Engine/Transmission (1994 - 1998) 1997 dodge 12v hard on fuel.

[SRay]

The last few months I have notice my mileage being lower than usual. I have service records, and every tank of fuel recorded and automatically added up on my iPhone app (best app I ever purchased for my phone). It's showing a decline in mileage from what I usually averaged 18 mpg. Sometimes I easily get 21 mpg. Now the app is showing that mileage is down to 13-15 mpg.



I've been told that since I get fuel from the same source for the past 4 years, likely watered down fuel. Was told to try using stanadyne fuel additive to see if it improves. Now I'm noticing the mpgs coming back up but not at the normal level yet (still using same fuel plus stanadyne).



I had injectors pulled and pop tested to be sure they're not weak. Each injector fired very close to each other in pressure at just 260 bar which it says right on the body. All 5 holes fired perfectly on each injector and they're like new even with nearly 500,000 k's (312,000 miles). The 180 hp p-pump is still original and I was told by pump shop it's running good. (smooth idle, smooth snap tests, etc)



I don't have a pyro installed yet but last time I checked the boost pressure, it was at 40 psi max power.



Could other stuff be worn out? I had my valves adjusted to . 008" and . 018" according to TDR sites last week.



It's hard to make money when everything is ***** nowadays costing more $$

 

[Cosmo]

40psi on a stock turbo? Stock head bolts?

From what I've read, beyond 35 psi you're losing efficiency.

Having said that, I'm right there with you at ~40psi. I'd like to drop mine a couple of ticks.

Oh, and my daily commute is about 20 minutes - a couple of miles of 25-35 mph, then a few miles of 50 mph with stop lights, then a couple of minutes of 30 mph. I'm averaging about 15mpg hand calculated, and that's with a 2wd and 285 tires.

I've got some tweaking to do, I just lack the drive to do it.

 

[Mikey-KE7LBB]

I'd suggest an upgrade (or replacement) of the injectors that you already have...



Just based on the fact that they 'pop' at the desired pressures doesn't necessarily mean that they are spraying/atomizing the fuel correctly...



40PSI is a gamble with fate IMHO, but the cards and stars may all align with you!!!



Proud owner of an '09 4x4 QC that is afraid of 30+PSI and driving it like I paid for it as opposed to the bank still may be buying my abused junk!!



The '92 however, gets ALL the abuse and 'hotrodding' that I can throw at it and it still keeps on going!! 329K+ miles and counting!!



GOD bless the MECHANICAL Cummins! And may HE keep them on the road FOREVER!!! AMEN!!!

 

[budnate]

I run a seafoam through mine a couple cans in a full tank when I make a freeway run I do it a few times a year I do 80% of in town running around with my truck when using it, it definitely runs and idles better after getting some of the sauce run through it and smokes less at start up from a cold start, keeps the rings clean and not gummed up.

 

[SRay]

Cosmo: I do a lot of heavy hauling, driving the truck everywhere for pleasure and the boost rarely go that high unless I'm drag racing, dyno days, sled pulling or just bored on some days. Usually when boost is that high, efficiency does go out the window even though power is good.



I always try and maintain a controlled foot on the throttle unless someone wants to be an ***** driving around me, they get the soot.



Likely some day the head gasket will blow, only time will tell. Engine has been at that power for almost 4 years now.



Mikey: Larger injectors are on my list of things to get, but as I'm still running a stock clutch with about 1,000 tq at the wheels, I don't want to add more power yet. But, I could use them if I keep my foot out of it.



View attachment 81462



My last clutch from spring 2011, called it quits.



Yes, Bless the MECHANICAL Cummins! Best Engine, pump and truck I've ever owned.



Budnate: Hmm, I had forgotten about Seafoam as I haven't used one in a couple years. I'll give one a try.

 

[Dutch & Di]

Have you tried just changing the air filter? We were traveling east in March and suddenly lost a good amount on our fuel mileage. Pulled into Wal*Mart, bought a new filter, installed it and the mileage started coming back up. Worth a check anyway. Di

 

[SRay]

The filter minder hasn't moved yet since ripping the foam secondary filter off

 

[HCannon]

Brakes dragging? I had a problem of the brakes not releasing all the way and the mileage got bad. It wasnt all that noticeable.

 

[Missouri Mule]

Unless they changed or someone came up with different valve clearance specs my factory servce manual states . 010 (intake) and . 020(exhaust).

 

[AEdelheit]

The filter minder hasn't moved yet since ripping the foam secondary filter off

I wouldn't trust those filter minders, dodge uses pretty cheap ones that don't allways work

 

[SRay]

Hcannon: the brakes have been servced with new pads and bushings. The front had been dragging pretty good before that the new pad I had on lasted only 2 weeks. After noticing large amount of brake dusts on the wheel, I noticed bushings were shot. So all fixed and moving freely now.

Missouri mule: I know the service manual says . 010 and . 020. The Tdr site said that we can get away with the . 008 and . 018

AEDelheit: no they don't always work. But filter is visibly good.

 

[yenga80]

SRay what is the app called that you figure your fuel milage? I'm interested in getting it also.

 

[SRay]

Yenga80: it's called Road Trip mpg, mileage and fuel economy. I love that app. Been using it for 3 years now

 

[yenga80]

Thanks! I'll check it out

 

[Mikey-KE7LBB]

SRay what is the app called that you figure your fuel milage? I'm interested in getting it also.

It's called "calculator" lol!!! Gallons/miles driven=MPG!!!

FYI... This particular App comes with EVERY phone!!!

 

[SRay]

Mikey: yes we can use the calculator, but this does everything else including service records, cost of service, expenses, fuel use, reminders, insurance, truck payments, etc. it takes it all together and adds it up.

Every number we put in is automatically done. Mine tells me that my truck cost 50¢/kilometer when everything calculated in. So I should be charging more than 80¢/k in order to make a profit for example.

I also do this on my buddies fords and Chevys and it tells me that my dodge is cheaper to own and operate over a period of time.

Best tool I've ever had.

 

[mwilson]

Mikey: yes we can use the calculator, but this does everything else including service records, cost of service, expenses, fuel use, reminders, insurance, truck payments, etc. it takes it all together and adds it up.



Every number we put in is automatically done. Mine tells me that my truck cost 50¢/kilometer when everything calculated in. So I should be charging more than 80¢/k in order to make a profit for example.



I also do this on my buddies fords and Chevys and it tells me that my dodge is cheaper to own and operate over a period of time.



Best tool I've ever had.

You would have disappointed if someone hadn't busted your stones over it...



I will have a look at the app tonight myself, sounds interesting.



Mike.

 

[SRay]

I think there are apps for other phones and this is for iPhones

Mwilson: very funny, hope you like the app too

 

[DRAG DIESEL]

I had a similar problem. After trouble shooting everything over many years. I found the fuel stop with the cheapest fuel was "fixing" their pumps (not as much fuel coming out of the nozzle as it counted on the display). went across the street payed 3 cents more per gallon and the milage came right back up instantly.

 

[JesseGray]

I am not familiar with the product SeaFoam, can one of you guys give me a source to purchase the product?



I am having basically the same problem as SRay, and where the EGTs were right around 900 to 1000, they have risen to 1150 to 1200 on a 26 mile 6% grade.

I am getting roughly 12mpg pulling a 13k fifth wheel. Two different tire sizes on the truck make the mpg a rough estimate---but I keep good fuel and maintenance records.



J Gray