We started full timing yesterday in our 1985 Travel Queen. She ran great for 685 miles. We traveled from Northern California to Kingman AZ. After I fueled up in Kingman she started have some loss of power during acceleration. It progressively got worse to the point of only doing 15mph on the incline. When pressing on the gas petal it acted as if it was running out of gas, no power. I pulled off on an exit and consulted my mechanic back in CA who is most familiar with it and he had me check the distributor, to see if it had loosened up. It was fine. He had replaced all fuel filters. He mentioned fuel pump and/or possible vapor lock. This took about 30 minutes with the engine off and so when I started it run ok still not much power but still not great. I found a pattern in that if I let it sit and cool then I could drive for a while before I lost almost all power again. I limped it Prescott and on the small hill in town where we were headed for the night she lost all power completely. It died on the hill. I could not get it started. I shut it off and was calling assistance, so I was on the phone for a bit. Got done and tried starting it again and she stated reluctantly. I put her in drive and made it the RV park. Now I just need a good mechanic. The engine was running fine as far as oil pressure and temperature. She starts right up, at least up until I couldn't make it up the last hill. I think fuel pump but not sure. It has a Chevy 454 7.4L engine. I don't think it is altitude but then I have never driven an RV through the higher elevations for a long period of time. Any suggestions?

You said it happened after you got fuel. Could it be bad fuel?

I thought that also, but I not sure why letting the engine cool down would make a difference. I am going to get some octane boost tomorrow regardless.

I just drove that route last week, 6800 feet at some places to get to flagstaff, and some good hills to go down as well, we were down to 35-45 on some of the passes pulling our 38 foot fifth wheel and towing a car behind the fifth wheel, but back to your problem, it does sound like either vapor lock or fuel pump, sending prayers your way for a quick solution to your problem

Had the exact same problem with my old 454. Once it was the fuel pump in the tank but then I COULD TELL BECAUSE IT WAS NOT RUNNING. aLL THE OTHER TIMES, (ABOUT ONCE EVERY THREE YEARS) IT WAS ALWAYS THE ROTOR, CAP AND

I would suspect that the fuel filter is clogged (even if it was just changed). If not the filter, the fuel pump.

I need a good mechanic in Prescott AZ. | Good Sam Community

gemert
Explorer
Mar 19, 2014
You said it happened after you got fuel. Could it be bad fuel?
learningacrossa
Explorer
Mar 19, 2014
I thought that also, but I not sure why letting the engine cool down would make a difference. I am going to get some octane boost tomorrow regardless.
wirenutz
Explorer
Mar 19, 2014
I just drove that route last week, 6800 feet at some places to get to flagstaff, and some good hills to go down as well, we were down to 35-45 on some of the passes pulling our 38 foot fifth wheel and towing a car behind the fifth wheel, but back to your problem, it does sound like either vapor lock or fuel pump, sending prayers your way for a quick solution to your problem
jwyoming
Explorer
Mar 19, 2014
Had the exact same problem with my old 454. Once it was the fuel pump in the tank but then I COULD TELL BECAUSE IT WAS NOT RUNNING. aLL THE OTHER TIMES, (ABOUT ONCE EVERY THREE YEARS) IT WAS ALWAYS THE ROTOR, CAP AND
TucsonJim
Explorer II
Mar 19, 2014
I would suspect that the fuel filter is clogged (even if it was just changed). If not the filter, the fuel pump.
Executive45
Explorer III
Mar 19, 2014
Well, it sure sux to start your adventure like that....There's not much in Prescott, Affinity RV is there but I haven't heard good things about them. I'd check in the office and see if there's a good auto mechanic in town. It's a gas engine so checking it out should be pretty easy. Now a few questions:
1. Do you have a mechanical or electric fuel pump?
2. Do you have a water separator installed?
3. Where is your fuel filter? Is it the small in line one in your fuel line? or the one inside the fuel bowl? If it's the inline can you see any fuel in it?
4. Can you follow your fuel line down from the carb and tell us how close it is to the exhaust headers?

If it's a dirty fuel filter that's a simple fix. There's a NAPA in town that should be able to get you the correct one. That's a DIY.
If the fuel line is too close to the header/exhaust you could be suffering from vapor lock. Again, a simple DIY fix. Get some muffler wrap from NAPA and wrap the fuel line.
If you have a water separator, make sure there's no water in it.
Lastly, if you have an electric fuel pump, you should be able to hear it click when you turn on the key. They're easy to change out too. If it's a mechanical one, they're pretty easy to change out but more work. Easier to get to from underneath. Good luck and update us on your progress.....Dennis
Seneca_35GS
Explorer
Mar 19, 2014
Does it have a catalyic converter? A bad catalyic converter makes a engine run like crap.
Paul_G_
Explorer
Mar 19, 2014
From past experience, I would guess the fuel filter. A plugged fuel filter will show those exact symptoms. By the way, you have two fuel filters, one along the frame rail (usually right side) and one in the carburetor. Again from past experience, it's usually the one on the frame rail that plugs first. On our first motorhome, I carried two or three as it had rusty tanks until we replaced them.

Paul...
moisheh
Explorer
Mar 19, 2014
Classic signs of vapour lock. Next time it quits pour some water on the fuel line in the engine compartment. If it fires up right away it was vapor lock. A bad in tank fuel pump can also have similar symptoms. Does an 85 have an engine mounted mechanicalfuel pump?

Moisheh
WA7NDD
Explorer
Mar 19, 2014
Had the same problem on different motor Ford 460 Van, just as I switched tanks going down the road it just ran out of fuel. Blowing into the gas tank did not help but some gas came out the fill hole. I got a cup collected gas by blowing into the tank then pouring the gas into the carburetor. It started drove a few hundred feet and quit. I did this about three time to get to an off ramp where there was a Quick Stop with gas. I called a tow truck outfit the guy showed up and rammed a screw driver through the fuel filter. It started right up and I drove it on into Salt Lake and back home to Idaho, then change the filter.