Could Really Use Some Help!!

[shinetimedetail]

I have a 1995 E350 with 135K I bought this van about 3 months ago with 123K. When I bought it it seemed to run pretty well. I tow a 12x6 enclosed trailer with maybe 2K in it. I prob have 3500 lbs total weight with trailer and stuff inside van.

About 3 weeks ago I had some problems when I got done working. In the morning when I went to my job the van was running good. 8 hours later it had a noticeable loss of power and it seemed like it was running on its last leg. I was changing high ways and I got on and hit about 70 mph. Right when I hit 70 the motor just completely lost power and I couldn't accelerate any more. I pulled over to the shoulder and right before I stopped the motor died. (It felt like I ran out of fuel) The van started right back up and ran fine.

About an hour later I went to drive it again and it was running rough again. So I've put like 1000 miles on it has run 'somewhat' ok. When the trailer isn't on it runs pretty good and I get about 18-20 mpg. With the trailer at 3500 lbs I get about 11 mpg. Is this average? I bought the van with the hopes of getting about 15 mpg. Anyways tonight it is running pretty bad and it feels like its going to just crap out on me any minute. Also I was going up a hill and it just didn't want to seem to upshift. I was prob at like 3K and I even tried letting off the gas a little. I had to completely let of the gas and it then shifted.

Any help or pointers would be great. I changed the oil about 4K ago and I used penzoil bc I was in FL and it needed to be changed. I also changed the fuel filter about 9K ago and cleaned the FPR screen.

Thanks for any help

[White95f250]

Did you use any type of oil additive? Check your fuel pressure and all the wiring. Sometimes things like to become loose on these. Do you have access to any type of scan tool? Is there any excessive smoke or different color smoke coming out?

Just a few simple questions to get this going.

[shinetimedetail]

No I didn't put an additive in-what can I use? What wires should i be checking and where is the valve to check the fuel on a van. I don't have a scan tool but when it lost complete power on the highway that day a cel light came on but autozone said there were no codes stored. No smoke except when cold in mornings.