I'm a couple days into a 4200 mile trip and my 1991 Tioga Arrow motorhome (Ford E350-based with 7.5L 460i engine) is giving me some problems. I'll be driving along and it will start to lack power but only for fractions of a second at first. It will get progressively worse until the engine dies, even if I immediately pull over and put it in park. It will then refuse to start. The engine will turn over but it acts like it doesn't have any fuel/spark/something. After 10-60 minutes, I can start it back up immediately (like normal) and drive for 4-160 miles before it repeats. A mechanic replaced the fuel pump and fuel filter and it drove fine for 160 miles... but then it had been sitting for a couple hours so it might have driven fine regardless of the pump/filter. A couple times when the engine died, it threw a CEL. I tried scanning it at AutoZone but their scanner never was able to pull any codes. The CEL went out whenever it was ready for me to start driving again. Any idea what this could be or what I could try next? Thanks!

Vapor Lock? Fuel gets too hot and vaprizes...A common failure mode on many older big blocks.

In tank fuel pump. Gets hot and quits working. Fuel pressure drops, engine quits. Pump cools off, and works again.

So are there two fuel pumps on this model? I had asked for the in-tank fuel pump when I bought the part at AutoZone but the only thing they had appeared to be an inline model and that is what the mechanic installed for me. Any idea where I would be able to pick up the in-tank pump?

rjxj wrote:MaybeX2- a common problem on that era Ford.

Intermittently Dies | Good Sam Community

azrving
Explorer
Sep 04, 2017
Maybe
sch911
Explorer
Sep 04, 2017
Vapor Lock? Fuel gets too hot and vaprizes...

A common failure mode on many older big blocks.
DownTheAvenue
Explorer
Sep 04, 2017
In tank fuel pump. Gets hot and quits working. Fuel pressure drops, engine quits. Pump cools off, and works again.
MattR
Explorer
Sep 04, 2017
So are there two fuel pumps on this model? I had asked for the in-tank fuel pump when I bought the part at AutoZone but the only thing they had appeared to be an inline model and that is what the mechanic installed for me. Any idea where I would be able to pick up the in-tank pump?
F1bNorm
Explorer
Sep 04, 2017
rjxj wrote:
Maybe

X2- a common problem on that era Ford.
garyhaupt
Explorer
Sep 04, 2017
I'm with the fuel pump crowd. Any parts store will have the pump..or should have...the problem is going to be dropping that tank. If you are going to do it yoursef, you need to get the fuel out. Might as well just drive the bugger till it's dry. Make your last miles the one to the fixing location.

If you are having a shop do it? Same thought applies...drive it ill you are dry. They'll charge you to drain and so on.

I see you were or are still, in Wa. See if a local Les Shwab can do it. That way you have service everywhere in the west.

Gary Haupt
K_Charles
Explorer
Sep 04, 2017
rjxj wrote:
Maybe

I too would try the ignition module first. A common problem and a cheep thing to try.
j-d
Explorer II
Sep 05, 2017
Please confirm the FORD year model of your Chassis. A "1991 Tioga" could well be on a 1990 Ford Chassis, and I'd like to look up some parts.

I think that in the late 1980's - early 1990's, they used two pumps. A low pressure in-tank pump fed a high pressure chassis-mounted pump.
MattR
Explorer
Sep 05, 2017
Thank you everyone for your input! I'm waiting at an RV service center until they open tomorrow and then hope they will be able to replace the in-tank pump and the ignition control module. Both are supposedly in stock a few blocks away at Oreilly's.

Per the door jam, it was manufactured by Ford 2/1991 and modified by Fleetwood 4/1991. If you need anything else, just let me know!

Thanks!
MattR
Explorer
Sep 05, 2017
Well the RV service center said they were a few weeks out so they couldn't work on my motorhome but I picked up the parts at O'Reilly's and I found another shop that could do it this morning. Hopefully in a couple hours with the in-tank fuel pump and ignition control module replaced everything will be back to normal and we'll be on the road.