rickf

You are going to give someone 325.00 for a pump that will have the same thing done to it that you can do with a 60.00 kit. And you know the vacuum parts works on yours, you have no idea of the history of the one you are getting. Just my :2cents:Rick

Sounds feasible since the computer will base timing and fuel on the readings from the MAP sensor.

No matter what you go with stay away from the Chinese specials! You get what you pay for.

If you want to cool the VP more with fuel you are going to have to open the return line hole up in that return valve. Now you get into the can of worms, how much pressure Does the pump itself actually require to run and how much is being used for cooling. The original specifications were written around the factory pump. We are mostly running much higher volume, positive displacement pumps. Pressure is not needed to achieve the volume like it was before. We can get very large volumes of fuel at lower pressures. I would be willing to bet that with a 100 GPH pump you could double the size of that hole in the return valve and still maintain 14 lbs. of pressure, plus have a massive amount of return flow to cool the pump. Now, let's make that cab of worms a little deeper, is there anything in the pump that is designed to actually transfer the heat from the computer to the fuel? A heat sink grid? I doubt it. Just smooth surfaces. You will reach a point of diminishing return at some point when you are moving enough fuel that it is not absorbing the heat that is there because the fuel is not staying there long enough to absorb heat. This will also happen in an engine which is run without a thermostat. The water flows through the radiator so fast it does not have time to give up its heat and therefor the engine overheats.I will make a concession to the 1/2" lines in one respect. If you want to keep the pressure low but still run the same volume then the bigger lines will make sense but as has been stated everything in the system has to be upgraded to the larger size, not just the lines. Keep in mind the inlet size of the VP-44, if it is 3/8" then it is all moot.

ISX, You had mentioned that I might have a stronger spring in my overflow valve and that is why the higher pressure. That could be a reason but not in my case, here's why. When I first got the DDRP pump my pressures were 8lbs. at idle and 0 at WOT! Turns out that they sent them out with the wrong relief valve springs so Geno's sent me a new spring. With the new spring in the pump the pressures are now 23lbs. and 18 lbs.. The pressure in this case is being regulated by the bypass on the pump. The DDRP, as are most aftermarket pumps, is a gear rotor pump. If it is rated at 100 GPH it WILL flow 100GPH regardless of the pressure. Pressure is a byproduct if restriction in the line. In this case it is the overflow valve in the DDRP, you just have that little hole to force fuel through. A gear rotor pump is a positive displacement pump so if you deadhead the line you will get thousands of pounds of pressure! (Or something will break, more likely) So my pump is rated at 75 GPH and that is what it is flowing. Now the issue is how much is flowing through the VP-44 and how much is flowing through the bypass on the DDRP to maintain the set pressure. Without a flowmeter it will be hard to figure it out exactly but if you put a hose on the return line and run it into a gallon container and start the truck and measure how much you get in a minute and multiply by 60 you will have the GPH of the return line. At idle the engine use will be negligible. that will give a pretty good idea of how much is bypassing internally in the pump to maintain pressure. Very low tech but workable.RickP.S. I love throwing the contradictory monkey wrench into these formulas.:evilgrin:

Yes, done, but with a stock pump. Mine is putting out 23 lbs. at idle and 18 at WOT with the Quad on. 5 lb. drop but well over the safe limit, on all stock lines and fittings and filter.I don't think you can compare rotary vane pumps with gear rotor pumps. Totally different principals.

I know that fuel line size has been beat to death here and everyone SWEARS you HAVE to run 1/2" line to get any performance at all. I am wondering why that is so. Think about this for a minute. Assuming you get 10 MPG fuel mileage, most of you get at least that much. At 10 MPG you use 6 gallons of fuel at 60 MPH. At 5 MPG you would use 12 gallons per hour and at 2.5 MPG!!! you would use 24 gallons per hour.Now, has anyone ever taken the line off of the VP-44 and put it into a gallon container and bypassed the pump for one minute? I am guessing that it would about fill the container in a minute. I have not tried it yet but I will once I relocate my pump. That would be 60 gallons per hour out of the stock lines. This, by the way is based on an upgraded pump, in my case a DDRP. I have not done this exact test yet but I will when I relocate my pump. I have forgotten to tighten the banjo fitting on the outlet of the filter and had the truck still start all the while blowing fuel EVERYWHERE! I know what you are going to say, "well it can't pump that much under pressure". This is true up to a point. Relief valve is set at 14# I believe and anything over that is bypassing back to the tank so yes it can if it can maintain the pressure. Also the pressure would only affect the pump output and not the line flow established in the previous test.So basically here is what I am saying. You have a pump rated at 70 GPH, lets cut that by 50% for the pressure loss, no way are you losing that much but just the hell of it. That leaves 35#. Let's also say you are getting 2.5 MPG. (You need a new/bigger truck!). That STILL leaves 11 more lbs. than you actually need. Note that these are very drastic figures and no way are you ever going to lose that much to line loss or are you going to get that kind of mileage. But the mileage would compensate for the WOT blasts. I see no real reason for needing 1/2 inch line other than peer pressure.Opinions?Rick

When it is locked you can push on the throttle and the rpms will not jump up, they will rise as the speed goes up. When unlocked the rpms will vary with load. Keep in mind that when locked if you push hard enough it will unlock so as not to lug the engine. You will know when it does. And yes, it does unlock when you command it to go into or out of O/D manually but will lock back up quickly. You can leave it in O/D for the most part and let it choose it's own gears unless you are towing real heavy, over 6,000 lbs., and in very hilly terrain.

I know Centramatic has been in business a long time and I am sure this has been thought out but when somebody mentions any kind of shim on a front wheel I instantly so NO. That goes right along with running recaps on the front. Just my opinion.

Haven't touched the front end in a year. Like I said, I think that combined with the issue I have had for over a year of the slow pedal return this push back problem is just telling me it is time to rebuild the booster. I really need to find out if it is the same part number as a one ton Chevy from the eighties. I already have two of them on the shelf.Rick

Exhaust brakes and ice are a bad combination. I don't have one yet so I don't know how hard they pull you down but I drove for many years on big rigs with Jakes and that is why they have a switch to turn them off and some have the option of less cylinders. On a wet road with even half the cylinders if you were empty it could slide the tires and that was an instant jackknife! Ice, forget the Jake altogether. By the time you realize what is happening it is too late to do anything about it, even if you switch it off you are already committed to the slide. Chains would definitely help but it is a bad habit to get into because you don't always have the chains. While out there it is mandatory to run them a lot of places here in the east it is illegal to run them! They just declare a state of emergency and you are not allowed to go out.Rick

Vacuum pump? I don't understand where the vacuum pump would come into play.The more I think about it the more I suspect the hydroboost. I have had the issue with the slow return on the pedal for years and now this. The pump would not affect the pedal return but the hydroboost could so now............ who has the best prices on a QUALITY hydroboost unit?Rick

No ABS light or codes and it is a different feel. This is right at the top of the pedal travel, not down low where the brakes are actually activated. Plus I don't think the anti-lock would be felt in the steering.

I have an issue that appears mostly when cold but it is getting more frequent. If I hit the brakes even halfway fast the pedal will kickback at me and then go down. In really cold weather I can feel this action in the steering also which leads me to believe it may have something to do with the pump. I bought this truck a couple of years ago and the brakes have always had a lag on releasing. The light will stay on for a couple of seconds after releasing the pedal so I just wanted to get some opinions. I have the usual wander on the highway and I figure I am going to have to replace the box at some point but I do not think this is part of that issue. This is a TWO wheel drive truck. I add that in because everyone always assumes all these trucks are four wheel drive when they give a diagnosis.Rick

You would have to find a way to make sure the transmission did not shift while locked up or things would probably break. An automatic is designed to shift under a fluid connection, ie; the converter is not locked so there is a cushion.

Could you also pm me a quote on the brake? Any pictures of the turbo outlet needed would help also. Rick

Not good but if they empty the tank and all of the lines and replace the filter you should be alright. I mean ALL of the lines, take the lines loose all the way to the pump and drain/bleed til you get clean diesel. Then loosen the injector lines and bleed them out to complete the process. As was mentioned, as long as the seals and O-rings survived you should be alright. A quarter mile means it did not run much through at all before quitting. I would almost thing E85 might run in a diesel, you need high compression in a gasser to run it.

If you put Teflon tape ONLY on the threads you will have no issues with anything in the system. I have seen people get lazy and just slap it on and it overlaps the end and then you have a problem because that piece will get cut off as you thread it on. Also only use sealants on tapered threads, never seal any type of straight thread fitting. They should have a gasket or o-ring seal. I have seen brass fitting leak many times, they are usually sealed from the factory also.

Check your voltage at the pump and as far as the thread sealant that stuff should work but if you have any doubts just use Teflon tape. I know that when my grid heater comes on I drop 5 lbs. of pressure.

A link to the videos would be nice.

Just so you know, A FASS IS a gear style pump and it can be jammed by debris from the tank. A rotary vane pump will pass most debris trough the pump because the vanes can retract.

True, wasn't thinking of that side of it.

IF it is a turbo seal and it is leaking bad enough to produce visible smoke you might want to stop driving it until you get that fixed. That is a lot of oil and could possibly lead to a runaway situation.

The worn exhaust side turbo seal could be very important since it is a source of unregulated fuel. I don't think I have ever hear of that causing a runaway on a 5.9 though. White would be raw fuel, Valve adjustment? 300,000 is a lot of miles if it was never done.

I need a new wiring harness for mine, one of the pins is bad in the plug at the box and losses contact off and on. I was going to order one about two months ago and hedged. Guess that is what I get for procrastinating. Anybody have one?Rick