O4 379 MBN 24234 C15 Cat Poor fuel and power

I thought I had an injector fixing to crap out on me; glad to hear it's one of the perks of owning an MBN.

 

droy you NEED a different ecm buddy!!!! lol

They all did that i guess, talked to a buncha guys with the same issues when i first got mine, i did injector cut out tests to be sure and they all came back strong so i just ran it like that..... Sure was annoying as hell though!

 

The fuel temp wire is the one that gives you the power, its 50-60hp, it wont cause it to smoke any. The boost wire causes the smoke as its telling the ecm it seeing over 8psi of boost all the time to eliminate the lag..... CAT dont open full fuel flow to the injectors till the ecm sees 8psi of boost so that boost wire AKA smoke wire gives instant throttle response by dumping fuel in as soon as you touch the throttle but gives 0 power.

Also you CANT use that boost wire on the MBN, just the fuel temp, the boost wire will cause the ecm to freak as it will see over 30psi with it.

 

I never messed with that electrical stuff myself as i hate anything electrical so i cant tell ya. Whats good with the harness though is that its easily removable vs. soldering a resistor in.

 

You probably have the two wire fuel temp harness. In case you have the three wire, and want to try it-
First, the disclaimer...
I found this on another web site that I seldom frequent. I do not know if this trick works, nor do I know anyone who has tried it. IF I had the three wire setup, I WOULD try it, as I have gotten some pretty good info on that site also.

Fuel Temp wire harness modification:
(1) Cut the orange wire, leave it like that.
(2) Strip a bare spot on the black wire.
(3) Cut white wire, solder white wire toward sensor to the black wire.
(4)Solder 150 ohm resister to the other white wire, then solder the other end of resister to the black and white wire you soldered in step (3).

The poster stated that this was good for about 40 hp, and about .5mpg on his truck.

If any one comes across instructions on how to do a two wire fuel temp harness, I'd appreciate them letting me in on it. I THINK I found an electrical supply house that sells electrical plugs that are compatable with the Cat wiring plugs, so a fellow could rig up a stinger to just plug into the harness. Going to order a couple, and check them out.

 

Its a 2 wire deal, all 70 pin ecm'd trucks are, the older 40 pin were 3 wire, unless the 2WS 3406E 70 pin is 3 wire but doubt it.

 

The valve adj should help your mpg. Running a gear down will cost you fuel! So, stay in top gear whenever possible. Also , you need to progressively shift it, under 40 mph you don't need anything more than 1500. Once your in top gear and running in rolloing terrain, let the engine pull down to 1200 rpm beforeyou downshift, you'll find a lot of those hills won't require downshifts. Remember, on a Cat your foot is asking for rpm, on the volvo your foot is asking for power....point here is the difference between Cat's full range governor and Volvo's Min-Max govenor.