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New or rebuilt injectors

SnowDrift

SnowDrift

Ultra Conservative. ULTRA!
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It is sounding like I am faced with the decision to buy a new set of injectors or have mine rebuilt. Bosch nozzles have been recommended and there is still debate on what pressure to run. I'm currently using a DS4 pump but my hope and plan is to eventually get to a DB2 pump. If I go with new, is there a recommended supplier where the parts are not some chinese imported knock-off? I have a vendor or two in mind but wanted to hear what the consensus is as of today.
 
jrsavoie said:
Whatever you install. Make sure they're tested and balanced.
I heard John Faddis sells them tested and balanced. I don't know if that's true or not
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He did have those on his web store but I have not seen them in a while.
Might send them an email and see if they would work up a set for You.
If they will not then buy a set of their, or Leroy Diesel new injectors and get them tested and bLanced before installing them.
Maybe @dbrannon79 is now set up well enough to do the job. If not then send me a PM and I’ll give You the number and addy of a shop near me that does an excellent job.
I had Joe do the injectors I had removed from my old engine and now there is not one puff of smoke on the coldest start ups.
 
I can test and adjust them. have a bunch of shims too. I'm still in the learning process playing with these old used ones. if someone would like me to set some up I wouldn't charge anything, it would be free for any of yall :)
 
dbrannon79 said:
I can test and adjust them. have a bunch of shims too. I'm still in the learning process playing with these old used ones. if someone would like me to set some up I wouldn't charge anything, it would be free for any of yall :)
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Thats mighty generous of You Doug.
Just dont ever let something such as this eat up Your family time.
 
My vote is go new. Caveat is that the source has to produce known good units. Not bashing any of the outstanding rebuilders, but will once again offer that I have gotten bit by even the good ones. New (known good) has yet to let me down.

Check with Leroy as his site still lists new injectors.

For pressure, my vote is to go with the standard pop. Am sure that others might offer different perspectives.

Whatever you do, do not go with marines. I was not happy with them. Got no difference in fuel mileage or power (as measured by the pants-meter). The marines belched at startup. The OE injectors let the engine rev more freely.
 
JayTheCPA said:
My vote is go new. Caveat is that the source has to produce known good units. Not bashing any of the outstanding rebuilders, but will once again offer that I have gotten bit by even the good ones. New (known good) has yet to let me down.

Check with Leroy as his site still lists new injectors.

For pressure, my vote is to go with the standard pop. Am sure that others might offer different perspectives.

Whatever you do, do not go with marines. I was not happy with them. Got no difference in fuel mileage or power (as measured by the pants-meter). The marines belched at startup. The OE injectors let the engine rev more freely.
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Anymore, I wouldn't install any set of injectors that hadn't been tested and balanced
Most sets that I hear of that have been tested need at least one injector fixed
 
JayTheCPA said:
My vote is go new. Caveat is that the source has to produce known good units. Not bashing any of the outstanding rebuilders, but will once again offer that I have gotten bit by even the good ones. New (known good) has yet to let me down.

Check with Leroy as his site still lists new injectors.

For pressure, my vote is to go with the standard pop. Am sure that others might offer different perspectives.

Whatever you do, do not go with marines. I was not happy with them. Got no difference in fuel mileage or power (as measured by the pants-meter). The marines belched at startup. The OE injectors let the engine rev more freely.
Click to expand...
Anymore new vs rebuilt is toss up. As too pressure- its like anything else:
Stock will work. Taking the time to learn what pressure is best with your set up makes it better. But how much time & $$ is if you can affordably learn to diy.
And as Marty said- this is exactly the kinda thing that will eat up time.

One lone truck makes it hard to justify. A couple of them makes sense because you build 2 sets 100psi away from each other and test in each truck. Swap in a set& test out for 0-60, hiway towing power, mpg then in goes the next set. 100psi up. Over and over agin until you know what is good for your set up.

When done if one truck like mine- I have a spare set to go in 100,000 miles later. Pull the others & full cleanup & reset.

I believe some of the power and mpg these engines had is lost due to the new fuel. From making diy fuel I learned different viscosity was a real thing even when btu, flashpoint, gel was the same. It changes the atomization and that is MASSIVE.

Atomize to quick and you loose on the full piston stroke being under power but have more total power thats choppy between cylinders so you loose mpg and peak numbers in the higher rpm band.

Atomize too low and you smoke easier, especially at start up. Easy to burn excess fuel without power gains. This is what I think happened when you ran your marines. Running them needs to fit your application. If you aren’t over 75% throttle often then marines are mistake. Running above 75% throttle often means you’re set up & drive style is demanding more fuel most the time. Now there is a CHANCE they help. Tiny gm turbo and a lot of city driving especially not towing and they are still wrong. Hx35 or bigger, towing, high rpm like hummer/hmmwv kn freeway (wind load similar to gmt400 towing a 2 axle camp trailer): then what happens is this (example not actual numbers),
at 1,000 rpm the marines are fueling as if you are at 1300 rpm
1750 rpm marines are acting like 2,000 rpm this is where they begin to help
2.300 rpm they act like you are at 2,500 rpm
At 2,600 rpm they act like 2,750 rpm.
The higher rpm the ip looses output per stroke. It can’t fill the chambers as fast is the basic understanding. So the MARINES put out more fuel per stroke but do so allow the timing flatter on idle and accurate at your desired rpm- and in a boat that is in the 3800 rpm area.
Starting an old diesel and having some have from fuel to ignore is part of it when your focus is high rpm gains.
But doing this- getting them adjusted to YOUR EXACT engine is a must. How you want the reaction and performance and at what rpm range - injectors putting out more fuel per stroke is gonna move around a lot with different turbos, uses, etc.
you have to tune it to your use or you see none of the benifits.

When a guy has two trucks he can easier justify the time involved because mpg gains are doubled. Not waiting 100,000 miles to use the second set doesn’t have to happen - they both go in right away. And if a guy has say one with an ATT and the other a gm5, he will surely learn two different pop settings work differently. So he gains advantages differently.

We all know we can trust Leroy is selling real stuff. But he can’t control manufacturing errors and changes. I know I am chicken little always expecting the sky to fall. But to me having new ones from him tested is a wise investment.

Anyone jumping to marines is making a big mistake not tuning the pressure to your engine. You can do it with one set but it’s more annoying to drive & record- remove injectors, putting in the yellow caps and spend a day diy resetting. Hopefully installed the next day … maybe next weekend if you are having them done. Then go fill up the tank and start the testing over. Two sets means one day to swap and the truck is on the road. Then the next day maybe you get the 8 that came out readjusted, maybe only get 2 done then it’s dinner time. Two more a couple days later, 1 more the next day and so forth fitting them in as time allows.

Now it’s been a week and your day off is coming- you recorded data each day while driving and that day off they get swapped.

Eventually you see falling number and go backwards by 25 psi, 25 psi, and you learn this truck with this exact set up and this driver with his uses - X,XXX psi is the best.
I can tell you from racing the 6.5 before getting crazy with nitro propane:
Tuning the injectors to your set up can be 40-50 hp differnce and 5 mpg gains.
And most of the set ups I did - peak torque gains fell right in line with peak mpg gains. So having your truck that doesn’t tow a lot often, but you want to be a hyper miler, it still applies. But the day you swap turbos- those peak number can change by a couple hundred psi.

remember folks- all marines do is push more fuel in at every revolution. I will be running them and I will not loose mpg- but remember I am the guy who literally leaves the stoplight and the foot hits the floor. If speed limit is 55 then WOT to 55 and let off until cruising at 60 mph. Johnny law next to me? WOT until 50 then ease up till at 55mph.

I have driven dragsters, motorcycles over 150 mph. A 6.5 diesel is never an exhibition of power. If I didn’t spin the wheels I wasn’t showing off or racing. A short video to the judge how my diesel can ruin a set of tires in minutes and when the testimony of the cop says no the tires never spun- means I never was convicted. One actually tried in my hummer. When I showed the judge 0-60 stock is over 20 seconds and takes a full quarter mile, i said “I show off by looking cool and going slow like a low rider guy. This officer is just jealous.” The judge and everyone else laughed (except the cop). I followed up with “your honor, I would have to have lower to exhibit it and this slowest ever rig since the cars of the Great Depression simply doesn’t have it. No tire smoking video made for that court day obviously. Haha
 
Agree 100%. any injector you buy whether it's new or rebuilt needs to be pressure checked. iirc Marty ran into this with the new ones he bought. he had to send them off to have them checked after seeing them in his tester the pressures were way off.

in my fooling around with old crusty gummy used injectors, all that I have seen is them needing to be cleaned out and shimmed up to get pressures up to par. as they go through heat cycles over time the spring looses it's tension lowering the pop pressure. as for the spray pattern, after they were pulled apart and ran through a ultrasonic cleaner, the spray pattern came back to life. I'm sure others have run into injectors that were just fubar from springs going bad or the nozzles getting torched from running longer than they should, but then again if a nozzle gets torched, so did the piston too!
 
I haven't gotten a chance or put enough time into it yet, but have been wanting to pull the injectors out of the 93 and check their pressures. the DB2 IP was turned up by the PO (how much, IDK) but it does smoke on acceleration and with the onset of the cold weather has been getting harder to start. yes the engine is wore out, but I would like to test them, bring them back up to stock pressure and see if it runs any better.

also will be a decent test on how well a set of used re-pressured injectors will do once I get the chance to pull the engine in an effort to try and rebuild or replace it when that time comes.
 
A ruined tip of injector doesn’t mean piston is bad. In the right (or this case wrong) circumstances it can damage a piston. It is the precursor often. BUt simple carbon can plug injectors.

Imo step one on a rig with over 75,000 is unbolt muffler, kitty, etc and giver it the wmi treatment of water down the intake to clean away the carbon. This cleans it off the pistons, valves,glow plug, turbonium. Put her back together and test run that. Now you have a nice starting place. Then remove injectors and check pressures & patterns. Remember that going up in pressure ever so slightly delays the injection timing. How much you deal with in a ds4: like IceCube said I ain't the one.

On db pumps I played with moving timing and pop pressures at same time. Created chaos and no clear results. I found easy to trend gains by setting normal timing then leaving it. Learn pop pressure for your situation. Then play with timing.
If you had a full time race crew dedicated to every last hp & peak mpg in theory you could learn leak timing with each injector setting. But unless you are single and bored out of your skull- I wouldn’t. Bigger gains are made by 1 more psi boost.
 
dbrannon79 said:
Agree 100%. any injector you buy whether it's new or rebuilt needs to be pressure checked. iirc Marty ran into this with the new ones he bought. he had to send them off to have them checked after seeing them in his tester the pressures were way off.

in my fooling around with old crusty gummy used injectors, all that I have seen is them needing to be cleaned out and shimmed up to get pressures up to par. as they go through heat cycles over time the spring looses it's tension lowering the pop pressure. as for the spray pattern, after they were pulled apart and ran through a ultrasonic cleaner, the spray pattern came back to life. I'm sure others have run into injectors that were just fubar from springs going bad or the nozzles getting torched from running longer than they should, but then again if a nozzle gets torched, so did the piston too!
Click to expand...

Some of the new injector problems is likely due to an era poor quality from Bosch India production. Reportedly it got so bad that AM GEP forced a "come to Jesus meeting" with Bosch Germany and Bosch India and the quality problems have since been reduced. I know that I installed new Bosch India years ago. Smoke cleaned up and the truck rain great until my oil cooler line failure. While changing the engines, I had Paveltolz test the injectors with Bill Heath and 6 of the 8 tested bad. I ordered new Bosch Indian injectors and threw those in, as I had no time to test. They've been working fine. Hoping that that Bosch India did clean up their quality control.
 
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Maybe @Rockabillyrat or someone with lots of experience can chime on on what things to look out for on how they wear out other than spring tension/shimming for pressures. maybe even some pics too! I need to invest into one of those lighted magnifying glass desk lamps so I can take a closer look at the needle tips and whatnot. I know the injectors for our rigs are becoming a rare bird compared to all the newer ones out there, but even the mercedes guys might be able to tell us how and what to look for. those injectors are a very similar design.
 
Big T said:
Some of the new injector problems is likely due to an era poor quality from Bosch India production. Reportedly it got so bad that AM GEP forced a "come to Jesus meeting" with Bosch Germany and Bosch India and the quality problems have since been reduced. I know that I installed new Bosch India years ago. Smoke cleaned up and the truck rain great until my oil cooler line failure. While changing the engines, I had Paveltolz test the injectors with Bill Heath and 6 of the 8 tested bad. I ordered new Bosch Indian injectors and threw those in, as I had no time to test. They've been working fine. Hoping that that Bosch India did clean up their quality control.
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Sometimes the failings aren't incredibly noticeable.
 
Big T said:
Well the injectors are in and I’ve put about 2,300 miles on them. I don’t have the time to pull them and have them tested. Not with all the other work I have on my plate.
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This is a huge part of why I say the two set method.
You have two rigs that run the 6.5- buying a new set now & learn to do it in whatever down time you get. 1/2 hour here, 45minutes there. 10 hours into it, you can swap in the set and truck never has down time. Little by little you learn the best pop setting for the two trucks, not just one.

First time set at say 2000 psi and go into the 94. Get the mpg & 0-60. Rebuild the ones from the 94 in mean time to 2100. Then pull the 2100 set and put them in the 99. Now rebuild the 99 set to 2200 as you can. Get 0-60 mph & mpg in both trucks during normal use. The 2200 goes intk the 94, the 2100 coming out of 94 goes into 99. Keep the circle going.
You’ll learn within a year easy what each differently set up truck wants.

I never seen this done and people not gain 1.5 -2 mpg. Unless the engine wa flat worn out. Even then still saw 1mpg. You have to decide if the mpg gains and smoother running engine adding to engine life is worth it. Balanced is not a easily figured amount of added miles but our testing in the 90’s said roughly 5% injectors and 10% if entire engine balanced but that is starting from brand new and that was based on 4 trucks left stock, 4 injectors only, 8 fully balanced- all ran similar routes, similar miles per year. Percentage is me rounding off to dedicate to memory. And the fully balanced includes perfect bearing & ring gap not just mass production.
 
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