WVU Dodge

This is kinda a multi part question. The 99 I bought a couple months ago has and 4.10 gears, which i think is the biggest part of the fuel mileage problem. But the previous owner told me he has seen up to 24 mpg out of it on a trip to Baltimore. The best I have seen is 15-16. I upgraded from stock size tires to 35's, and still 16 mpg. I checked my APPS sensor, found it to be off and adjusted it, and i'm getting 17 mpg now. I know these trucks can get 22 mpg but I just dont know if its possibel with the lower gears.

Second part: When driving on the interstate i noticed the pedal is almost buried in the floor to hold 70 mph up hills (probably 5% grade). This is even after I adjusted my APPS. I dont remember it being like that before the 35's, so that is probably some of the problem with that, but I dont know.

Part 3: I have a shudder at launch. Dont matter 1st or 2nd gear, idle or not, it bucks somewhat violently. The only thing I have found to help it is to slip the clutch more than i would like at launch. Adjusting the APPS did nothing to help this


My question is this: are any of these problems related and what could be causing them? When I found that my APPS way off, i got excited thinking that was going to cure everything, but it really didnt help anything.

Other information that may help is a stock truck and I believe a stock clutch. I do not have a fuel pressure gage but hope to have one in by the end of the month.

Thanks in advance to anybody who had the patience to read this far down the page and respond.

Adam

J BODY

Perhaps his "24 mpg to Baltimore" was 95% down hill and he drove it at 45 mph with a tail wind. I think you current mpg number sound about right for the combo. Keep track of it on paper and see what you come up with. The overhead accuracy can vary.

On your "power" issue I would check the air charge system and make sure their are no boost leaks. Check the lift pump psi, be sure you have a good fuel filter and air filter. After that my personal opinion is that I can't see how people can drive these trucks in stock form and be satisfied. I work on them daily and even before I bought mine I noticed quite a bit of difference in the trucks that would come in the door. I found that most of the RV'er we see had "bombed" their truck in one form or another and it definately improved the drivability and power. When I drive a "stock" truck anymore I just chuckle and think what the customer is missing out on.

neveragain

Very Sorry to hear but ; your truck has what mine has.

First the low power could be that the injectors need to be replaced. Have them pop tested that will tell the story on them.
The shutter at take off is very likely what mine has is a bad voltage problem ( SORRY EVEN WITH THE OSOCILLOSCOPE READINGS CRY-SLURR AND *** IN'S HAS NOOOOOOOOO CLUE WHAT THE PROBLEM IS ) My suspiction is that it is fromm the PCM but have checked the alternator and batteries. Not a good check of the wiring harness but some to date!!!
PM me if you would like to see what the voltages look like from the vp-44 and some of the other spots I have lots but one or two pages will tell the story. Give me a Fax number and will send them to you.

WVU Dodge

Yea as far as the low power is concerned, I was kinda just figuring that was because I have not drove a stock truck for a couple years and wasn't used to it. It can't get outta its own way from the factory. But I know that launch shudder aint right.

I do not have a fax machine for you to send me all of your data. I'll just have to live with it for now I guess. But i bet it is the same thing as what yours does. I was thinking maybe it was bucking because of a timing problem also, so i dont know if a smarty or something would help that. I was going to buy one regardless so maybe we'll see.

Tate

Before I changed my clutch, my truck would buck quite a bit if I tried leaving in second. First wasn't so bad. Once I removed the clutch, you could see there was quite a bid of crud built up on the friction surfaces, and between them. With the new clutch, its a lot smoother now.

piperca

I've got a 99 2WD and I get 15 around town and the BEST I've EVER gotten on the freeway is just shy of 18.

I think the previous owner of your truck was quite the salesman!

scottsjeeprolet

Hold your horses there buddy. Before takin the motor apart lookin for the power loss problem let's check the basic's first. We, You need to check you fuel pressure first! Have it checked or get a guage, this could be your problem, have it scanned for codes. change the fuel filter, change/check the air filter. Do that first and let us know then we can go from there.

WVU Dodge

I'll have to check the basics first like you said. When the previous owner told me 24 mpg gallon I was kinda skeptical with the 4.10 gears but didn't question it because I had a 1990 that got about 22 and with these new trucks that are controlled by a brain I figured it was possible. I know the guy and he wouldnt lie to me about it but maybe it was flat ground and below the speed limit.

If i'm get 17 mpg tank after tank thats fine, I just dont want there to be something wrong and do nothing about it. At 150,000 miles I got nothing to look forward to with the break in period and every tank getting better mileage.

My main concern is the clutch, the rest I think is just the nature of the truck. The more vehicles I drive the more I think that 1990 cummins was the best vehicle I'll probably ever have. I haven't had anything since then that can replace it. The sad thing is someday I'll be looking at my 99 and saying "they just don't build em like they used to"

Thanks for the suggestions fellas. It will give me some things to tinker with

pocketchange

Change the trans and diff fluids too.
If you have a NV5600 trans, don't worry about getting the overpriced Texaco/Dodge fluid, I've been using Royal Purple and changing @ 25/30K.
Add a filter cover from Eaton/Fuller Part #FUL K1444 for the trans.
I've got a 1 Qt. cooler cover for sale if anyone wants one ($50) plus freight.
pc

storx

i just wanted to throw in my 2 cents.... a bad or worn out torque converter can kill fuel economy...