I just bought a 2000 4x4 Quad Cab about a month ago. I put about 1100 miles on it, engine started just dying and giving code 1689. I replaced the VP44 IP, LP and filter about 2 weeks ago.

Last week the engine started to stutter occassionaly, like a momentary loss of a cylinder at about 2000 rpm when I climbed a hill. Over the next few days it got worse and now its stuttering at any rpm above 1000 when ever the accellerator is pushed. It idles fine and runs good for the first few minutes but as the engine comes to full operating temp it gets bad!

I had a bad fuel sending unit so I replaced the fuel tank module after pulling it out (bad pickup screens and pretty dirty). I thought maybe I had a blocked fuel line or dirty tank. No change so I installed a pressure gauge after the LP, getting 18 psi idle and 9-10 psi WOT. Thought maybe I was getting air at the quick disconnects but no pressure flutuations occur when it stutters and I see no air passing through a clear test hose.

Not getting any codes coming up either. Would one or more injectors go bad like this over a few days (couple hundred miles) driving? Or is the IP gone south on me again? I'm new to diesel engine troubleshooting so any ideas would be appreciated.

 

well you said you checked the fuel lines...but id start with the cheapest point...a new fuel filter. if that doesnt work, then move to the IP...which is what it sounds like to me.

 

I put in a fresh filter and it didn't change a thing. I was looking in the repair manual again and it has a cautionary note about the fuel line torque at the injector end. It says that "if the fitting is undertorqued, a high pressure leak will occur causing a loss of performance and poor running. If its overtorqued, the connection at the fitting will be deformed, and will also result in a high pressure leak, except that the leak will be inside the head which might cause an injector miss and low power."

This is beginning to sound like the problem. If this is the problem then did I deform the line or the fuel injector connector tube? Any other opinions out there?