as it's not there, the rest I'll have to play with.

Any suggestions for the house battery as far as size/capacity I should get for a 31' MH? Should it be a special type, or is a regular lead/acid battery ok to use? The current one has sat discharged for 2 years so I'm pretty sure it's toast just like the engine battery was.

George Schweikle · 10-13-2014, 11:47 AM

Have you checked the battery compartment?. My old '83 Winnebago Chieftain had a slide with one starting battery and two house batteries. You probably already know the starting battery is a regular automotive type, but the coach batteries should be deep cycle at minimum (then there are AGM and other upgrades available).

Quote:

Originally Posted by wolf_7669

...Any suggestions for the house battery as far as size/capacity I should get for a 31' MH? Should it be a special type, or is a regular lead/acid battery ok to use? The current one has sat discharged for 2 years so I'm pretty sure it's toast just like the engine battery was.

wolf_7669 · 10-13-2014, 12:04 PM

Quote:

Originally Posted by George Schweikle

Have you checked the battery compartment?. My old '83 Winnebago Chieftain had a slide with one starting battery and two house batteries. You probably already know the starting battery is a regular automotive type, but the coach batteries should be deep cycle at minimum (then there are AGM and other upgrades available).

I have peeked in the front compartment and I have 2 batteries - the starter batter and the house battery. The house battery looks both taller and wider than a standard car battery, but as of yet I can't tell what kind or capacity it is. The battery label has road grime all over it and that side of the RV has sticker bushes growing all around and under it so I can't crawl under there to take a closer look yet.

Once I get her moved to the house this weekend I'll be able to take a closer look. I just wanted to verify what kind of battery should be used just in case the PO went with something different. There is just the one on it now, but the battery tray on that side is pretty big and looks like it may fit 2 batteries.