Fuel Economy on Information Center way off

[More Power]

Personally, I'd work to solve the codes first, then worry about fuel economy/DIC. Like you, I'd leave the injectors for another time.

Jim

[JohnC]

The DIC calculates mileage based on miles traveled and fuel scheduled by the ECM. If the injectors are delivering fuel at a different rate than normal (I think the balance rate is an indicator of this) then the calculations will be off.

Like Jim said, get the codes fixed first, but, next time you fill up zero the fuel used counter and see if it agrees with your subsequent fill up or not. If it's off the mileage calculation will be off too.

[Steveesp52]

I'm going to go after the EGR codes and when I'm there, I'll check out the turbo for the P2563 code. I'm still thinking it all has something to do with carbon buildup and am hoping it doesn't cost a bunch of cash to get it cleaned up and back on the road with no codes.

The DIC gallons used has always been off which was causing the MPG average to be off about 2 mpg. Most of the time, I'd pump 26-27 gallons in when the DIC would tell me I used 23-24 so maybe the injectors could definently have had something to do with it all along.

My wonder is what are others seeing with the DIC calculations gallons used and average MPG with old vs new injectors?

[DmaxMaverick]

Are you using any electronic power modification? If so, they will cause the actual/DIC mileage to disagree.

[Steveesp52]

Truck is totally stock.
I don't think it has been its entire life though. There is an EGT sensor bung in the down pipe from the turbo. I know the ECM had been recalibrated to Stock prior to purchasing the truck. The previous owner was chasing a surge from around 80K until they traded it at 138K. They were driving the truck about 10K a month. Figured from the build date to when they traded it. Unfortunately the dealers they were using never picked up on the fuel pressure sensor as being the cause of the problem. I'm sure if they were able to get the truck fixed, they would have put many more miles on it.

I didn't have a chance to get to the truck this weekend and at the moment, it really is a back burner project since it still runs and I now have a spare car back on the road.

I'll keep you all posted on this one if I can ever get time to work on it.

[rat4go]

My DIC has consistantly been HIGH by about 5% (example...it reads 20 mpg when the math says I got 19mpg) for the entire time I've had my 2003. My friend's DOGED (oops, did I mix up some letters??) is about 10% high!!

The best explanation I've been given is that the DIC uses 'fuel scheduled' (like mentioned earlier in this post) and was 'calibrated' using different (better?) fuel than is typically available in the real world, so the 'scheduled fuel' is not the same as the 'real' amount delivered (it's less than 'real') thus the error in mpg.

[madmatt]

put your truck info in your sig to help us help you!!