Engine/Transmission (1994 - 1998) Better MPGS

[rnolen]

I know that this maybe opening a can of worms, but I need everyones advice. I am trying to get better MPGs out of my 97 2500 4x4 5spd. I am getting 16 MPGS in town and want to get higher. It seems to me that I should be getting a little bit better than what I am with out advancing the timing or anything like this. I did not buy this truck for the MPGS but the price of fuel hurts. The truck just turned 60,000 miles so I am adjusting the valves tomorrow and in the next few weeks getting the timing advanced to 15. 5. I changed the fuel filter 4,000 miles ago with the oil and filter. I am also changing these soon. I have straight piped the truck and KDP Killed it. Will an AFE Mega Cannon or 4'' exhaust help? I am also wanting to put some guages on it but I have been told that If you put the fitting of the pyro in a pipe you have to stay with that pipe or get a new fitting. Is this true? Do I maybe have a bad overflow valve. Please help with this.

Thanks A lot

russ

 

[Blackcloud]

You're on the right track with the direction you are going. Changing the exhaust and intake will help it breathe better,but only with minimal increase in mpg. Put the egt in the exhaust manifold where it should be,then you don't have to worry about it if you change the downpipe. Overflow valve probably isn't a solution either.

 

[rnolen]

thanks for the reply. I know there are others out there with suggestions. I just did a search about this stuff and found that If your speedo is off it will affect your numbers. To make a long story short mine is off about 3-4 mph. The local police department has one of those radar machines out buy the house to let you know how much you are speeding. When the speedo is 45 the radar is saying 41. This thing is really fun because its on a straight piece of highway and I like to put the foot into the truck and see how fast it will jump. Anyway, from what I understand that will bump my calculations a bit.

Thanks

russ

 

[Blackcloud]

If you have 4. 10 rear end ratio,that will not help you any either.

 

[D. Showan]

rnolin. If your speedo says 45 and your only going 41. I hate to tell you but you need to correct your MPG down not up. Thats assuming your odometer is also reading miles faster than actual.

 

[San Felipe Bob]

1)Check your fuel pressure.

2)Keep your boost below 10 psi when driving.

3)Check tire pressure.

4)Don't get your hopes up My 974x4 auto with 3:54's gets 14 to 15 mpg around town.

5)Keep your speed down I pick up about 2 mpg better at 60 than at 80mph.

6)I just set the timing to 15. 5 this weekend.

still on my 1st tank. Seems to have more power on the bottom.





SFB

 

[rnolen]

Just got done adusting the valves. None of them were to tight or loose, but they were not in line. Made a difference in the way it idles, power, and hopefully MPGS. I know people have a lot to say about this subject, come on. Were in the exhaut manifold do you guys recommend putting the EGT probe?

Thanks

Russ





97 2500 4x4 straight piped and KDP Killed. More to come

 

[JIM S.]

45=41..

My speedo is off by 4-5 MPH in the 35-40 range... but anything over 65-70 its right on... . even at 100... speedo and hiway patrol were only 1 mph off (radar said 100, speedo said 101) ... so I would check it at a higher speed and see what the diff is. I do it on the freeway. one mile at 75 mph takes 48 seconds. (60 divided by time(48)= 1. 25. 1. 25 times 60 =75)) .

Jim

 

[tfrane]

I have the same truck as yours (high gears) I get 20 mpg on the highway empty (16 with RV ) muffler gone, K&N filter, 15*, all Amsoil,Horton Fan,100k on speedo.

Don't trust them radar checks on the sides of the roads,there way off in these parts, compared to freeway odometer checks.

Tim

 

[Blackcloud]

Go to the TST site. You will find real good instructions on egt probe location and installation.

 

[wcjp]

I normally average 19-20mpg. Staying under 70mph helps gas mileage. Also, don't race light to light.

 

[Gray 5.9]

Bleed your injectors after a fuel filter change. Not doin it costed me 3 mpg,s and ajusting valves. what a diffrence.

 

[Got Smoke?]

Originally posted by Emerald5. 9

Bleed your injectors after a fuel filter change. Not doin it costed me 3 mpg,s and ajusting valves. what a diffrence.

Would not bleeding the injectors really cause that?!!?



Makes me wonder, I've put 2 fuel filters in since I bought the truck and I'm getting ready to do another. I do however have some 300 Marine Injectors that need to go in!

 

[RedRamer]

pyro location

I always enjoy this article.

Do a search for the word PYROMETER and you'll get the lowdown on which kind and where to install.

ALSO, read the pAragraph that starts with "liquid filled pressure gauge" for some idea on how to get better mileage.

The whole article is great.



http://www.dieselinjection.net/articles.html

 

[illflem]

Originally posted by Got Smoke?

Would not bleeding the injectors really cause that?!!?

If it does it would be a first one on me. The injectors only need to be bled if the rig runs out of fuel or a bunch of air enters when the system is opened up for work/filter change and not fully manually bled. Most times even then if you can get the engine to fire and even run on just two cylinders it will bleed itself.

 

[RedRamer]

Now that's what I was told when I bought this truck also.

This last week-end, I'm switching over to a new bed tank and testing it out with 5 gals in it, I ran out of fuel twice.

Both times I floored it and turned the crank on/off for about a minute and it fired up.

Surprised the heck out of me.

I think if you run out of fuel it stops at the lift pump and can prime itself backup again.

Do you think maybe I got lucky?

 

[illflem]

What you are doing by bleeding the injectors is restoring a prime lost to air in the injection pump by allowing it to pump at low pressure.

The injection pump will also suck so you can sometimes get away with a dead lift pump until you break open the system allowing air into the injection pump so it loses it's prime. That's one of the reasons why you often hear folks complain that their truck was running great until they changed the filter and now it won't start even though it's been bled as far as the filter.



If you can get the engine even just barely running the higher speed that the injection pump is turning vs. just cranking is usually enough to clear any air from the system and the engine will run normally in less than a minute without bleeding the injectors. Another way to get around bleeding injectors is to pull start the truck, again it's the higher speed of the injection pump that gets things flowing.

 

[Gray 5.9]

I've noticed a good diffrence in the way my truck idles and starts, when I've bleed the injectors. After I've installed the new filter and got as much air out as I can manually at the bleeder, I start the engine, then slowwly crack open each injector and get a fair amount of foamup out of most of the injectors, until I see nothing but a solid stream of fuel. I might have a bad line some where, where air is getting in, I don't know. bu this is what works for me.