Exactly right. Sounds fuel related. If it runs better when you back off the throttle it is running lean. Live feed scanner and watch the O2 sensor readings. Fuel relay bad, wiring breaking down not allowing enough amperage to the pump? A voltmeter attached to the plug at the pump and run into the cab so you can watch to see if voltage drops under load. If it drops under 11 volts you have a voltage/amperage supply issue. Mikey
Anson, Bob, Mark, Mike,Joe and Bill, all duly noted, will be asking these questions today when I get over to the repair shop. thank you all for taking the time to offer any thoughts and possible fix, Bruce
