Crappy Mileage No Matter What Tune

[Mopar1973Man]

Engine load is based on timing and drag. Turbo has nothing to do per se in engine load. My typical boost is only 2 to 4 PSI at 65 MPH. Timing is related to cetane of your fuel. Next one is drag lifts, leveling, oversized tires, etc will increase drag.

Edited December 28, 2019 by Mopar1973Man

[TheGreatWhite]

26 minutes ago, Mopar1973Man said:

Engine load is based on timing and drag. Turbo has nothing to do per se in engine load. My typical boost is only 2 to 4 PSI at 65 MPH. Timing is related to cetane of your fuel. Next one is drag lifts, leveling, oversized tires, etc will increase drag.

Well I don't have much flat where I'm from in Kansas (believe it or not Kansas isn't entirely flat) so it's a lot of up and downs quickly. Driving up a hill can be 13-15psi, down 2-5psi so I can't really tune with flat in mind, or can I?

 

So what are some tips (for after I put on my factory bed since that's next) on tuning lower boost pressures but to burn efficiently? Is that just decreasing fueling under fueling per psi? Bare with me cause I'm still learning. 

 

Or

 

If I'm all fuel and not enough air, since I run 8-10psi on average on flat road, wouldn't a bigger turbo work though? After all your are running a 60/60/12 and I'm still on a completely stock hx35, which is what, a 54/58/12? Or somewhere close to that? Granted I still have a lot of drag, but it seems a lot of the people with great mileage have bigger turbos. Me has a he351, you have your 35/40 hybrid, couple even have big compounds and are getting great mileage. 

[Mopar1973Man]

16 minutes ago, TheGreatWhite said:

Well I don't have much flat where I'm from in Kansas (believe it or not Kansas isn't entirely flat) so it's a lot of up and downs quickly. Driving up a hill can be 13-15psi, down 2-5psi so I can't really tune with flat in mind, or can I?

 

My trips to Ontario and back home. I climb 3 grades roughly 6% on all three and then rolling hills the rest of the way. Highest elevation is 4,400 feet and drop down to 2100 feet roughly. So, yes you can.

 

16 minutes ago, TheGreatWhite said:

So what are some tips (for after I put on my factory bed since that's next) on tuning lower boost pressures but to burn efficiently?

Scale the truck and then look at way so reduce weight and wind drag. Rotation mass and rotational resistance is the biggest ones to kill MPG. Wind drag is anything above 55 MPH you need to get more aerodynamic. Final gear ratio is optimal at 3.55 to 3.73 now I've got to ask what size tires are you running?

 

Your running too much drag. Advance the timing should reduce boost. The trick I use is watch the oil temperature. If your tuned correctly your oil temp should always be lower than coolant. I'm now just tipping -30*F from coolant. So if the coolant is 192*F my oil temperature is barely 162*F on semi-flat ground and cruise set at 65 MPH even better yet 15*F outside. If you advance too far the oil temp will rise more. As you retard the oil temp will fall. This is due to over advancing will heat more of the cylinder wall and the coolant near the oil cooler this makes it tough to dump heat into coolant that is already heated. Matter of fact I've just changed my timing again and just about got it nailed. Start at 13, 17, 21, 25. This dropped just about 3* of oil temp. This is all based on what the cetane level is locally to you. As cetane goes UP (45-50) the timing must RETARD. As cetane goes DOWN (40) timing must ADVANCE. This is the basis for my high idle and MPG mode.

 

16 minutes ago, TheGreatWhite said:

Me has a he351, you have your 35/40 hybrid, couple even have big compounds and are getting great mileage. 

 

HE351 and my Hybrid 35/40 are the same just about.

 

HE351 is a 60/60/9

Hybrid 35/40 is a 60/60/12

 

Optimally you should be near 0 boost while rolling. I'm typically like 0 to 5 PSI for most all highway stuff. Interstate is more like 5 to 10 PSI. Hill climb 6% maybe 10 to 13 PSI.

Edited December 28, 2019 by Mopar1973Man

[TheGreatWhite]

24 minutes ago, Mopar1973Man said:

Wind drag is anything above 55 MPH you need to get more aerodynamic. Final gear ratio is optimal at 3.55 to 3.73 now I've got to ask what size tires are you running?

I'm running brand new Warden 2s in 235/85/16 from Treadwright. I believe once I put on my factory bed I'll get my aerodynamics in line, but outside of cutting speed holes or building something to swoop the air away on the side, I'm kinda stuck till I cut the bed off.

 

27 minutes ago, Mopar1973Man said:

The trick I use is watch the oil temperature. If your tuned correctly your oil temp should always be lower than coolant. I'm now just tipping -30*F from coolant. So if the coolant is 192*F my oil temperature is barely 162*F on semi-flat ground and cruise set at 65 MPH even better yet 15*F outside. If you advance too far the oil temp will rise more. As you retard the oil temp will fall. This is due to over advancing will heat more of the cylinder wall and the coolant near the oil cooler this makes it tough to dump heat into coolant that is already heated.

Do I need to buy a oil temp gauge or is there a sensor in the Quad program that gives me the temp? Cause I've looked and can't seem to find it.

 

28 minutes ago, Mopar1973Man said:

Optimally you should be near 0 boost while rolling.

It's basically 0-1 all the way up to about 35, 5 gear is when boost really starts piling on. I can generally keep boost out in 1-4, but 5 is a little tough cause of all of said drag.

[Mopar1973Man]

Use the trans temp sensor it will fit the test port on the filter head. Trans temp on mine is just below the coolant which is my oil temp.

 

 

Edited December 28, 2019 by Mopar1973Man

[TheGreatWhite]

17 minutes ago, Mopar1973Man said:

Use the trans temp sensor it will fit the test port on the filter head. Trans temp on mine is just below the coolant which is my oil temp.

 

 

Holy cow I never would have put those two together! Thanks for the tip! I've been wondering how the heck I'm going to find out my oil temp outside of a new gauge, this makes things so much easier! 

 

Should I/ does it need some thread tape?

Edited December 28, 2019 by TheGreatWhite

[Mopar1973Man]

NO TAPE or SEALANT the sensor needs a good ground contact. Tape or sealant will foul the signal or make it not read at all. Brass is typically self sealing.

 

Passing though too. Is never use any sealant or tape on any oil fittings. The other problem is if any tape or sealant go into the oil system it could plug oil cooling jet(s) or mess up the bearings very quickly.

[TheGreatWhite]

On 12/29/2019 at 10:50 AM, Mopar1973Man said:

NO TAPE or SEALANT the sensor needs a good ground contact. Tape or sealant will foul the signal or make it not read at all. Brass is typically self sealing.

 

Passing though too. Is never use any sealant or tape on any oil fittings. The other problem is if any tape or sealant go into the oil system it could plug oil cooling jet(s) or mess up the bearings very quickly.

Got it, thank you for the tip! Still trying to figure out what to use, and not to use, tape/ sealant on.

[TheGreatWhite]

@Mopar1973Man @Me78569 @dripley is there by any chance any way to damage a VP by too much fuel pressure? I was talking to my pump guy about this whole situation. Gone through brakes and all and nothing is changing mileage wise, and he asked how much fuel pressure I run, of which I tell him at idle can be 17-20 and driving is 16-18 and he chimmed in with that being way too much and maybe even damaging the pump. Is that possible? Thought VPs could take up to 20psi just fine?

[dripley]

 The original Bosch specs were for lower pressure. IIRC that was dealt with on later versions of the VP. I have run 18 to 20 psi I thru mine for 8 to 9 years now with no issues. I did just loose my VP but it had 270k miles on it. All but the 1st 20k at the 18 to 20 psi level.

[TheGreatWhite]

Just now, dripley said:

 The original Bosch specs were for lower pressure. IIRC that was dealt with on later versions of the VP. I have run 18 to 20 psi I thru mine for 8 to 9 years now with no issues. I did just loose my VP but it had 270k miles on it. All but the 1st 20k at the 18 to 20 psi level.

So since mine was manufactured in 01 should we consider that theory as hogwash? It's still the same VP from factory with 235k on it. 

 

Some of the symptoms seem to be a tiny surge upon start up, gutless when cold, 30* cold starts take longer than they should, the other day had a long crank (but that's extremely rare).

 

If it matters at all, since we last spoke the only thing I've changed was a bad APPS (TPS) and the manufacturer said to set it at 0.55 but a buddy and I couldn't get that exactly. After calibrating it though we've had 0 problems and I've driven it about 200 miles with no codes or anything. So there's that since I know timing is dependent on throttle percentage.

[kzimmer]

I agree with @dripley. Whoever said it was too much pressure is not familiar with the VP44 requirements, and is probably thinking of the VE or P pumps.

 

For the record, a few times this winter my Fass regulator froze up and my injection pump was delivered a full 35 psi at the inlet. No known permanent damage, however mine will NOT start in this condition. 

[TheGreatWhite]

Just now, kzimmer said:

I agree with @dripley. Whoever said it was too much pressure is not familiar with the VP44 requirements, and is probably thinking of the VE or P pumps.

 

For the record, a few times this winter my Fass regulator froze up and my injection pump was delivered a full 35 psi at the inlet. No known permanent damage, however mine will NOT start in this condition. 

I was seeing that kinda pressure one day when it got down to like 6, however truck ran just fine.

 

I did unhook one of my ebrake cables cause it did appear to be slightly engaged, which actually after doing that my boost pressures at cruise have dropped it appears, yet mileage still continues to drop.

 

[dripley]

Leading up to my vp failure I started seeing lower mileage. Not as low a mileage as I remember you seeing. With all the idling I do in the winter its kind of hard to say what I saw for a drop. I was getting down in the 17 mpg range from 19,5 on the highway best I could tell. I was also experiencing some hard starting, but worse than it seems you are. I did however find another issue with my exhaust brake. Mine is off the truck for now but the elbow with the damper is still installed. I had it wired open but the wire stated failing and had partially moved towards closing. Discovered this after the new VP but fixing did help with boost pressure and mileage I believe. Kind of hard to know for sure what was responsible for what since they were both happening at the same time.

[TheGreatWhite]

5 minutes ago, dripley said:

Leading up to my vp failure I started seeing lower mileage. Not as low a mileage as I remember you seeing. With all the idling I do in the winter its kind of hard to say what I saw for a drop. I was getting down in the 17 mpg range from 19,5 on the highway best I could tell. I was also experiencing some hard starting, but worse than it seems you are. I did however find another issue with my exhaust brake. Mine is off the truck for now but the elbow with the damper is still installed. I had it wired open but the wire stated failing and had partially moved towards closing. Discovered this after the new VP but fixing did help with boost pressure and mileage I believe. Kind of hard to know for sure what was responsible for what since they were both happening at the same time.

Like I said though no matter how hard I drive it nor what tune it doesn't change a darn thing at all. Could it be an ECM issue maybe? Or should we keep looking for pump/ hard part problems?

[kzimmer]

2 hours ago, TheGreatWhite said:

I was seeing that kinda pressure one day when it got down to like 6, however truck ran just fine.

 

It happens around -30°C (-22°F) for me. I just completely drained my tank and changed fuel filters of paranoia that it was caused by bad fuel or water or something. Luckily it's warmed up to -6°C so I get a break from winter breaking things.

[dripley]

4 hours ago, TheGreatWhite said:

Like I said though no matter how hard I drive it nor what tune it doesn't change a darn thing at all. Could it be an ECM issue maybe? Or should we keep looking for pump/ hard part problems?

I think you should swap the old ECM and PCM Like you suggested originally and just see what happens. Cant hurt anything and easy to do.

[TheGreatWhite]

7 minutes ago, dripley said:

I think you should swap the old ECM and PCM Like you suggested originally and just see what happens. Cant hurt anything and easy to do.

Would I need to do anything special with my quad? Like turn it off before I pull my ECM or anything?

[dripley]

Just now, TheGreatWhite said:

Would I need to do anything special with my quad? Like turn it off before I pull my ECM or anything?

That would be a question for @Me78569 or @Mopar1973Man or someone more knowledgeable of the Quad.

[Mopar1973Man]

7 hours ago, TheGreatWhite said:

is there by any chance any way to damage a VP by too much fuel pressure?

 

Above 20 PSI you not improving anything. There return port back is too small for any more than 20 PSI. Now below this your going to be building more pressure in the VP44 casing. It very possible to blow the front shaft seal out.