Engine/Transmission (1994 - 1998) MPG (again)

[datablitz]

I have a 1995 2500 4x4 long bed ext cab automatic transmission. i have been getting about 13mpg after installing a #6 tst plate. i think i was getting closer to 17 before hand. would i get better milage if i put the stock boost elbow on? or is there something else i should look into? i was hoping to actually get more milage from the upgrade, but i was wrong. and the ****ty part is that my truck isnt that much more powerful, other than in 4th gear locked up..... i am considering a new torque converter also. i would like to get back to 17 or even 20 mpg if possible.



thanks for any help, and sorry for posting a milage issue while there are so many already on here. the average temperature here has been about 30 degrees also, if that matters.

 

[stressedout]

Trade that #6 in for a #10 and a 3k GSK. You will think you got a rocket strapped in your bed! You have the same truck i have and i know how slow it is in stock form. All of my add-ons have made my truck perform like a new HO. [High output that is]

My mileage on the first tank after the mods was about 16. 5 and i was running the hell out of it. i am currently on my second tank and will check the mileage in a few days.



Keith

 

[datablitz]

i'll see if i can swap a #6 to a #10... . and see how that does... . will i see much less power if i don't do the GSK?



What about the boost elbow? does it hurt milage much?

 

[stressedout]

Should have the same amount of power,but it will not rev up as quick. GSK springs are easy to do when you are messing with the plate,you half way there. Do the springs you won't regret it.

I use a Boost Master, it takes the place of the waste gate and is adjustable. The boost elbow hole is plugged. My mileage is the same, maybe better

Do all of this,and when you test drive your truck you will look like this:--)



Good luck,

Keith

 

[mikel]

The '95's don't like to rev, get the GSK it's good advice. Then decide how you want to deal with the sloppy transmission. The stock torque converter is real "loose" on these trucks, that's why it doesn't feel much faster. All you're doing with that loose torque converter is making heat in the transmission fluid until lockup.



FWIF, I get 19-20 on the freeway and 16-17 around town if I'm not driving like an idiot.



Good luck,

Mike

 

[datablitz]

only reason i would put off the gsk is beacuse i am trying to save a few bucks at the moment... ... but i will look into them when i have some extra cash sitting around (and about 10 other things i want to buy) thanks for all the help everyone.

 

[Andy Redmond]

Ck. your fuel psi (20 at idle 30 at rated rpm), if low look at the filter restriction, overflow valve, , lift pump output below spec. etc.



Your timing may have slipped below oe specs too.



The plate makes good ponies but doesn't usually work as well with the gov. springs as the #10 and #4 plates.





Let us know what you find.



Good luck

Andy

 

[jimk]

milage

Originally posted by Andy Redmond

Ck. your fuel psi (20 at idle 30 at rated rpm), if low look at the filter restriction, overflow valve, , lift pump output below spec. etc.



Your timing may have slipped below oe specs too.



The plate makes good ponies but doesn't usually work as well with the gov. springs as the #10 and #4 plates.





Let us know what you find.



Good luck

Andy

I have been that road. I have the exact same truck with a #6 plate. When I first got the truck and did not know about the tdr I was on my own. I got 15. 5 or 16. 5 mpg and it was a dog. I got the truck knowing that it was a dog. I assumed it was a fuel filter> Wrong. Things that I changed out, lift pump, overflow valve, fuel hoses, cleaned the fuel screen, freeded up the exhaust, and all netted 0 . Finally I set the timing up, and it was a lot at first, I got 19. 5mph or a little more. I have since backed the timing to 17. 5 and the mileage did not change. One time had a problem with clamps on the inner cooler becoming loose and my mileage dropped off. I also have slotted the stock plate and slid it all the way forward, along with the couple of clicks on the governor springs. Slot the afc housing and modified the inside of the housing for more rack travel. I bought a 6 tst plate and I should have got a 10. I had to adjust the lever a Piers recommends. I am going to install a restrict or in the cruse control to help mileage. I could probably tighten up the afc housing an help the mileage a little. At least you have the TDR to help you out. lol jim

 

[datablitz]

i have a new filter, lift pump, and screen. havnt checked the timing or overflow valve

 

[jimk]

timing

Originally posted by datablitz

i have a new filter, lift pump, and screen. havnt checked the timing or overflow valve

If you decide to set your timing be sure to use the right cpl and there is two that I know of for the 95. I have installed the 3k governor kit also, I plugged the waste gate also. Be sure to check the inner cooler clamps as they can loosen off and you will loose some boost. I have heard of a easy check for timing. When you start your truck and after you have good oil pressure rev up the engine, does it sputter or rev up? Slow timing will cause the engine to not rev up when cold. Now this is what I was told and I hope that I got it right. I don't like to rev up my engine but I tried it once and it will rev up, no problem. LOL jim

 

[Andy Redmond]

Bosch also has a tsb for exactly what Jim is describing, involves overflow valve. If you have low fuel psi, sputtering, white smoke etc. (classic symtoms of retarded time) will occur, Particularly when cold. It goes on to say replace the part # ending in 086 with 093 (which is not longer available) it has now superceded to a 101 which is a sealed unit meaning we can't tamper with the spring, spring shim etc to boost fuel psi. Your 95 was likely effected although way out of a warranty for the part and labor now.



Search under my name, in the past I've posted the correct part # and pasted the Bosch TSB.



I think Jim makes a valid point though, provided you have decent fuel psi. If you v'e added a lot of fuel, it might be a little cold blooded until operating temps are achieved.



Good luck

Andy

 

[jimk]

overflow valve

Originally posted by Andy Redmond

Bosch also has a tsb for exactly what Jim is describing, involves overflow valve. If you have low fuel psi, sputtering, white smoke etc. (classic symtoms of retarded time) will occur, Particularly when cold. It goes on to say replace the part # ending in 086 with 093 (which is not longer available) it has now superceded to a 101 which is a sealed unit meaning we can't tamper with the spring, spring shim etc to boost fuel psi. Your 95 was likely effected although way out of a warranty for the part and labor now.



Search under my name, in the past I've posted the correct part # and pasted the Bosch TSB.



I think Jim makes a valid point though, provided you have decent fuel psi. If you v'e added a lot of fuel, it might be a little cold blooded until operating temps are achieved.



Good luck

Andy

I don't remember the name of the diesel engine, but there is a overflow valve out of a pump that can be used and it will increase the pressure in the p7100. This may not be of any value. I wish I had some one like Andy to help me when I first bought the truck as I would not had to part change to find the problem. Easer on the pocket book to just check the pressure. lol Jim

 

[datablitz]

i am going out of town for the weekend, and when i get back i am going to have the fuel pressure checked.

 

[K5IP]

I also have a 95, although mine is a 5spd. I put a tst #6 plate in it an also had a big reduction in milage, especailly in local driving.

I used to get around 18 mgp unloaded, now it is around 14. The performance is much better, but the smoke (incomplete burning of fuel) is terrible. No adjustment of the afc housing, star wheel or fueling valve seem to help. All other items, overflow pressure, timing(15. 5 deg) fuel lhoses, etc. all corrected. It is possible that I have a pump or injector problem that I have never figured out.

This plate is going to come out,and the original is going back in.

Rog

 

[Forrest Nearing]

Rog,



what kind of boost levels are you seeing?

 

[anomad]

Another '95 5speed here. When I first put in my TST plate, its been a few years mind you, the smoke was something to behold and the mileage dropped the first tank because I couldn't keep my foot off the floor.

After adjusting the star wheel it only smokes when it should and the mileage came back up to the low 20's on the highway.



Interestingly, here in AK we run #1 diesel (even in summer) and it doesn't smoke nearly as much as #2. But mileage and power take a small hit too. I can get 20-21 in the summer, but in the lower 48 I could get 22-23.

 

[K5IP]

Forrest,

It limits at about 28 PSI, even at my altitude (7500FT). TST says that is about right.

Rog

 

[Forrest Nearing]

Rog, crank the boost up to ~35 if you can. that'll clear up some of that smoke.



Forrest

 

[K5IP]

Forrest,

The smoke isn"t bad under full load, actually pretty clean at 28 PSI of boost, and if I crank the star wheel back enough, there is no smoke and also a subsequent loss of power results.

Perhaps I should not have jumped in to the post as quickly as I did, I only wanted to provide one more data point.

In reality my truck has always been kinda somkey at low speeds, just off the line, and perhaps the #6 plate has amplified these problems.

History:

When new, the truck went back to the dealer 5 times for excessive smoke and missing under cold conditions. It actually misses on one cylinder until it warms up for several miles. Then, it belches a great cloud of smoke and starts running on all six.

The dealer first admitted something was wrong and did change all the injectors. No help. Finally they said they wanted $250 to alalyze the engine to see if something was really wrong. (It was still new at this time, so I objected to the $250) Since none of their proposed analysis had anything to do with the injector pump, we parted ways .

Subsequent tests by Cummmins shops indicated that perhaps the rack was not engaging all the valve bodies linearily just off idle. They tried hard to discourage me from further investigation by indicating they would charge $600 to remove the pump, calibrate it, fix any valve body problems and reinstall the pump. They indicated it just wasn't worth it.

In a recient check with another cummins mechanic (for a timing check) confirmed the other Cummnins diagnosis. he indicated that Dodge warrants the engine to be free of defects, but not necessarily perfect. I understand this completely and do not expect perfection and my Dodge really does run quite well.

I think, from what knowledgable Cummins folks have told me, is that one of the cylinders is loading up with excessive fuel and does not ignite untill everything gets warmed up. Increasing the fueling with the #6 plate only aggrivates the problem.

In both cases, I think TST makes good product as does Cummins. I just happen that I suffer from a "build up of tolerances" which combined with high altitude operation, provide less than desireable results.

Rog

 

[Forrest Nearing]

I hear ya... my combo has some quirks, but I just drive around 'em having cake and eating it too can be expensive sometimes... I'll just eat cake



Forrest