Howdy folks, I usually send all my injectors to a local shop to get rebuilt. I have no problem giving them the International / Ford powerstroke injectors and the like - those are a real PITA. But, I want to start rebuilding my own mechanical injectors like Delphi and such. Actually, I don't know any more such, so we'll just say Delphi I know I need a tester like this one: https://goo.gl/2WUSyt and probably an ultrasonic cleaner, something like this: https://goo.gl/xkJPT9 And a source for parts like tips, shims, gaskets etc. Other than that, what else do I need? Those injectors seem like such a simple device, I think I should be able to take care of em in-house. I would be happy to hear anyone's thoughts on it. Thank you!
There are some injectors that you can do.. but.. 80% of them have a pressure plate in them w/ small roll pins that align the fuel holes.. IF the tip isn't held against the body using a special teardown & rebuild rig, you end up breaking the pins off & then your S.O.L.. I've been doing pumps & injectors for 30 years & I wouldn't even suggest trying it.. It just depends on the injector & what "internals" are in it.. THEN, how are u going to get the correct opening pressures?? BUT I know what your sayin.. the place I worked at charged 35.00 EACH to CLEAN & TEST!!! EACH.!!! You bring in a set of 6 & that's 210.00 JUST to tell you, you've got 2 bad injectors.. THEN you have to pay about 100.00 apiece for the 2 rebuilds.. & then they'll talk u into doing ALL 6..
I'm only considering the mechanical injectors, no electronic or even common rail, just the basics. They usually have just a cap, nozzle, pin, spring and a shim. Pressures measured with a pop tester like the one I posted originally, right? What kind of rebuild rig is needed?
If you say so.. SOME mechanical injectors have a spacer plate that MUST BE collapsed/held in position/stationary, before removing the bottom nut.. Just do a search on the type of injector you want to take apart BEFORE taking it apart.. & if u see "a plate" w/ dowel pins in the break down, don't take it apart..
I would suggest a very clean room, dedicated to injection only. Having a power vent system to filter out dust and lint is good too.
So we're clear, I don't know my butt from a hole in the ground here I'm listening to what you're saying. If I'm hearing you right, I'm going about this the wrong way. So, let me take a step back and ask what do I need to rebuild the mechanical injectors? Maybe "rebuild" is not accurate, maybe "service" might be more accurate.
Injectors like this are what I run into the most: https://www.dieselpartsdirect.co.uk...sel-fuel-injector-tjbb02701d-ford-1213938.htm
The ones in your link will definatley break.. The best you could do is, pop test them to see if you have a problem.. The tip has to be held stationary when being disassembled/reassembled.. otherwise they twist internally & shear off the small pins inside..
OH, I see what you're saying! That makes sense, thanks. Is there a special tool to hold them, or just pliers or something with soft jaws?
Yes there is a special tool.. You HAD a "good idea".. its just not feasible.. IF u do a lot of engines, it would be a good idea to get a pop tester to check the condition of them before putting them back in..
IMO, not practical to do your own injectors beyond simple functional testing; e.g. pop tests. Parts? Wholesale non OEM parts. Years past those parts were available to members of ADS. https://diesel.org/page/AboutADS
A pop tester is feasible for someone who owns a lot of equipment or rebuilds a lot of engines.. Its suprising that a lot of equipment dealers don't have 1.. Our Mack dealer didn't even have 1..& they NEVER got ANY REPAIRED either.. They'd just pay 30-35.00 apiece to get them checked & take'm back & get Re-Mack injectors.. {you wanna talk about junk}
I can fabricate a tool to hold that tip, I don't think that would be too hard. I ordered a pop tester. The shop I've been taking the injectors to is about 40 mins away, on a good traffic day. So, a trip out and back to drop off, and a trip out and back to pick up - that's 2.5 hours I could spend being more productive. It even get's more ridiculous if I have to go back for any reason. If this thing can save me one trip ever, it's more or less paid for itself. Come to think of it, I really only need it to test. I can get nozzles, shims and such, but at 200 bucks each, it doesn't really make lots of sense to repair. Most of the time, I took em out because the engine was running poorly, and did a compression test that showed good, and I wanted to know if they even work. Just a go-no-go would save me time I think. I'm a one man operation, so an hour of time saved is a big deal to me. Anyhow, thanks for all your input, I appreciate the help!
Another consideration that you may or may not be aware of; get a container to catch the injected diesel when doing the pop-off. Fuel comes out of the nozzle at a pressure that pierces skin, which leads to blood poisoning. Be safe.
AND maybe use 'real' calibration fluid per SAE standard. https://www.otctools.com/products/calibration-fluid Also visit your' local injection shop and ask to see the 'jig-fixture' they use to hold the type of injector you working on. If allowed take a couple of photos, and make you own own. The local shop established in the 50s, DieselInjectionService owner Frank Ostoich shared his knowledge and helped anyone wanting to learn about injection pumps and injectors. Frank built his own calibration stands and injector fixtures while getting started! http://www.disinjection.com/about-us.html My 1st visit @ Frank's shop was in 1957-58 and last visit 2004-5; over those years free help anytime of the day or night! Pop testers, calibration stands, fixtures; just more tools to gather dust from non use.
I got my tester, and once I fixed all the leaks, it works just fine. It's great to have the ability to finally test these things in-house. I have a question though - at first I used regular diesel to do the pop test, and that works great, no problems. But - when I put in that calibration fluid, I get the right opening pressure, and I see streams coming out of the nozzle, but I don't get that "pop - pop - pop" you're supposed to look for. Is that normal? I got the OTC 208629 calibration fluid.
... and once I'm done with the injector, can I leave that fluid in there, or does it need to get flushed out with diesel? Safe to run a little of that stuff through an engine? Thank you for the help!
Depending on the tip "type" depends on the chatter.. some chatter, some don't.. If they pizz w/ no chatter, they're bad.. If they atomize w/ no chatter, it depends.. Do a leak-down test on them.. hold the pressure at 200psi BELOW spec opening pressure & look for droplets out of the tip.. ANY drops=bad tip. Calibration fluid is GOOD for the injector & engine.. it lubes the inj. & has a higher burn rate.. no need to flush.
Good info. Thanks much!
Ditto pumpguy You want to leave calibration oil in the injectors or fuel pump and test equipment because cal-oils have anti-corrosion inhibitors (rust preventive), anti-wear additives etc. Clean diesel fuel is shot in the dark; to many variables from storage-handling. Check injectors and install. Check injectors and stick on the self; 1yr later diesel fuel gums up the valve-check-tip. Good luck