1987 Class A P30 Chevy 454 fuel pump/filter

[mandobud16]

I recently acquired a 1987 Executive Diplomat 35' motorhome with a Chevy 454 (about 30,000 miles) on a P37 Chassis. We took it out just over a month ago for about 200 miles and it was great. I took it out again last weekend and it started hesitating upon acceleration about 15 miles into the trip. Eventually it stalled. It would start and idle, but any load or acceleration applied to it would stall out. I've started the diagnosis process.

I performed a test today. Ran the motorhome on both auxiliary and main fuel tanks. The motor seemed to be fine when running on the auxiliary tank, but stalled out after a few minutes of revving off of the main tank. Can I conclude that the problem lies with the main fuel pump/filter?

I found the filters. There are two inline filters on near the back axle on the passenger side. I'll be changing those. I found 2 electrical devices that could be the main fuel pump. Can you help me identify which is the main fuel pump? the larger cylinder of the two, has a line in and line out, with two electrical terminal boots on the bottom (power/ground). The smaller cylinder, has four or six hoses connected to it (maybe fuel return hoses too)? It also has power/ground wires. What is this? Anyway, as always any help is appreciated here. Thanks!

[jolooote]

Google Chevrolet P30 chassis manual,

[blazenpm]

I have a 1989 P30 Bounder. It also had a fuel uptake problem. I replaced the engine fuel pump, the uptake fuel pump in the fuel tank and the fuel regulator outside the tank, and the 3 fuel filters, as well as the filter on the carbutor, and I had the carbutor rebuilt. Boy does it run great! I know that sounds like a lot. It could be as simple as a crack in the fuel line, after all we do have old rigs. That just about covers it, oh, wait, I had a total service of the generator. All of this falls back to OLD gas sitting in the tank causing a lot problems down the line. Remember, when you put your rig in storage to put Fuel stabilizer in the tank, this will help to extend the life of your gas. I would like to talk, as we do have many like things on our rig.

[SCVJeff]

Boy does that bring back memories... my 85' Pace did the same thing. I changed filters, rebuilt the carb, new vacuum lines, with no fix and finally gave it to the shop and told them don't call till they figure it out. WEEKS later they called and found a crack in a brass hose barb to 1/2" Female thread adapter screwed into a 1/2" pipe heading to the engine. This one was flex to rigid from the tank. That hairline crack was almost invisible but was sucking air. Look carefully at those adapters on all sides carefully

[rvten]

Check the carb for a filter also. My 87 had one. Only had a single tank so only one filter in frame..

[Son_of_Norway]

The one with the multiple hoses might be the switching mechanism for the two tanks. Do you have a switch on the dash? See if switching it results in current at the mechanism. Hopefully the new filters will solve your stalling problem.

Miles