Mopar1973Man

More on compression and heat. https://en.wikipedia.org/wiki/Fire_piston The key part here is... So now consider cold start and colder winter time weather conditions. Efficiency is reduce not to mention the high cetane fuels that aid in the ignition quality but have reduced BTU amount per gallon. So coolant and IAT temperatures play a key role in ignition quality and MPG numbers. Then again back to injectors if you have a good fine mist then iginition is easy but if you had large 100HP or larger then the quality falls. When I say warm I don't mean crazy hot just added warmth to promote good ignition quality. Being that the 98.5 to 02 ISB Cummins is the lowest compression ratio of all the series we need all the help we can get for ignition quality. So now look back at the fire piston and consider your fuel (tender) and compression. Then it all starts to click together a bit easier.

@65mph my egts are appx 650F no wind and outside temp about 75 deg 18-20% Engine load 40-50 HP (flywheel) 120-130 FT/LBS (flywheel) @55mph my egts are appx 550F no wind temp 75 235/85 R16 tires 5th gear nv4500 Edge Comp 5x3 +50HP injectors Vulcan Performance HX35 level road surface NO load

Again... Quality of spray. The finer the mist the easier it is to convert to vapor to go BANG! So quality of the nozzle, quality of the pop test and flow matching. So a poor quality nozzle like Edge Jammers popped and flow match will still be crappy for MPG because the spray is poor anyways. It just a dirty nozzle. This one reason I always kind of chuckle about the cold air intake. Because colder the air long to convert and loss of timing for ignition. Take notice to the IAT temp and the high marker. No fooler used. The low numbers are towing my RV.

MPG is about quality of spray. A injector with a finer spray pattern, matched pop and flow rate will produce better MPG's. Most vendors just grab 6 injectors off the shelf and toss then in a box to ship. Like mine I had Eric at Vulcan Performance do the pop test and flow match of all 6 within 3% of them all.

Something like? https://www.napaonline.com/napa/en/p/NPJP330/NPJP330_0325356452

You stripped it out it just a piece of thin sheet metal for the nut inside. So many people strip that out.

it's the illusion of timing. So stock injectors flow only so fast. Now you open up the nozzle with a larger size now the flow rate is faster so you get you fuel in the cylinder faster giving the illusion of timing advancement. Problem as nozzle size increases the droplet size does too. So you require more cylinder heat and/or boost pressure to prevent smoke. Because as boost pressure goes up so does cylinder pressure... Higher cylinder pressure means more heat. 30 PSI is roughly 1,100 PSI at TDC in the cylinder. Just remember liquid fuel will NOT burn. All fuels have to be converted to vapor before it will burn hence the black smoke issue with large nozzles.

Exhaust brake... I use mine all the time I do 90% of all my stopping with it and the last 10% which is at speeds lower than 20 MPH. So my service brakes last will over 180-200k miles. Exhaust brakes are not just a trailer or towing thing... This video is subtitled with the actions I'm performing. Take notice to the brake pedal point. This is also empty truck no trailer.

This is like machine language of a 6502 processor of a Atari 800 computer.

Hang on a second the basic data like all your gauges... Fuel level, oil pressure, volts, coolant are all on the CCD bus. Like coolant is already part of the diagnostics PID's already. so that means we should still be able to get basic data yet without all the special stuff. Now if your diving deeper like say timing or commanded fuel now I can see needing the programming mode and jumping over. Again there is a lot of data just on the CCD network we need to fish out first before jumping in deep for the super stuff.

So we are on the right track now. We now just got to poke at the data or sniff the bus and see what falls out next right?

OK... So now flipping back to ELM327 chips you can set the baud rate for anything you want. Look at AT BRD...

Here is the raw data...

So close.... Changed it to (A*.145)-28 which nearly zeros the gauge out. You math starts out at 26.62 PSI just idling. So after driving with it the values aren't quite right actually boost pressure 5 PSI shows about 8-9 on the OBDLink then it max'ed out at 18 PSI exactly which would be the boost fooler of the Edge Comp.

Just an quick update. I just make a trip up on the mountain getting ready to do firewood cutting. So this trip was just only the truck. I climbed the grade at the posted speed limit of 20 MPH for 8 miles and the most I got for transmission temperatures was 140*F that with 800-1000*F EGT's most of the way up the grade. Then proceeded to cruise around most of the forestry roads looking for firewood spots and seeing what roads and such are gate is shut or open. After traveling around up there for a total of 40 miles only seen a max temperature of 140*F and low of 130*F just drifted between to the two marks the entire time. I went from roughly 1,700 feet at the valley floor to a high of 6,500 feet the temperature up here was roughly 55*F. Now after hitting the valley floor and hitting the highway again back to 65 MPH it only rose to 140*F for the trip home. As for the valley floor temperature it was 75*F. I should be traveling this road very soon with the trailer and logs and we'll see how much it changes.

Even when I bought mine used I crawled all over the RV looking in all the cabinets, pushed on the walls and ceiling looking for soft spots, had the fire up everything verify it worked. (fridge, a/c, heater, water heater, etc.)

Like myself I lost my OEM joints well before 100k miles and switch to grease-able and now they are last well over 100k miles. I do travel a lot of dirt roads, mud, snow, salted roads, etc. Sealed u-joints there is no way to push out the water or old grease.

There is a member "Ilikeoldfords" in Missoula, MT. Sorry I don't have many people placing pins on the member map for us to use... https://mopar1973man.com/membermap/

Could be DPF filter issue? (Educated guess) Something smog wise maybe?

The whole battery disconnect thing is a myth. It will not clear error codes nor will it reset computers. There is something going on that is trip the service message. You going to need a code reader of quality to see what going on. To reset the computer just turn the key off and wait 10-15 seconds it will reboot on the next key on. As for error codes its required by law to record and hold all error codes for 40 warm up cycles before being erased.

Sounds like a near truck. OP could you post up the year of truck we are talking about. As for reading codes I highly suggest you find a actual code reader. Some of those code reader tuners are rather weak at seeing pending codes. Stop by a auto part store and see if you can get someone to read the error codes for you.

Here is the tablet (closest to mine) http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=9098499 Then the OBDLink LX Dongle https://www.scantool.net/obdlink-lxbt/ Then the Android App https://play.google.com/store/apps/details?id=OCTech.Mobile.Applications.OBDLink&hl=en I personally gave up the ScanGauge II because of its lack of logging data and limited display. The ScanGauge II is now living its retirement in my 1996 Dodge Ram 1500. As for the OBDLink will work with anything mobile wise or even a laptop with bluetooth. Now you have much better way of logging changes and effects of your tuning. I love the fact it logs all my fuel mileage day by day. You can graphically record any sensor you want.

My Dad bought a 1976 Dodge Jamboree Class C motohome. I bought it from him in 1993. When I got it he had all the paper work in the cabinet above the fridge. It been back to the dealer over 7 different times if I remember right. Also the oven valve had a propane leak that flash fire his face once lightly the front stove burner. There was several issues with wiring, stereo, propane leaks, cold start of the engine. Ownership of the Jamboree I had to rebuild the interior ceiling from a water leak, new carpeting, replaced the plumbing (water supply), 2 water pumps, rebuild the wet bath floor (water leak). Remove the oven valve could replace because it was too old. At the point of the trade in I lost the rear main seal on the engine at 60k miles so I was no looking forward to having to figure out how do that in a van head body. Then fight to replace the rear brake wheel cylinders on a 400 Dodge frame the drum are heavy! So I trade that Jamboree in on the 2000 Jayco Eagle in 2010 and the only things I've down is brakes on a front axles. 2 sets of tires now, and re done the roof with DiCor coating. Then added the solar and inverter. More or less all I got is clean up the RV, fill propane bottles and a water tank and yearly packing the wheel bearings. One reason I got a trailer and not a motorhome. So now you kind of see why I'm not really a new person plus reading other RV forums also and seeing the back and forth trips too. Some people get lucky and other OMG get absolute lemons for RV's.

From what I understand is more timing. @apache64 is telling me that his Edge Comp is flat on top end and hoping to skew the timing to give more top end.