Last year I inherited an old IDI of another brand.it had been sitting in long-term storage for nearly 4 years. In that time I've put approximately 4000 miles on it. The injection pump was cranky from day one. Hard Smokey starts, poor acceleration etc. A local diesel tech suggested the stanadyne fuel treatment. I finally found a bottle locally last night at a local tractor supply store. This product truly does work.Within 15 miles I noticed the engine running much quieter, hard starts are gone, and certainly increased performance. The other half of that bottle is going in the 300 today. Just thought I would pass it along.

You can usually find it as you did in a tractor supply store, or a marine supply store. I too had excellent results using their products.

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96 E300d

It's been a while since I looked at it but ULSD has been a problem for injection pumps and was a frequent topic on Cummins forums for a time. Discussions have slowed down possibly because the vehicles are older and there are fewer of them with most of the problems documented. I run 1 oz of 2-stroke/gallon of fuel in the Cummins and have 100,000 mi on the injection pump without problems. 2-stroke is easier to find than Stanadyne and less concentrated so easier to avoid over dosing.

Lubricity Additive Study Results - Diesel Place : Chevrolet and GMC Diesel Truck Forums

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Most of the additives change the cetane rating of the fuel. Which changes the burning characters of the Fuel.

US Diesel Fuel tends to ride on the lowest possible cetane rating which may or may not reflect what the manufacture intended. Then as in the case of my own 1984 vehicle the Diesel Fuel it was designed to run on is long gone and in an attempt to reduce emissions there has likely been 4 major changes in Diesel Fuel since that time.

People frequently say that when the do a diesel pure the engine quiets down (less of the diesel fuel knock) and after the purge their engine goes back to the normal sound when it is running on mostly only diesel fuel.

"Cetane number (cetane rating) is an indicator of the combustion speed of diesel fuel and compression needed for ignition. It is an inverse of the similar octane ..."

https://en.wikipedia.org/wiki/Cetane_number

The Fuel injection pumps that took the hardest hit from the changes in Diesel Fuel are those that have aluminum housing that have parts that slide against the aluminum. That would be Staynadyne/Roosamaster and the Bosch Fuel Injection Pumps that similar to the ones that go on the older VW Rabbits. Both types of Fuel Injection Pumps will so quite a bit of wear to the housings.

In your particular case it is kind of undetermined what the additive did to fix anything.

If after you stop using the additive it still is working fine it is likely you loosened something up. I not using the additive returns you to the problems you may need to retime the Fuel Injection Pump or do work in the Injectors.

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84 300D, 82 Volvo 244Gl Diesel

It is a Stanadyne..DB2.It would stall cold,and developed a surge/lope after the cold adv solenoid closed upon reaching near operating temp.The tech thought it was possibly a sticky governor ring(I have no idea what it is)I will watch it and see what happens after the product is no longer in the system.

Stanadyne additive works well on my 300d non turbo. Smooths the acceleration. I have also used 2 cycle oil but I read somewhere that adding oil to diesel fuel was not a significant lubricant effect.

Sent from my Nexus 7 using Tapatalk

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
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1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

What would set Stanadyne apart from say a Chevron Techron or Liquid moly diesel additive?

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Why I will never do business with "DieselKraut" again

http://www.peachparts.com/shopforum/mercedes-benz-used-parts-sale-wanted/378935-why-i-will-never-do-business-dieselkraut-again.html

my old days I found one quart veggie oil,made my engine,with no sound,like a m104.Mileage shot up 2 mpg on hwy,and you could feel the fuel mixture with fingers,and it was slippery.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

I used to rebuilt DB2s and I don't know what the guy was speaking of either. But, I can guess.

The advance piston is at the lowest portion of the Housing. Most of the advance pistons are steel and ride in an aluminum bore. Any water in the fuel will build up in the bottom and can rust the advance piston.

There is a pin that goes through a hole in the middle of the advance piston and it is attached to what is called the Cam Ring. The Cam Ring is steel and it rides on the inside diameter of the injection pump housing. When the advance piston moves the Cam Ring rotates and advances or retards the timing.
If something is binding on any of the above stuff the timing is not going to work properly.
During rebuilds it is common to find the bore of the advance piston worn oversized. And, you can get oversized pistons and hone out the bore (the factory has reamers for that but everyplace I have been hones the bore out).
If where the Cam Ring rides inside of the fuel injection pump housing is worn out need to get another housing.

Another issue is there is 2 little pistons that supply the high pressure that goes to the Injectors. There is no springs on the pistons. As the rotor in the DB2 passes a port from the Fuel Supply/Lift Pump (built into the fuel injection pump) the fuel pressure and volume as adjusted by the metering valve and the time the port is open pushes the 2 pistons apart. So only the Fuel Pressure and volume to that. And there is not much pressure available to move sticky pistons.

I am trying to open a site with more info. But, I attached a picture and you can see the Cam Ring (though it is cut away) and the advance piston setup. I had forgotten about that fact that the Head Locating Bolt usually has a Valve in it and that can also cause issues with the advance.

Here is as site with info on the DB2P: https://www.waybuilder.net/sweethaven/MechTech/Automotive01/default.asp?unNum=4&lesNum=3&modNum=1

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84 300D, 82 Volvo 244Gl Diesel

I’ve been using it as a cetane booster and lubricant for about 20000 miles. It shouldn’t make a big difference on an otherwise healthy engine.