Still not getting decent MPG's in my truck and it's only slightly better than the 12MPG I was complaining about a month or so back. It's running pretty good and has almost no smoke. So far I've added a BHAF, new brakes all around (for people with dragging brake on their mind) cleaned the TPS and the auto tranny is shifting good, plenty of air in the tires...
The truck had a set of 370's in it when I got it and "reportly" got 18MPG Highway when a friend borrowed it to move his folks (Katrina victims) but I'm not convinced that was actual. I put the stock injectors back in only to get 12 MPG. Could it be that the stock sticks are the problem since the 370's did ok? They've got 180K on them. If I replace them, what should I put in for maximum fuel efficiency ?

 

Hopefully somebody with more expertise than me will chime in! But, I know POD's can hurt mileage so don't get those. I know the best injector for me for fuel mileage are the Bully Dog injectors. Not sure for your year of truck but when you buy, find out if they haze at idle etc... good signs that the fuel isnt being burned all the way for maximum efficiency. Like I said, hopefully someone with more expertise will chime in

 

Any oversize tires throwing the numbers off??

With 181K miles, the stockers could be in need of repair/rebuild. I had mine done @ about 240K when I switched them out to 370's...now I'm back to fresh stockers @316K. Empty mileage isn't different (much, .5mpg), towing is up about 3mpg.

I would also suspect slipped timing! That brought my mileage down around 3mpg!
Chris

 

Im having the same mileage problems. The only things left to try here are the injectors, the injector pump and the transmission =(
I suspect the injector pump the most. I think its just way out of calibration and the internals are worn.

 

i dont doubt the 18mpg. i get that all the time with my 82 with 370s. got a best of 19.2 with just a 20 mi. round trip driving.

 

I got 300's in mine and get 17MPG and the run great around town!
work well towing too.

 

i would suggest a set of 215s or a small set from ddp up in the great northwest

 

I 2nd the 215 injectors, they give a better spray pattren for improved performance and milage over your stock sticks. Have you checked your timing?

 

Dynomite injectors definatly, I'm pulling 1mpg better on the freeway than stock injectors.
Tim.

 

i have 370's on my truck and travelling from columbus ohio to philly PA i got an average of 16.7 to 16.9, im not sure what my stock sticks ran but if you want a set you could have them

 

I think that the 215s are the way to go also. I have a 175 pump with a 6 plate full forward and have been getting 18.5+ in town lately. I am curious as to what the interstate MPG will be. You may want to take the time to reset the timing while you have the injectors out. If the 370s didnt smoke to much the timing may be advanced a good bit to cover up some of the haze. Then on the other hand it could have slipped if you are only getting 12 MPG but I would think that you would be hazing pretty good once your pump went into full fuel.

 

Thanks all, I really appreciate all the help I've gotten here, both directly and searching the archives. The PO claimed he didn't do "anything else" to the truck but it definitly could have slipped time a bit. To be perfectly honest, I'm a little intimidated by the procedure and a little put off by the initial cost of the tools needed. Any links to or detailed instructions/hints on setting the timing will be greatly appreciated. How much would a good wrench charge to check/adjust the timing? Anyone know a good wrench near B'ham AL?

I've also gotten email saying that I should check the valve lash, which definitley can't hurt anyway but is that a common MPG robbing item?




Fuel4me thanks for the offer and I'd like to take you up on it, check your email

 

To be perfectly honest, I'm a little intimidated by the procedure and a little put off by the initial cost of the tools needed. Any links to or detailed instructions/hints on setting the timing will be greatly appreciated. How much would a good wrench charge to check/adjust the timing? Anyone know a good wrench near B'ham AL?

I've also gotten email saying that I should check the valve lash, which definitley can't hurt anyway but is that a common MPG robbing item?


I am like you, I am fairly mechanically inclined but I am afraid to do my own timing. I live not too far from you over near Tupelo Ms. I am getting my truck timing and valves adjusted this Friday at Tupelo Diesel Svc and will let you know what it cost me when said and done. That ought to be pretty comparable to what it would cost at a reputable shop in Bham.

 

http://www.dodgedieseldatabase.com/p...ction_pump.htm
P7100 Injection Pump

 

Well, given my current tool situation (don't have the timing tools) I've slated a valve lash adjustment for this weekend. How far off of the 0.010 intake or 0.020 exhaust numbers will my truck have to be off for me to exclaim "Eureka! that was it!!!" (actually I would yell something a bit different but as this is a family board...)

also anyone know why John Faughn's P7100 link below doesn't work for me? I end up at http://www.cumminsdatabase.com/
I end up there when I follow a lot of other links in the archives too, but not all of them. Some work just fine.

And on a lighter note, anyone know why "The Road Warrior" (Mad Max) movie was shown on the History channel yesterday? Didn't know that was based on fact...