I need help. I have a strange situation even Ford can not figure out. I have an RV sitting on a Ford E350 frontend. It has developed an intermittent problem with continuing to run after it has run many miles and hours. I drove this from NC to Kentucky back in June 2008 with no problems.

Two weeks later, I drive it 180 miles to the mountains. It cuts off just about a mile from my destination. I have trouble getting it to start. When it does start it is running very rough as if it is not getting fuel. I finally get it running again and it gets to the camp site. I figure I have water in the gas. I put in STP gas treatment with about 20 gallons of gas thinking it will fix the problem. I drive it home about 160 miles and pull in to a gas station,(different one from my last fill up) it cuts off again, same deal, runs rough won't idle properly. I finally get it on the road and home.

Two weeks later, I drive it 230 miles to SC and 160 miles back toward home, no problem until I pull in a rest area and it dies. Hard to start, runs OK if I rev the engine, and that is the only way I can get on the road. At 65-70 MPH it runs OK. It dies about 17 times in the next 65 miles. Each time takes a while to get it started and I have to rev the engine to keep it going at lights. When it is running it backfires and sounds and feels like it is firing out of sequence, as if wires on an old distributor are out of firing order.

At one point I called a wrecker while one block from my Ford dealer cause it would not start. I finally get it started and to the dealer after closing. They have it 2 days and can not find anything wrong with it. They drive it 60-70 miles and heat it up, no problems indicated, no codes given. They indicate the thormostat may need to be changed because temp is no higher than 160 degrees, but don't think that is the cause. They also think maybe the fuel pump could be the problem. The fuel pump did, or perhaps still has, a whining sound to it. My mechanic nephew indicated the fuel pump may be getting ready to go before I ever had this problem. They also suggested the IAC (Idle Air Control). None of this is guaranteed to fix the problem to the tune of $1335. My bother in law thought it might be the crankshaft sensor since he had one go bad with similar symptoms.

I need some good advice on what direction to take. I hate to spend a lot of money on something that may not even work. Please help!!!!