Engine/Transmission (1998.5 - 2002) MPG Decreasing

[Sticks]

It's not so much gum up the pump, as wear it out. Water makes for an awful lubricant, and will ruin a VP and injectors in short order.

The gumming up is when people start running bio (chicken fat) in their trucks. End result is the same, trashed pump and injectors, and plugged fuel filters.

 

[CM_Guest]

Actually modern ULSD will leave all kinds of "gummy" deposits in a fuel system. And those deposits can create "failures" that aren't failures at all. We use an injection system flush to fix those "failed" components pretty regularly. Over-the-counter injection system "cleaners" won't touch most of that stuff. They may prevent it if used properly but once it's there, they won't get rid of it. What we run is a little different produce that replaces the fuel in the injection system so the engine runs on it for 20-60 minutes. You just plumb the reservoir right into the suction and return fittings at the engine and fire it up. I've been told that there's nothing that will fix a "failed" injector, but we do it quite often. Of course the product we sell is made and sold by the engine manufacturer to cut down on their warranty costs, too. But yes, a LOT of water will destroy any fuel system. That isn't what we've seen this winter. Mainly it's lines that are out in the open that are "freezing" rather than gelling. And part of it is accumulated moisture in the tank from condensation. Our Kenworth machinery-hauler was "gelling" when it was 15 degrees this winter. It never has before. That's why I don't buy that "good" truck stop fuel. And I don't know why anyone imagines that high fuel turnover = quality. I buy my fuel at the CO-OP and my truck was fine at -25. You don't get crappy fuel when you buy it where farmers buy theirs. Gotta feed the cows, you know.

 

[SnoKing]

CJ, the ECM and PCM in the 24V trucks do not have any fuzzy logic to learn about ones driving style. They just are what they are! I think are 2004 Buick Rainier has that feather, but not there in the Dodge Truck. It does has a temperature sensor that controls TC lockup and extends that when cold.

Chris

 

[SnoKing]

Vaughn, Thanks for the picture. Will look for it tomorrow and might spray some lubricant on it just in case it is rusted in place. Do not want to snap it off and then will have a bigger problem to deal with. From the picture and what can remember of the engine layout, a mirror would be a great help also. It has got to be right near the firewall also so not a lot of room to work in but will manage as best as can. Have a good set of deep sockets to get over the sensor also. Might make sure that use 6 pt vs. 12 pt so do not round it off. If can get a wrench in there will do that instead but leverage might work better with a ratchet. Do not have an exhaust brake, just about 133K miles of travel.

IAT sensor has a rubble seal, so spraying anything will do no good as the seal protects the threads from outside issues. You need a spark plug socket without the rubber insert, an extention about 6" long and a 3/8" racket. Go around behind the transmission kickdown cable. Got to do it by feel. Been sure to lift tab when unplugging the cable. Helps to be tall with long arms and I still had to stand on a milk crate.

Chris

 

[tnpete]

Checked mine today, it had some black stuff on it.

But not bad at all for a motor with 43,000 miles. I will say it was easy to get to, only wish the fuel pressure gauge was going to be as easy.

But then again mine is in a 2005 Chevy Kodiak c5500 so I can just take the dog house off and its right there in the open.

Pete