Rebuild my own Injection Pump

[Mr. Bone]

Hello,

Has anyone embarked upon getting a rebuild kit for a Stanadyne injection pump and doing it themselves??? It sure is a hell of a lot cheaper! I'm pretty handy so it seems to boil down to using the right "core" or used pump. How do i know if a pump is worth rebuilding or not? Moreover, because i have a G30 Van it's almost impossible to see the injection pump let alone get any numbers off of it to what type of pump i need . . .any thoughts there??

Thanks for your time!

[gmctd]

Rebuild kit is o'rings and shaft seals - how will you flow-test it for correct plunger\rotor and rotor\head clearances?

Requires a Bacharach\equiv to test for flow and injection pressure capability.

[Mr. Bone]

thanks for the reply. I am coming at this completely blind, that is why is created this post. There are no threads regarding this topic within this site so i figured i'd breach the subject at least.

How about the option of rebuilding it and administering the tests you mentioned by a "professional"?

thanks

[gmctd]

Could work, if the "professional" trusted that you'd correctly rebuilt the IP - they'd prolly insist on redoing it.

Not a comment on your abilities, but time is money to any service business.

If yours is leaking past the throttle-shaft or\and the advance mechanism, but ok otherwise, then yeah, go for it - those can be done in-frame, if you're not assuming decrepitcy with age

[Mr. Bone]

thanks for the reply. there is nothing wrong with the one i'm using. I simply don't want to be put in a situation where i need one (because this is a daily driver) and i have to pay through the nose to get a replacement in a timely manner.

What are your suggestions for having a back up IP?

Thanks

[gmctd]

Hit the local boneyard(s), might find a rebuilt IP on a scrapped engine - I found one at pic-a-part for 'bout 50bucks, had the late 6.5-type housing, which I needed for my worn -4911 due to excessive camring and advance piston clearances.

I'd also put 8oz of ashless 2-stroke motor oil to each full tank of fuel to protect the one in the truck, now - ulsd isn't formulated to take care of the purely mechanical IP's like the DB2 and DS4 series, where the fuel is the sole lubricant

[bbbear]

I'd also put 8oz of ashless 2-stroke motor oil to each full tank of fuel to protect the one in the truck, now - ulsd isn't formulated to take care of the purely mechanical IP's like the DB2 and DS4 series, where the fuel is the sole lubricant

I've driven diesel autos for a few years, but this is my first diesel truck. My 6.2L, which I bought a little over a week ago, came with detailed logs from day 1. The original owner had also added a custom 2 door shell and carpit kit, Racor Brown ( 2 micron ) filter/water separator, tac, exhaust temp, engine oil temp, and transmission temp gauges, and a lot of other electrical stuff such as a remote lock and alarm, and lights to the inner camper shell, etc. It was impressive, so I called him. He said he rarely drove it over 3000 RPM, and the original IP had aluminum inner parts. When it gave out, he replaced it with one with stainless steel inner parts. He also advised me to occaionally add a bit of ATF to fuel.

Is there a replacement IP with stainless inner parts, and would you advise adding ATF to the fuel?

[gmctd]

Good question -

Heard of a stainless steel .357 Magnum, but not a DB2 - anyone else?

The only aluminum inner part is the inside of the aluminum main housing and cover - else is steel but for the electricals, fuel oil keeps it from rusting.

Ashless two-stroke motor oil is formulated for combustion chamber service, leaves no residue(s) - Diesel fuel is a light oil, so they combine well.

ATF has stuff in there to keep seals soft, keep clutch bonding-cement from deterioration, protect the electrical harness insulation and the plastics in the solenoids, and keep the coil wiring from oxidation - woodja want that stuff in yer Injection Pump?

Well, maybe, cause it's got all that stuff in it, also - seals, plastic, insulation, solenoids, wires, etc.

But the IP seal compounds are formulated for Diesel fuel, not automatic transmission service.

And ATF is not formulated for combustion - 2-stroke oil is.

ATF is not formulated to lubricate a 1700psi injection pump - 2-stroke oil has no formulation to damage that pump, and will burn with no residue.

Try it - you'll like it.................

[Mr. Bone]

Do you have any opinions on the lubricity of biodiesel? I am running B50 (50%bioD/50%diesel). I imagine this will displace the need for ashless 2 stroke oil?

While we're on the subject of bioD. . .how about some thoughts on the effects this fuel might have on the IP in general?

thanks.

[gmctd]

I have not used Bio, but a number of threads and posts on that subject are available for the searching, here - you may find sufficient info amongst those.

[6.5 Detroit Diesel]

I have the injection pump off of a 1993 6.2 one ton. This is a DB2829 4979. This is the same pump as the one I found in a 1983 6.2 one ton truck. Should be the same as yours if you are wondering what your numbers are.

[bbbear]

Good question -

Heard of a stainless steel .357 Magnum, but not a DB2 - anyone else?

The only aluminum inner part is the inside of the aluminum main housing and cover - else is steel but for the electricals, fuel oil keeps it from rusting.

Ashless two-stroke motor oil is formulated for combustion chamber service, leaves no residue(s) - Diesel fuel is a light oil, so they combine well.

ATF has stuff in there to keep seals soft, keep clutch bonding-cement from deterioration, protect the electrical harness insulation and the plastics in the solenoids, and keep the coil wiring from oxidation - woodja want that stuff in yer Injection Pump?

Well, maybe, cause it's got all that stuff in it, also - seals, plastic, insulation, solenoids, wires, etc.

But the IP seal compounds are formulated for Diesel fuel, not automatic transmission service.

And ATF is not formulated for combustion - 2-stroke oil is.

ATF is not formulated to lubricate a 1700psi injection pump - 2-stroke oil has no formulation to damage that pump, and will burn with no residue.

Try it - you'll like it.................

Thank you for the very useful info!

[bbbear]

I have the injection pump off of a 1993 6.2 one ton. This is a DB2829 4979. This is the same pump as the one I found in a 1983 6.2 one ton truck. Should be the same as yours if you are wondering what your numbers are.

Thanks for the info. Years ago we owned a Datsun pickup, ( ugh, gasser! ) but this is our first American truck. I'm in the early GMC learning stage so it'll take awhile to absorb all of this. I knew it was a 3/4 ton LL4 engine, but only last night discovered that it's the NA, IDI, 270 Hp, heavy duty J class. After I've learned a bit more about trucks, particularly this model, I'll once again call the original owner for clarification.

[DmaxMaverick]

......I knew it was a 3/4 ton LL4 engine, but only last night discovered that it's the NA, IDI, 270 Hp, heavy duty J class......

270 HP?? High performance builders strive to get close to that, with turbo, drugs, bells/whistles, etc.

The 6.2/6.5 N/A's are in the 130-160 HP range.

[gmctd]

Maybe that's Canadian HP, eh?

[Mr. Bone]

Thanks for the numbers on the IP. . .very helpful indeed! Cheers

[DmaxMaverick]

Maybe that's Canadian HP, eh?

Hmmmmm. What's the conversion rate, eh?

[bbbear]

270 HP?? High performance builders strive to get close to that, with turbo, drugs, bells/whistles, etc.

The 6.2/6.5 N/A's are in the 130-160 HP range.

OOPS! You're right. I mis-read that! Thanks for the heads up!

[bbbear]

I have the injection pump off of a 1993 6.2 one ton. This is a DB2829 4979. This is the same pump as the one I found in a 1983 6.2 one ton truck. Should be the same as yours if you are wondering what your numbers are.

It's probably rather hard to carry on a dialogue with the likes of me, since in the GMC diesel truck area, I'm the equilvalant of a kindergartener, while you're probably the equivalent to a college grad.. That said, according to an article, "The GM 6.2L Diesel Engine," by Jim Bigley, the 1986-88 Heavy Duty version which, as I understand it is the J series, engine#LL4, the fuel injection pump is a DB2-4544.