I have an '89 E350 with a 460 in a cut-away chasis. Problem is that when towing, or loaded, the engine will start to missfire and lose all power. As it missfires there is little if any power, so I have to pull over right away. Sometimes the engine temp will rise, not always though. It almost seems like it running REAL lean. No fuel smell from engine. I can still hear the fuel pump running. I thought it might be vapor locking (although with an electric pump I doubt it) so I wraped the lines from the frame mounted pump to the end of the fuel rail. After the truck cools it will run fine. Also I can make the same trip at night and there will be no problems. So it seems as though the ambient temp must be high and the truck must be under a load. I am unsure if there is an in-tank pump as I am new to this truck...but if so is there a way that pump cant keep up with fuel demand and locks up, or would the HUGE frame mounted pump still pull from the tank? This condition can happen at any fuel level. It is also VERY intermittant...probably only happened 10 times in 2 years, but it always happens at the WRONG time (I hate Murphey and his stupid law).

We use this van to haul our race car and sitting on the side of the road on 100+ temps waiting for it to cool down SUX!

Thanks much

 

Change the fuel filter first, before you screw with anything else. The fuel system is set up to recycle fuel (has a return line to the tank from the engine) so you shouldn't ever have vapor lock.

 

Yeah...That was the first thing I did...I am REAL lazy, so I take the easy route all the time.

Thanks though,

Rem

 

Well-the same thing happened to me 2 days ago-but it was 113 degrees outside (I live in the desert). My 92 e350 class c m/h with a 460 almost sputtered to a stop after a long hot drive. Slapped my Snap on scanner on it - no codes. Hour later no problem. Today no problem. Heres my suspect--overheated Ignition Control Module. Ford does have a problem with these modules and so does aftermarket and they are heat sensitive which is why they want it coated with heatsink material before mounting. There is no way to check it out unless you catch it in the act, so I'm gonna stick one in the glove box and swap it in real fast if I have a prob again. They aren't all that expensive and i know they do fail so won't hurt to have one handy, anyway. As i recall they mount on the drivers fender well and have just one connector, so easy in and out. Good luck with yours and let us know what happens.
Alex

 

Do you have dual tanks and if so does it do it on both tanks? My thought is what you are hearing is the high presure pump, but maybe the in-tank pumps aren't working or are weak. My 86 F250 4x4 with a carb gave me fits, I finally modified the complete fuel system. If I had a dollar for every Ford Truck I have seen or worked on with fuel problems my location would be on the beach in the Bahama's.
P.S. I worked for a Ford Dealer in the 80s.

 

I only have 1 HUGE tank on the truck. It feels like a fuel thing to me, but the truck is so huge it is hard to get a feel for what is really going on.

Thanks

 

There is usually a filter screen on the fuel pickup in the tank. If you have crap floating around in there that could stop fuel flow. Also the fuel pump(s) are sometimes powered off a terminal on the altenator (so the pump only runs when the engine is) and as it gets hot you could loose power to run the pump. These are just things that came to we while thinking about this.

 

Did you find the fix? I have exactly the same issue with a shuttle bus. I've replaced the coil, plugs, ICM, Distributor pickup coil. Still does this when hot. It's something electric

 

19 year old thread, I doubt he will be back
Maybe start a new thread
Check your fuel pressure
Check it for codes