1998 7.3 liter major hesitation

[pacamada]

Guys please help! I have a 1998 E350 box van with a 7.3 liter. On cold mornings (below 40) the truck has absolutely no power. You cannot get the truck over 30 mph. On the highway it runs fine. Sometimes I can put it in neutral and rev it and it runs fine but it is steadily getting worse. I put all new filters in it. It stays plugged in and has fuel additive in it. It never seems to heat up either. Any help on this would be greatly appreciated.

[Jeff_Northon]

What engine oil are you using and how many miles on the oil?

[pacamada]

Not sure what kind of engine oil. My employee changed it and put the recommended oil in it. The oil was changed less than 1,000 miles ago. Thanks.

[viper5]

If this goes away after the truck warms up you may want to check into the exhaust back pressure valve and sensor

[Jeff_Northon]

You can disable the exhaust back pressure valve by unpluging the electrical component. It is under and behind the turbo. The connector should be on the right side of the engine about nine inches from the exhaust back pressure valve. I would bet that it is sticking in the closed position.