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6.5 Diesel Injector Rebuild

My injectors tested out at around 2000 psi. give or take a bit. If I'm going to 18:1 compression pistons and planning to put in the injectors to run for the next 100,000 miles (I'm not planning to test different pressures - I don't have the time or patience), should I have them bumped up to 2300? 2800?

@Rockabillyrat tested for me and will be doing the work.
 
SnowDrift said:
My injectors tested out at around 2000 psi. give or take a bit. If I'm going to 18:1 compression pistons and planning to put in the injectors to run for the next 100,000 miles (I'm not planning to test different pressures - I don't have the time or patience), should I have them bumped up to 2300? 2800?

@Rockabillyrat tested for me and will be doing the work.
Click to expand...

It depends on what injecton pump you plan to run. Your injectors at 2000psi are fine for stock or even a tuned DS4/turned up DB2 (4911). If you are planning to run a built DB2 or a DS4831-6033 (beast pump) then i would step up the pop pressure a little.
 
Well I figured I would dig this thread back up since I have started playing with some injectors. I also have to give @MrMarty51 and @Big T a shout out for helping me make this happen and get going on this.

I know Big T and Will still wants to know about those old marine units, I have not messed with them yet, not until I can reliably get better at this.

After taking a couple injectors apart that were gummed up, nozzles stuck together, and full of varnish. I tossed them into an ultrasonic cleaner with some water base degreaser at about 140 degrees for 30 minutes. all the parts came out very clean, the housing looked like it had been sand blasted and the inner parts were shiny and clean.

I put them back together and tried testing them but their spray pattern was not that great. I'm wanting to figure out if the nozzles can be saved yet. Not sure if I can lap the pintle in the nozzle. I've been searching online for more information on this but not finding much at all.

I did try messing with one that seems to spray decent but not sure if I have the technique right on the tester. pumping it like I would using a bottle jack they seem to chatter at a lower pressure than if I pump slowly. a slow pump and they will "leak" or piss at higher pressure, but after chatting with another fellow member, I have the technique just need to work on pressures more closely.

I found some shims on the jungle site that measure 6mm ID x12mm OD I want to see if they will fit into the housing. taking the ID measurements I got 12.2mm. if not the next size available I found was 10mm OD. Being the actual shims are 11.5mm OD we shall see.

also got a hand full of 5mm flat washers from work that are roughly 1mm thick which I can sand on a flat surface to possibly stack and achieve the total shim thickness when using the thin ones. From what I have read online folks are using shims to adjust, then measuring the total and are going back in with washers sanded down to the same amount in order to save on some of the shims that are hard to get.

as of right now I have one that I have been playing with to get the right pressures also to learn on the technique pumping on the tester.

I did a short video of the one I've been working on, right now it seems to be popping off but has a pressure range as I am stroking the pump. Note that with this now shimmed to about 2.06mm thick if I slowly pump the tester, pressure will climb up over 2500psi before it "leaks" I believe it needs to have another small shim added yet.

Here are some pics and a video. On the pintle, take note of the discolored area and a flat spot on the very tip. Both injectors I have pulled apart have this same flat area, not sure if this is from wear or how they are made.

Please chime in with your knowledge :)

IMG_5740.jpg
IMG_5746.jpg
IMG_5747.jpg
IMG_5743.jpg

 
dbrannon79 said:
Well I figured I would dig this thread back up since I have started playing with some injectors. I also have to give @MrMarty51 and @Big T a shout out for helping me make this happen and get going on this.

I know Big T and Will still wants to know about those old marine units, I have not messed with them yet, not until I can reliably get better at this.

After taking a couple injectors apart that were gummed up, nozzles stuck together, and full of varnish. I tossed them into an ultrasonic cleaner with some water base degreaser at about 140 degrees for 30 minutes. all the parts came out very clean, the housing looked like it had been sand blasted and the inner parts were shiny and clean.

I put them back together and tried testing them but their spray pattern was not that great. I'm wanting to figure out if the nozzles can be saved yet. Not sure if I can lap the pintle in the nozzle. I've been searching online for more information on this but not finding much at all.

I did try messing with one that seems to spray decent but not sure if I have the technique right on the tester. pumping it like I would using a bottle jack they seem to chatter at a lower pressure than if I pump slowly. a slow pump and they will "leak" or piss at higher pressure, but after chatting with another fellow member, I have the technique just need to work on pressures more closely.

I found some shims on the jungle site that measure 6mm ID x12mm OD I want to see if they will fit into the housing. taking the ID measurements I got 12.2mm. if not the next size available I found was 10mm OD. Being the actual shims are 11.5mm OD we shall see.

also got a hand full of 5mm flat washers from work that are roughly 1mm thick which I can sand on a flat surface to possibly stack and achieve the total shim thickness when using the thin ones. From what I have read online folks are using shims to adjust, then measuring the total and are going back in with washers sanded down to the same amount in order to save on some of the shims that are hard to get.

as of right now I have one that I have been playing with to get the right pressures also to learn on the technique pumping on the tester.

I did a short video of the one I've been working on, right now it seems to be popping off but has a pressure range as I am stroking the pump. Note that with this now shimmed to about 2.06mm thick if I slowly pump the tester, pressure will climb up over 2500psi before it "leaks" I believe it needs to have another small shim added yet.

Here are some pics and a video. On the pintle, take note of the discolored area and a flat spot on the very tip. Both injectors I have pulled apart have this same flat area, not sure if this is from wear or how they are made.

Please chime in with your knowledge :)

View attachment 91245
View attachment 91243
View attachment 91246
View attachment 91244

Click to expand...
God bless you for trying on this. Those Bosch Marine injectors were well worn. I can say based on feel there was a bit more power with the Marine, but also a lot more black smoke. The power increase was not huge, but you could feel the difference. For me it was not worth the trade off of increased smoke as that is essentially dirty power. My mileage has increased 1.5 mpg with the stock Bosch inhectors.
 
I hope that You can come out of this with at least one set of good injectors.
There is a set of mighty old Lucas injectors.
I am not sure if those are for heads from an older 6.2 or if they are from a 6.5.
I believe also that those must be some original German Bosch units and I hope the nozzles are in good condition.
 
The nozzle without a tip on it is a marine nozzle. Most of the nozzles I pulled apart were very worn with a groove worn into it where it seals. I did buy some diamond paste to try and lap them but never found any I deemed good enough to bother with.
 
ak diesel driver said:
The nozzle without a tip on it is a marine nozzle. Most of the nozzles I pulled apart were very worn with a groove worn into it where it seals. I did buy some diamond paste to try and lap them but never found any I deemed good enough to bother with.
Click to expand...
You wouldn't happen to have any photos on the grove wear? I think I need to get me one of those magnifying light up units that clamp to the bench to help me see the tips better.
 
I know new genuine Bosch India nozzles seem to be rare now to find. I was searching around on the jungle site and ran across this chineese nozzle.

I know china made ones are not to be trusted, but for the price I am curious if we could find a somewhat decent replacement to do a trial run on.

Maybe the worn out engine in my 93 can be a prime candidate to test some in though I don't put a lot of miles on it. I do have an hour meter in the dash. maybe I can trial some once I get better at this.

Here is t he link on the ones I found.

https://www.amazon.com/dp/B07H95GHG3

I did look up these further and they are coming from China and are priced directly on their site at $3.50 I think it was each with a 10ea minimum order.

Thinking out loud, if the cheap nozzles last say 30k miles, for my use case that would be about two years of use. I wonder about trial running at maybe a year and see how they wear. Not sure if anyone has done this on cheaper nozzles.
 
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This evening I did a little more tinkering with two injectors. One that was full of varnish I had cleaned up and another that is a low mileage injector.

I wanted to get everyone's input here as for the pressures they are working at along with spray pattern. the video doesn't show well on the spray pattern since I took it with my phone. I also took the video in slow motion trying to catch every detail I could. behind each injector I inserted two still images of where it started to spray (note the solid stream) and when it went full spray. Still not sure if ether one can be called "good enough" to run or not. Nor do I understand what to go off from on saying "this is what pressure it's set at" since there seems to be a range of when it starts to when it stops. Both injectors continue to spray all the way up to 2000 psi when the tester handle runs out of stroke. Maybe someone can chime in on how I should be taking the reading and understanding when it needs more or less shimming. It's all a learning process for me here.

 
Oh, and one other unknown for me. what is the knob on the side of the tester used for? I ended up somehow blowing out the o-ring on the shaft of the knob. scrounged around and found one to replace it with, but all I can tell is once the pump has been pressured up, you can turn this knob in and watch the gauge climb little by little until the injector begins to leak or the knob stops. I have been keeping it almost fully backed out hoping not to blow out another o-ring.
 
Hopefully if the weather allows this weekend I plan to clean up my little work bench and re-mount the tester so it doesn't move so much when in use. I think that will help a lot to watch the gauge stabilizing the tester. My bench is made up from some 2x4's and 1/4" plywood. Not the greatest!
 
I forgot to look around the work bench and on the floor to see if there was some kind of a seal that may have dislodged from the gauge stem when I had to remove the gauge to get it to fit in the box.
I will try to remember to dooh dat in duh morning.
 
I would like to add some info for others that want to know. I had ordered some shims off the jungle site that are 6mmx12mm and I can confirm that they do fit into the injector body. they come in a pack with 4 different sizes. I did measure them to see if the thickness and diameter is accurate. Thickness is exact but they measure 11.8mm diameter. They will work with our injectors.

https://www.amazon.com/dp/B0BT5PM3ZC

1734533862589.png
 
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Well this afternoon I played some more with a couple of injectors. These both were lower mileage ones and I noticed that both had no markings on the nozzles so I am assuming they are chineesium nozzles. one thing I noticed is on these pintles there were no flat spots in the tips like there are on the Bosch ones.

after reading through the DP thread and it's links showing how to lap the cone washer and the body. I used a square of ceramic flat tile I had which seemed very flat against my straight edge ruler, glued two strips of sand paper 500 and 800, then used diesel as a lubricant for lapping.

ran everything through the ultrasonic cleaner with a mixture of ZEP 505 cleaner and water at about 140 degrees for 30 minutes. that seems to take all the carbon, dirt and rust off the injectors. Lapped all the surfaces, cleaned up once more with brake cleaner and compressed air.

Then when testing I ended up having to add almost a full 1mm worth of shims to get them up to popping around 1800-1900 psi. total shim thickness including the spacer washer they already had was 2.80mm on both. Then I took out the shims and replaced them with a m5 flat washer that I had lapped the stamped edges from which then matched the 1mm worth of shims.

I thought that was interesting that I had to add that much more thickness to get them up to snuff. reading pressures on the tester is kinda hard seeing as the needle moves quite fast for my eyes trying to watch when it sprays and seeing the pressure. I did also learn from reading that it takes short quick blasts and I can get about three short blasts in a single stroke of the tester lever.

moving forward I need to find some small thicker flat washers that I can replace the shims with once I figure out what thickness each injector needs. this will help save on using up all the shims as they are rebuilt.

I also determined that most of the older injectors I have that are all varnished up will need new nozzles. I think maybe next week I might try ordering a set I found on the jungle site for $36 and see how they work. the thread I was reading showed one guy used those chineesium nozzles for over a year and seemed to have good luck. with all these parts getting harder to find, it will be about who reproduces them at the best quality. I might even try reaching out to Mercedessource and see if they can source a replacement. I found out they are making their own for the Mercedes now.
 
One other thread talked about lapping the nozzles and pintle. most cases they said the chatter stopped after lapping. I have some hard sticks of jewelers rouge in different grits. Found another site that talked about heating some olive oil and making a paste from the rouge. I might try this and use to lap the old junky nozzles and see if I can bring them back to chattering and spraying mist rather than them pissing a steam like they are now. time will tell, it can't get any worse on the old nozzles LOL. The two I finished up with today are spraying and chattering fine but they are made in China!
 
Funny thing is that everyone of these old varnished up injectors I have pulled apart all just have a single thick washer in them as the shim. none actually any shims in them. not sure if this is how they are put together when new and then not pressure tested but just for chattering. the ones I have cleaned up I have been just putting back together as they came apart and testing. they all seem to spray at around 1000-1200 psi! This is making me think they were never checked before leaving the factory when new!

Has anyone else noticed this?
 
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