Mpg's in a 94 - Diesel Forum

tylerprochaska · 03-08-2006, 09:34 PM

I have a customer that came to me today and wants to get a few more mpg's out of his 94.
Its a 1 ton crewcab dually stick, Hes in his sixtys, doesnt care about more power just wants 2 or three more out of it
He said it s only getting 9 to 10 mpg, stock truck,

Hes ben getting alot of bad info on how to do it,

My thoughts are changing the exhaust to 3 inch maybe a better air cleaner, but what Im wondering is would a tuner or chip be worth the money for this year?
I know what they do for 99 and up(mostly what i work on and drive) just dont know if it would help on the mech pump truck..
just looking for input on people who have done mods like this and what would work best for this situation.. Dont want to throw money where it wont do the most good!
Thanks for any help in advance..

Soaggydogg · 03-08-2006, 11:30 PM

He won't recover the money spent on mods for the increase in mpg.

Complete exhaust 3" dp and 4" exhaust no kitty.
Gut the EBPV.
Tymar intake.
Clean the Fuel Pressure Regulator screen and replace the fuel filter.

Is that 10mpg towing or empty?

Chip will give more power but not mileage unless driven that way.

Patrick Feeley · 03-09-2006, 12:01 AM

Something is wrong with his truck (assuming he has a PSD and not a flavor of IDI) as I routinely get about 16 mpg in stock form with 4.10 gears running solo. I'd maybe go with a TYMAR intake, definitely a downpipe, and maybe a chip (possibly a custom tune on that). Check the fuel pressure to make sure it's not over 70-75 psi at idle. Cheers!

johndeerebones · 03-09-2006, 12:41 AM

[ QUOTE ]
Something is wrong with his truck (assuming he has a PSD and not a flavor of IDI) as I routinely get about 16 mpg in stock form with 4.10 gears running solo. I'd maybe go with a TYMAR intake, definitely a downpipe, and maybe a chip (possibly a custom tune on that). Check the fuel pressure to make sure it's not over 70-75 psi at idle. Cheers!

[/ QUOTE ]

Exactly what I was thinking..
Stock truck, 60+ should equal better mileage than most of us see.
Only non truck issue I can see is if he idles long times at startup or sits in traffic alot. May check out his map sensor and make sure fuel system is up to snuff. If its an auto, he could have a trans problem too.

Soaggydogg · 03-09-2006, 07:44 AM

94 PSD was only stick no auto trans.

**Dale I** · 03-09-2006, 02:31 PM

If it's a PSD there is definately a problem with the truck. Maybe a combination of smaller issues. I probably wouldn't be quick to modify it before finding out the problem since you might confuse the issue.

A couple things to check would be the exhaust donuts where the up pipes go into the collector at the back of the turbo. You can look at them with a flashlight laying under the truck looking past the trans bell housing. They should be metallic and clean all the way into the collector. If they are discolored or black at the top, they probably need replaced.

Check the turbine compressor wheel. Make sure it has clean straight edges and they are not jagged, bent, or dusted.

Might be a plugged up cat? No real easy way to check, but if you have a bunch of backpressure you would probably suffer a bit in the mpg.

You can check your fuel pressure and high pressure oil pressure, but I would think there would be a runnability problem if they were low. Who knows? Sometimes when power slowly bleeds away over time the owner doesn't notice it as much.

If you take the valve covers off, make sure all the injectors are spitting oil from the deflector hoods. You could probably run a quick compression check while it is opened up. But, again, low compression would probably be a running poor issue more than a mileage issue.

Does he change his oil every 5K? Is he using a properly rated oil? How long has his fuel filter been in? If you want, you can give me a call and maybe I could help scratch heads with you?

tylerprochaska · 03-09-2006, 10:52 PM

Thanks guys
I havnt received the truck yet but those #'s seemed low.
as far as what he told me over the phone thats empty mpg,
I agree thats bad and I will do some investigating on it soon,

My opinion on the mods are about the same as one of you said being hes not looking for power it wont recoop the cost of mods.

being a DRW I dont think its going to be 2 great. I have a 01 and my dad has a 99.5, mine has a few mods and 4.10 grs, the other stock with 3.73 grs, neither get real great 13 to 15,empty, I have yet to see personally one of these get much over that.. my buddy 03 gets the same stock,, Maybe some of these truck (all years of turbo 7.3) get some of the #'s that have ben posted but I havn't seen one.. (maybe our fuel around here sucks? But it makes my pulling tractor haul [img]/ubbthreads/images/graemlins/smokin.gif[/img]

Anyway sorry for the long post but just wanted to check others input on this older model truck

Thanks again.. everone should be proud of the help this site provides!!!

classy_gene · 03-14-2006, 12:55 AM

I would have to say something is wrong with the engine. My '94 psd crew cab dually with 4.10's will get 17 mpg on the highway @ 65-70 mph. I average 12.5 mpg pulling my 9k pound 32' 5-th wheel camper on a 3600 mile trip running 60-65 mph with AC on high. I have gotten as high as 22mpg when we have been as National Parks and such just putting around.