Just had my injector and lift pump replaced and was told by my cummins guy today that there is a sneky way too figure out whether your pumps are weak without a fp guage.

He said that you hand calculate your mileage over 3 tanks and average....then add your edge EZ or comp un pierced. Do the same thing and as long as your driving styles are the same, your mileage should not drop more than 1 mpg. Infact it should rise but nothing perfect.

So if your mileage drops more than 1 mpg, than chances are your pumps are getting weak.

Not sure how true this is...but you never know!!

Jon.

 

Go through all that trouble? Why? How about checking with a hand held FP gauge or by installing an in cab fuel pressure gauge?

 

My thoughts exactly. A gauge is just simpler and more immediate.

Justin

 

Also...you could do a lot of damage to your IP in just 1 tank of fuel if your LP is bad but goes undetected till next fill up....at which time you'd need a gauge to confirm, anyway!

RJ

 

I think the dealer is just pulling your leg so you don't get a gauge and then he replaces the pump again. Your mileage will vary by 1-3 mpg based simply on the time of year, driving habits, road conditions, fuel blend, brand of fuel, bio-diesel, temperature, humidity, ect, ect, ect.

This is about the dumbest thing I have heard a dealer say.