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Before asking who has the best kit, I want to hear from the forum members (if any) that have experience with propane or W/M injection before I start believing the advertising hype and one off tests. I also want to do a lot more research on the subjects. I have to ask, if the propane injection gives those results consistently and is SAFE for the truck, driver, and engine, why haven't long haul trucking companies jumped all over it for the big rigs? The propane is metered into the turbo inlet and I suspect in quantities that create an explosive mixture even without the diesel fuel. Just wondering if that creates a potential hazard in the intercooler like using starter fluid does. I did read that Methane even when mixed needs to be handled with caution (read protective gloves, clothing, and eye protection) because it is bad stuff for you to be exposed to.

Propane Injection. From Wikipedia, the free encyclopedia Propane is a three-carbon alkane, normally a gas, but compressible to a transportable liquid. It is derived from other petroleum products during oil or natural gas processing. It is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves and residential central heating. A mixture of propane and butane, used mainly as vehicle fuel, is commonly known as liquefied petroleum gas (LPG or LP gas). It may also contain small amounts of propylene and/or butylene. An odorant such as ethanethiol or thiophene is added so that people can easily smell the gas in case of a leak. Energy content The energy density of propane is 46.44 megajoules per kilogram (91,690 BTU per gallon). Weight per gallon The density of propane at 25 degrees C is .493 grams per cubic centimeter. Converting gives 4.11 pounds per gallon. Thus, Propane weighs approximately 4.2 (+/- 0.1) pounds per US liquid gallon, at 60 degrees Fahrenheit. Propane expands 1.5% per 10 degrees F. Price per gallon (from an internet search) 10/18/2010 Prices range from a North Dakota average of $1.62 to a Rode Island average of 3.26 Marketing description from ParleysDieselPerformance.com “Diesel Propane Injection – Propane injection for diesel engines is a time tested way to safely improve your horsepower and increase your diesel fuel mileage. When used properly, propane injection will keep your engine cleaner with less carbon buildup and cleaner oil. Propane is a high octane fuel. The slower and longer burn of propane helps your diesel fuel burn more thoroughly, increasing power, torque and fuel mileage. This is one of the best performance modifications for towing, since the use of some performance chips can lead to excessive exhaust gas temperatures when hauling large loads at high speeds, especially up significant grades. With a diesel propane injection system burning propane at approximately a 1:4 ratio to diesel fuel (1 gallon propane per 4 gallons diesel) the increase in exhaust gas temperatures will be minimal and the fuel economy gains will typically pay for the cost of the propane. Propane injection will work for all diesel engines including older mechanical systems.” Marketing claims Adds up to 100 Horsepower & 100+ Ft. Lbs. Torque Substantial fuel economy gains (notice the subjective wording) Excerpt http://moparmuscle.automotive.com/67354/mopp-0604-2001-dodge-ram-propane-injection/index.html (without permission) Propane Injection For Dodge Ram Cummins Turbo Diesel - Propane - It's Not Just For Grilling Anymore Installing MSD's Digital Propane Injection On Your Cummins-Powered Truck By Dave Young “We tested the system with the truck both loaded and unloaded and were impressed with the improvement in acceleration. We initially programmed the system to give us 100-percent capacity at 5 pounds of boost and expected to feel the system's "hit" when the propane was added. The system operated seamlessly, however, and the only indication that it was working was the speedometer's rapid acceleration to not-quite-legal speeds. Even when only programmed to 50-percent capacity while towing our 10,000-pound, enclosed car trailer, we found we had power to spare. No matter what incline we climbed, simply rolling into the throttle produced not just sustained speed, but acceleration, with transmission downshifts now a thing of the past. Exhaust temperature was also noted to be some 50 degrees cooler for a given driving parameter. A quick trip down the eighth-mile showed an improvement of six-tenths of a second and 5 mph when using the propane, with traction now limiting how hard we could launch the truck. Amazingly, it also makes economical sense to use the system when driving daily. As a function of the extra power on tap, the economy of our truck improved drastically. In a controlled test at 65 mph, our highway mileage in an unloaded truck with the propane shut off was 24 mpg, not bad for a heavy dualie. With the propane injection on and set to initiate at five pounds of boost and give 50 percent of the systems capacity, our mileage increased to an amazing 44 mpg (factoring the diesel fuel used only)! Over a 100-mile test, we used 6 pounds of propane from our 30-pound tank, which cost $18 to fill at the local propane supplier, so the propane used for the test cost $3.60. Diesel fuel for the 100 miles was 2.27 gallons at $3 per gallon for a total of $6.82 in diesel fuel. Added together we get a total of $10.42 for the 100-mile test using propane. Without propane, we used 4.17 gallons of diesel at $3 per gallon for a total of $12.50, so we saved over $2 on a 100-mile test using propane. In addition to the cost savings, the use of propane provided us added range, which allowed us to shop for fuel, saving additional money because we now could go to the next exit or even the next state to find cheaper fuel. Even better results were obtained when towing-we saw mileage increase from 14 mpg without propane to 24 mpg when using propane injection. Our truck's range now had no problem exceeding the endurance of our bladder, even while towing our car trailer. We can derive mathematically that it doesn't take too long for the system to pay for itself, especially when diesel fuel in our area is hovering around the $3-per-gallon mark.” Wow, that’s a 55% fuel economy increase with an unloaded truck, and a 58.3% increase with a 10,000 lb trailer. Hmm… If all this can be taken at face value, the $800.00+ cost of the system could be worth the effort financially. Water/Methane Injection Marketing description from ParleysDieselPerformance.com “Provides better fuel economy (1-3 MPG), more power (50-100 HP), and lower Ehaust Gas Temperatures (150°-300° F)” Cost of Methane $33.80 + shipping for 5 gal. http://www.worldwideracingfuels.com/ProductInfo.aspx?productid=790072 Marketing description (FAQ) from snowperformance.com http://www.snowperformance.net/faqs_type.php?type=diesel 1. What are the benefits of Water/Methanol injection? 1. Greatly reduced EGTs - Decreases of 250 degrees F are common using a 50/50 water/methanol mix. Increased EGTs are an engine killer in today's performance diesel world. 2. Low cost power - Where else can you get 50-100 HP for as low as $549? What other modification does all these things with one system? 3. Greatly increased air charge densities - 3-5 psi boost increases are common with liquid intercooling. 4. Decreased emissions - increased combustion efficiency means less particulate matter and NOX emissions. 5. Fuel economy increase - increase your fuel economy up to 10%-15% (1-3 mpg). 6. Great for towing - more power/cooler EGT's to haul the heaviest loads. 2. Why is Water/Methanol injection so effective on Diesels? Unlike gasoline engines, the power in a turbo diesel is largely a function of fuel. The problem with continually adding fuel is that you create an over-fueling condition and reach a point where the exhaust gas temperatures become prohibitive (over 1300 degrees F). A 50/50 water/methanol mix will decrease EGT's approximately 200-300 degrees F while increasing power 50-100HP. Power is increased through: • Air charge cooling - Water/methanol usually lowers air charge temps over 200 degrees F. Low air temps makes denser air charge which provides more molecules of oxygen for combustion. • Combustion conditioning - the methanol acts as a combustion catalyst as well as a cooling agent. Water vaporization inside the combustion chamber increases torque and power output through "the steam engine" effect. Where else can you get this kind of power with cooler EGT's, reduced emissions, and more fuel economy? 3. Is this technology new with Turbo Diesel? Water/methanol injection has been used extensively for years in high performance truck/tractor pullers. With the elevated boost levels required for peak power, water/methanol is a common means of cooling the intake charge and reducing exhaust gas temps. Also, truckers have used water injection for years to increase fuel mileage. 4. What power gains can I expect? In diesel applications, no additional tuning is needed to maximize the benefits. • A cooler, denser air charge is now delivered to the combustion chamber – this allows more diesel fuel to be burned than before. • The methanol in the injection fluid burns as a fuel. This directly impacts power production. • The water vaporizes in the combustion chamber, creating rapidly expanding steam which pushes down on the piston to create additional torque. The extra power produced depends heavily on the concentration of methanol used and the volume injected. Typical power gains in 5.9L and larger applications with a 50% mixture of water/methanol are 50-100 WHP and a 100-150ft lb-ft increase in torque. 5. Can the Snow Performance system improve my fuel economy? Yes. The MPG-MAX™ systems are designed to do just that. Both the diesel and gasoline MPG-MAX™ systems are specifically designed to inject a very small and precise amount of water/methanol under normal driving conditions such as accelerating away from a stop light or driving up a slight grade. • Diesel MPG-MAX systems benefit from the methanol directly due to the fact that it combusts as a fuel, allowing for brake specific fuel consumption (BSFC) to be reduced. Typical gains are 10-15% better fuel economy or 1-3 MPG. In some cases and in independent testing, gains of up to 30% have been observed in diesels. 6. What fluid can I use in my system? • Boost Juice®: This is the best fluid to use and is Snow Performance’s 49% methanol, 51% water mixture that can be shipped to your door or picked up at a local dealer. (If you are using your washer reservoir as the injection tank, Boost Juice® is a great washer fluid – works as a de-icer!) • Windshield Washer fluid: Only if it is blue in color and rated for -20 deg F. This means it is safe to use and made of about 30% methanol, 70% water. If it is another color or another temperature rating, do not use it. It should NOT have any extra additives or features. • You can “spike” your Blue -20 Washer fluid to a 50% mixture by adding 3 12OZ yellow bottles of Heet® gas-line-antifreeze to every gallon of washer fluid. • Mix your own: You just need to make sure the methanol is “neat” and contains no lubricants or other additives. We recommend a 50% mixture. • Ethanol: It is not as good as methanol, but it can be used as a 2nd best option if you can’t find methanol. It can also be mixed with water up to 50%. • Do NOT use E85 or any other fluid with gasoline mixed in. It will destroy the fluid delivery part of your Boost Cooler® and instantly void the warranty. • Isopropyl/Denatured Alcohols: These can be used, but are not as good as methanol. They have a lower BTU, or energy content, and a lower latent heat of vaporization (fancy way of saying how much heat they absorb) as well as a lower octane rating compared to methanol. 7. Why Methanol? Methanol is an extremely clean fuel with an excellent cost/benefit ratio. Its high latent heat of vaporization also makes it an excellent air charge cooler which means a denser mixture and more horsepower. Because of these characteristics, it is a better fuel than ethanol or isopropanol although they will work in a pinch. It is extremely toxic and should be handled with rubber gloves in well ventilated areas only. Care should be taken to avoid skin contact. 8. Is Methanol Safe for my Diesel? Methanol makes an excellent adjunct fuel. Because it has a cetane number of 4CN, it makes safe power without spiking cylinder pressures. 50/50 water/methanol is also very resistant to detonation. It is in fact used as a detonation suppresant in our gasoline systems. This allows for injection without worries about pre-ignition even in very high boost applications such as sled pulling and drag racing. "combustion of neat methanol alone results in a cetane number of 4CN with reduced PM (smoke) and NOx. " see SAE Technical Paper #940326 "Combustion and Emissions Characteristics of Minimally Processed Methanol in a Diesel Engine" 9. Where can I purchase methanol? • Snow Performance sells a 51/49 water/methanol mix as Boost Juice™ (see products). If this is used exclusively, Snow Performance can lifetime warranty a system so long as the free registration card is sent in soon after purchase. • Methanol can generally be purchased where racing fuels are sold. Also, most gas line dryers like "Heet" are simply methanol. Suppliers of industrial chemicals can also supply methanol for a very reasonable price. • -20 degree F rated, blue windsheild washer fluid is acceptable for use as well, and is availble at most service stations. Although some fluids rated to under -20 degrees F contain glycol and other copolymers, most windshield washer fluids are up to 40% methanol. Try to find one that displays "contains methanol" on the label and is good to -20 degrees F, with no additives or special ingredients and is blue in color. • Methanol can be purchased on the web at www.worldwideracingfuels.com and www.hiperfuels.com. • Additionally, many sprint car drivers and circle track and drag racers use methanol as a primary fuel. They often have methanol on hand and will even sell methanol that has been un-sealed for a long time at a very low price. Just be sure that the methanol has NO additives or lubricants (such as top lube), as they are not needed and can damage the pump. 10. Can I use pure methanol? While all components of Snow Performance systems are designed to be able to handle pure methanol, it is not recommended for a number of reasons. • Safety: Straight methanol is easy to ignite and burns with an almost invisible flame. • Performance: Water absorbs twice as much heat as methanol in the intake and inside the combustion chamber. Water cannot be flash-ignited, so has almost an infinite octane number. In the government studies for WWII piston-powered aircraft, 50/50 water-methanol was found to be the best fluid to use for auxiliary fluid injection. • Tuning and Engine reliability: Injecting 50/50 water-methanol will prevent over-injection. If too much is injected, it will quench the flame front and the engine will bog and lose power. If too much straight methanol is injected, this will not happen, as methanol is very forgiving of rich mixtures. This could instead lead to explosive backfires, cylinder wash, etc. which will not happen when 50% or more water is in the mixture. 11. How much range will a tank of Water/Methanol provide? Diesels use more fluid than a gasoline application, and are in heavier load states more often. • On a Stage 1 or 2 system, the factory washer fluid tank on a pickup truck (usually 1-1.5 gallons) will last a tank of fuel. This is for normal mixed driving with no towing and some aggressive acceleration. • On a Stage 3 MPG MAX™ used for towing, the 7 gallon reservoir (included with the MPG MAX™) usually lasts 1-2 tanks of diesel fuel. In an un-loaded state, the 7 gallon reservoir will provide about 1000 miles of range. When towing, the 7 gallon usually lasts about 500 miles. • A standard Stage 3 system will use about 1 gallon of liquid for every 75 miles of towing. Many Stage 3 users take advantage of their stock washer tank or the special universal fitting included in Stage 3 Snow Performance diesel kits with a custom large capacity tank. Be sure to use a solenoid upgrade for any reservoir mounted in the rear of the vehicle.” So they say 3.5 gal of methane will last about 500 miles (towing) will keep the EGTs down and provide about 1-3 MPG increase for a cost of about $23.66 and unknown shipping costs in Methane. That’s right around $.05 per mile or around $.66 per gal of fuel used based on 14 mpg towing. Questions I have. First what are your (if any) experiences with either Propane or Water/Methane injection. Is it cost effective? Has anyone used both at the same time to both add power and keep cooler EGTs? Is either one practical for everyday use with the added hassle of monitoring the reservoir tanks? Jim

Hmmm.... If I had a set of stock injectors I would put them in to test that theory, but I don't. I have my RV275's in the truck and the larger +80's on the bench. I'm planning to get the +80's pop tested and set to 310 bar. I'm also going to ask if the shop can flow test the nozzles to see how close they are to each other. I still think that the winter fuel blend has a lot to do with the stalling because last spring we were having quite warm days and the truck still was stalling until either I added injector cleaner or got summer blend fuel. On top of that the truck was garaged all winter and spring. Right now I have my horse trailer in one of the garage bays to rebuild the electric brakes. On a side note with the truck parked out side, the high idle (not 3cyl) kicked in for the first time. I turned it on with the smarty last spring. The high idle coupled with the exhaust brake brought the truck up to operating temp real quick. . --- Update to the previous post... John, I suspect you are right about the 3X disk converter having more internal drag and aggravating the issue. I intend to add some inj cleaner to the fuel today to validate that it again temporally fixes the problem. The colder temps didn't seem to have an effect on the truck coming back through Canada from Montana (the truck was parked at night in temps as low as 22 degrees). It was only when I put in fuel here in Anchorage last week that the problem started, and the night time temps here were 10-20 degrees warmer than the Canadian temps were at night on the trip.

I don't think I would use the beads. I'm just skeptical about having something sliding around on the inside of my tires. You know it's gotta be making dust and you have already been warned about the dust clogging the valve when checking tire pressure unless you add air first. Then there is the issue where, if you pick up a nail and go to get it fixed, will they fix it or not because of the beads inside the tire. You know the fix a flat liquid when put in a tire makes such a mess and tire shops generally won't fix any tires that have the liquid in them. As for water/meth injection, I have no knowledge or experience with it. I have been intrigued with the idea of propane injection, because I read it is a catalyst for diesel fuel and makes it burn at a much higher efficiency, and have wanted to research it further. Maybe I should start a thread on the subject.

I check the water separator about once a month and have not found any water in it yet. Just changed the filter 6k miles ago. Don't have a drawstraw I'm using the factory pickup. Fuel pressure is 16.5 at idle and 15.5 to 16 running at 60 mph. Jim

John, You are supposed to drink the espresso not pour it into the trucks fuel tank. I think your truck has had so much it's shaking. I seem to remember years ago there were disks you could buy that had a steel tube around the circumference with the balancing media in the tube. They bolted on with the lug nuts, but I haven't seen them in years now. JC Whitney used to sell them. Anyone else remember them? If they are still manufactured they might be an option for John. If the front end components are good I would get an alignment done by a reputable shop. Here in AK for a 4WD it costs about $80.00. If that don't fix it then I would remove the tires and rims and thoroughly clean all the road dirt from the inside of the rims and have the tires rebalanced. Tire shops will not clean the crap out of the rims before balancing either new or re-balancing old tires. I have had tires balanced and then hit a chuckhole in the road that dislodges the dirt on one side of the rim and throw the tire out of balance. If that don't cure the shakes then I would consider a steering box brace. http://www.pscmotorsports.com/Dodge-Trucks/Steering-Stabilizer-Brackets/ Jim

So I got my first fuel fill of the Alaska winter fuel blend last week and immediately the stalling when put in drive is back just like my thread of last spring on this problem. http://forum.mopar1973man.com/showthread.php/1584-Problems-Stalling-when-shifting-to-drive-and-hard-starting-when-hot.-Ideas?highlight= I got to thinking after I read JohnFak's thread on the same issue with his truck where new batteries fixed it. http://forum.mopar1973man.com/showthread.php/2401-New-One-truck-stalls-when-moving-into-gear?highlight= Entry #20 I checked my batteries and found they were 5 years old. Well, they are Costco's kirkland brand with a 100 month warranty. I looked at the chart of refund on the batteries and found I was at the 30% refund point. I pulled the batteries and took them to Costco and indeed, they did refund 30% of the purchase price after looking up my sales receipt in their computer (I had misplaced mine :-) ). Then I went and got 2 new batteries (again Kirkland with 100 mo warrenty), and installed and trickle charged them overnight. Didn't fix the stalling. When it was stalling last spring I had edge +80 injectors. I have since replaced them with RV275 injectors (new), so I'm sure that it isn't the injectors as the stalling happens with both sets of injectors. Last spring I found that adding injector cleaner ended the stalling until I added fuel once again. I've been getting my fuel at the Fred Meyers stores. I think I'm going to try another fuel source and see if that helps. I hate to use additives other than 2cycle oil. Any other Ideas? Jim

ISX is right on the money with his advice. John do you have an HY35 turbo on your truck? If so if you found a good HX35 and put a 14cm2 exhaust housing on it it would reduce your temps a bit and you could put a boost elbow on it to get up to 35+ psi. However with what you are saying your egts currently are, you are just fine. the turbo will take temps under 1230 with stride for a good period of time. It's when it goes over 1230 for more than 30 seconds at a time you will start having issues. To get the best mileage, if you are in hilly country accelerate slightly going down the hills and up the start of the next one then allow the excess speed to slowly bead off going up the hill. Your steady foot will give better mileage than the cruse control. In towns keep it rolling when possible when coming to a stop light. Watch how the truckers drive they know how to optimize fuel economy. Jim

Haven't hand calculated my mileage yet. The trailer is a 16' enclosed horse trailer 6.5' tall inside with a Vee front on a class IV hitch, not a fifth wheel or gooseneck. Scan gauge II told me my averages were around 13.4 going down. coming back I had less load (only had a partial back haul this trip) I'm guessing around 3500 to 4000 lbs including the trailer. I have a smarty and reprogrammed the ECM for the trip back with the economy + boost + timing program (#3) and set the timing advance to aggressive. The Scan gauge was then reporting 14.5 mpg. I kept my speed between 55 and 60 MPH. Total mileage was around 7500. When I'm pulling my living quarters gooseneck horse trailer (17000 K loaded) I get between 12 and 12.5 mpg. I would guess that your fifth wheel is quite high above the truck and has a lot of frontal area for wind resistance causing less mpg. What speeds are you driving? My guess is your best mileage will be right around 55MPH.

John - I just got back to Anchorage on the 11th from a trip to Montana pulling about 9K and never saw transmission temps above 135 in lockup. But then again the outside air temps were generally below 60 and down as low as 15 in the night time hours. The powered coolers are great.

Casey, where in Alaska are you? I'm in Anchorage. John based his install on my install. I've run mine in (and out of AK) for over three years with no problems so far. Jim

I have a PacBrake on my truck, a couple of years ago I hadn't used the brake for quite a while and the butterfly froze in the open position. I had to take the elbow with the butterfly off and disassemble it as far as I could. I removed the butterfly plate but couldn't get the screw on the housing loose to get the shaft out. I ended up soaking the shaft and elbow in deep creep seafoam for three days before I was able to work it loose with a large channel lock pliers. I bought some of the synthetic lube from PacBrake and use it on a regular basis as well as use the brake often to keep it loose and working.You should be able to (with the truck shut off) move the actuator arm on the butterfly shaft with a pliers if it is not frozen. Two other problems that can occur with these brakes: one dirt can stick the electronic solenoid vacuum controller valve that mounts on the intake horn mounting bolt. The solenoid has a button on the end that can be pushed in with the truck running to test the operation of the valve and will actuate the brake vacuum cylinder that operates the butterfly. If it don't actuate the cylinder then either the solenoid electronic component don't work or isn't getting power. The other common failure is the vacuum cylinder is leaking and won't hold a vacuum on the internal piston seal when the brake is actuated. In this case the cylinder must be replaced with a new one from PacBrake it is not rebuild able.If you call PacBrake the techs will email cleaning instructions for the solenoid valve it is quite sensitive as to how it is cleaned without damaging it.

The two items that lowered EGT the most was the 4" exhaust and the 14cm2 housing.You already have a 4"exhaust. but your HY turbo has a 9cm2 exhaust housing (can you say hot), other than that it is essentially the same turbo as a HX35 which has a 12cm2 housing. The HX will be a little slower spooling up than a HY but not much.You might try to find a good HX35 and put it on you can get them for under 300 if you look.You might PM TURBOLVR he may have a good one that he will sell you, not sure if he is on this forum but he is on the cummins forum.Anyway with the HX you can use the adjustable boost elbow to regulate your boost and at the same time get lower EGTs. It would also enable you to try a 14cm2 housing later if the 12 didn't lower the EGT enough. The 14 spools a little slower than the 12.

Have not had any of the injectors pop tested.The factory injectors in 2007 gave me 20+ mpg on the highway running empty, and 12.5 pulling a 17K gooseneck living quarter horse trailer. That was with the factory 12cm2 turbo exhaust, factory exhaust pipe, and a K&N filter in the factory air box. Before I installed the +80 injectors I put on a 14cm2 turbo housing, BHAF, and 4" turbo back MBRP exhaust to lower the EGT.The +80 injectors in 2009 and last May gave me 13.5 pulling 8K enclosed trailer and 14.8 running empty (scan gauge II average numbers on long highway runs).Before the trip in May I put on a HX35/40 turbo with the 14cm2 housing and was not happy with it on the trip. I have now put the 12cm2 housing on the turbo and have been much happier with it. So that's one more factor that has changed. But I wouldn't think it would have much of an affect on mileage, just EGT and turbo spoolup.The RV275 injectors (also on the scan gauge II) are showing 16.2 average on the highway.I haven't pulled with the RV275 injectors yet but am leaving for Montana next week with another load of around 8K.Now I know that many things besides the injectors affect mileage and the intake and exhaust modifications also affect mileage, as well as the fuel blended for the time of year.However according to all accounts and claims I've read the intake and exhaust modifications I made should have affected mileage in a positive way increasing it not decreasing it.As I said before I'm thinking of pop testing the +80 injectors and getting them set to 310 bar to see how they perform for mileage then. I bought them but never had them tested as the vendor assured me they had tested them.I bought the RV275 injectors new also with no exchange but didn't have them tested either.If I test the +80 and install them I will test and set the RV275 injectors to 310 bar also.It just won't be in the immediate future as I've got more runs to Montana planned and need to keep the truck up and running.Jim

Good info in that doc. It also states the solenoid opening (triggered by the ECM and electronics in the vp44) controls the timing of the injection cycle. That would seem to say that the pop pressure don't have anything to do with the injection timing. So that brings me back to my question of whether the pop pressure (if set at 310 bar) helps with atomization of the fuel for more efficient burn and better mileage.

So what is the proper pop pressure? 4500 + or - 250 psi (310 bar)?

Injector pop pressure and it's possible affect on mileage is a subject I have not seen discussed on the forum.Does the pop pressure of the injectors affect the atomization of the fuel enough to have a noticeable effect on fuel mileage?I suspect that it does.I'm on the third set of injectors in my truck trying to get a good balance between towing power and economy.I also realize that today's fuel is not as good as the fuel a few years ago.On the stock injectors in 2004 I was getting great mileage. Then I got a set of +80 injectors using the stock ones as exchange. Mileage went way down hill. I have since put in RV275 injectors and gained some of the mileage back but it still isn't anywhere near the original stock injectors.I still have the +80s and am thinking of taking them in and getting them set to the highest pop pressure I can to see if that helps the mileage any.Does anyone know what the pop pressure range for injectors on a vp44 is?

OK Mike you have just proven wrong the people who say that (with the engine off) fuel cannot get past the VP44 internal vane pump regardless of the LP pressure.Now the question is:Would higher LP pressure push more fuel through and open the vp44 return relief valve for a higher flow rate?

WRONG, Alaska is 3.55 to 3.79 per gal. :cry:

Only on the early 98.5 engines below a certain serial number (don't have it handy) was it mandatory to replace the injector tubes. On those engines the tubes would not reseal properly. So unless the tubes are damaged (seating surfaces scratched or deformed) you should not need to replace them.

Switching (opening)the signal wire that locks the converter so it can't lock will NOT throw codes and put the truck in limp mode. I know because I put in a switch to do just that and it works fine. I have a CoPilot transmission controller that controls at what speed the TC locks. I normally have it set to around 43 mph for lock and it unlocks at about 37 mph. That equates to about 1100rpm before unlock. If I give it more throttle at 1100 rpm in lockup in OD it lugs the engine so I can switch the TC lockup off while staying in OD and the engine will rev and accelerate the truck. I put it in so that when towing heavy loads in hills I can switch it out of lockup on going up hills to prevent the engine from lugging down to a lower power output level to maintain speed. It won't cause any codes to be thrown or put the truck in limp mode. Jim

If you can turn a wrench you can install a PacBrake. A lot depends on which one you get, mine replaced the 45 degree elbow on the turbo, A switch on the accelerator peddle, a vacuum valve under the hood, a simple toggle switch, and a tap into the vacuum system. Not sure about the install for the newer compressed air driven units though.

No noticeable diff in power, wasn't tracking mileage. Sorry Jim

My stalling problem is solved, turned out to be winter fuel.I got fresh summer blend fuel into it and the stalling is gone.I've driven from Anchorage to Montana and there is no longer a hint of stalling when shifted into drive.ThanksJim

My stalling when going into drive or any forward gear is solved.Turned out to be the fuel. when I got fresh fuel through it the stalling cleared up and it now gives no hint of stalling at all.Thanks guysJim