Is my injection pump failing?

[jdmetcalf57]

I have a scan gage on my truck which I have calibrated. In the past it has been very accurate on mpg for each tank of fuel. On my recent return trip from Colorado it consistantly said I was getting worse mileage than what a fillup and calculating it gave. In other words the scan gage is thinking it is injecting more fuel per injection than it really is. My IP has about 60K miles on it and the 120K warranty is about up.

To me this could be an early sign of wear since according to my scan gage it is not pumping as much fuel per injection at the same throttle setting that it used to.

What does anyone think? Is there a test you can do to check for wear or otherwise check the health of the IP? I would like to know before my warranty is up.

[Hubert]

How does the scan gage work and measure fuel consumption?

No way to tell on a truck the exact health of an IP. The usual scenerio is take it to a pump shop and they bench test it with special equipment. Then I imagine its looked into for specifications. I am for sure no IP specialist but read many times before the DS pumps are fairly tough mechanically and last a long time especially the newer ones. And when they die they generally set codes and act up a somewhat slow death. I doubt yours is bad in 60K miles unless some bad fuel aged it prematurely. Always suspect fuel quality and delivery first ie check Lift pump and filter etc.

Maybe your injectors are old not the pump??? Suggested replacement is
80-120K miles. Maybe nothing is wrong? I am unsure from post did milage actually change?

[JohnC]

Change your fuel filter and check your lift pump.

[jdmetcalf57]

The scan gage uses info from the truck computer. I think it just figures fuel mileage based on speed and what the computer thinks it pumping for fuel. It does have the ability to calibrate it based on actual fuel usage which I have done.

About how many miles does it take from acting up untill it dies? I often drive it 1-2Kmiles from home and really don't ever want to have to change a pump out on the road.