Sudden loss of gas mileage?

[OrangeCrush]

When I installed the supercharger, I installed a bigger throttle body. In order to use the bigger throttle body, I installed a little box that basically allows the throttle blade to open 100% instead of only 80%.

The box is a sealed unit about 1.5" x 1.5".... it's not very big but it is sealed.

The day I left to drive my H2 to FL and had the tranny fiasco, I must have accidently pulled one of the wires from this box out of the harness it was attached to.

After some checking, I figured it out, soldered the wire in and everything was fine.

My problem now is I can't get over 8 mpg driving the truck as much like an old lady would. If I drive the truck normally, it's nothing to only get 5.6-6.0 mpg.

I don't know what may have changed and if this box could go bad but there ain't no way my H2 is only getting 8 mpg driving like an old lady.

With this little box and throttle body installed, I could get 12mpg if I drove like an old lady and average 9 with my heavy foot.

Any suggestions?

Mark

[Cesardajr]

i had a bro with the same problem with his dodge ram.
turns out the plugs were the problem, they pulled them and they had to much gap, change them out with the correct gap and like new again.

[Intercooled]

5-6 mpg is pretty dramatic. Is that what your DIC is saying? Are you actually getting 5-6mpg?

[OrangeCrush]

Originally Posted by Intercooled

5-6 mpg is pretty dramatic. Is that what your DIC is saying? Are you actually getting 5-6mpg?

That's according to my DIC. It's always been pretty accurate so I really didn't have any reason to doubt it.


I'll doublecheck it but I'm thinking I've got some issue somewhere.


Mark

[twr]

hi is your transmission fixed yet?

[OrangeCrush]

Originally Posted by twr

hi is your transmission fixed yet?

Nope...

Took it to get rebuilt. (dropped off trans, didn't take truck)

Took it back with trans in truck, they R&I'd and replace converter and valve body.

Got it back, CEL on again.

Gonna take it back this week.

Mark

PS. It drives and shifts fine, just getting a CEL light.

[twr]

hi Mark, ok after the trans is fixed check the mileage, not on the trucks computer to see where your at for sure. Then lets us know.

[OrangeCrush]

Dropped the truck off this morning and picked it up about an hour ago.

Turns out there was a defective valve (or solenoid) in the pump. It was causing the converter to lock up almost all the time.

I didn't know that would have an effect on mileage but since I reset the mileage and drove about 50 miles, I'm averaging a little over 12 mpg.

I'll check it over the next few days but it appears to be working correctly.

Mark

[twr]

hi Mark, that is why i asked if the trans was fixed yet. I thought it might be in the trans or convertor. Glad its working correct now.

[OrangeCrush]

Thanks Tracy, to be honest, I didn't even think it was in the trans only because I only got 5.7 mpg on the way to tampa with enclosed trailer in tow.

Point is, that was before the tranny blew so I figured something else was going on.

But like you said, I'm glad it's working.... I was getting tired of getting less than 8 mpg.


Mark

Originally Posted by twr

hi Mark, that is why i asked if the trans was fixed yet. I thought it might be in the trans or convertor. Glad its working correct now.

[twr]

Hi i am thinking it had the problem when you went to FLA. thats why you got chit mileage and when they rebuilt the trans the sol. worked then didn't. Sometimes its hard to find things that work then don't. Alot of times they will not set a code. The trans guy should have felt it on his road test, but it may have not done it when he drove it.