97 F-150 Engine Runs ROUGH at 1500 RPM

[jpartak]

97 F-150 4.2L V6 2WD Manual (Yep, I'm the guy that bought THAT truck). Anyways... I just installed a rebuilt motor, new EGR Valve, EGR Pressure Sensor, Plugs, Wires, and Bank 1 Cat. I am having a real rough run when it is at steady throttle at 1500 RPM but seems to idle well and runs good under load.

The EGR pressure sensor tested bad, and when replaced seemed to dramatically improve the overall engine feel, but still have that "sweet" spot at 1500 rpm.

Exhaust pipe seems to be highly carboned (ie rich fuel). Any ideas on the next place to look.

[Skudly]

Originally Posted by jpartak

97 F-150 4.2L V6 2WD Manual (Yep, I'm the guy that bought THAT truck). Anyways... I just installed a rebuilt motor, new EGR Valve, EGR Pressure Sensor, Plugs, Wires, and Bank 1 Cat. I am having a real rough run when it is at steady throttle at 1500 RPM but seems to idle well and runs good under load.

The EGR pressure sensor tested bad, and when replaced seemed to dramatically improve the overall engine feel, but still have that "sweet" spot at 1500 rpm.

Exhaust pipe seems to be highly carboned (ie rich fuel). Any ideas on the next place to look.

Hello,
My next question to you would be if the MIL light has come on or not?

[kenwood guy]

what was wrong with the OG motor???

[jpartak]

Originally Posted by Skudly

Hello,
My next question to you would be if the MIL light has come on or not?

Only one MIL for "Catalyst effiency below threshold". I've got a know exhaust leak on bank one which I've got the parts on order for.

Is this related?

[jpartak]

Originally Posted by Skudly

Hello,
My next question to you would be if the MIL light has come on or not?

Only one MIL for "Catalyst effiency below threshold". I've got a know exhaust leak on bank one which I've got the parts on order for.

Is this related?

[jpartak]

Originally Posted by kenwood guy

what was wrong with the OG motor???

It's easier to answer what was RIGHT on the old motor. Seriously, though, blew an intake gasket at 203K miles and the motor was in general very tired. So between dumping gallons of antifreeze weekly, burning oil, major spark knock, and at least 12 MIL codes, it was time to replace.