Stuck Injectors - Any Advice? - PeachParts Mercedes-Benz Forum

Squabble · #1 08-22-2009, 05:18 PM

83 300D

i was well on my way to replacing my injector nozzles when i got to the actual removal of the injectors. they will NOT budge! the whole engine moves i'm pulling so hard but nothing is happening.

can i spray some pb blaster around them? do i just need to get a bigger breaker bar and yank at it some more? i need to be cautious of catastrophe but i also have limited time to get this done this weekend.

is it safe to assume, because of how hard this is, that i will definitely be needing a vise to take the injectors apart? i was hoping to just use two wrenches as i don't have a vise...

79Mercy · #2 08-22-2009, 05:26 PM

A 27mm deep socket and a ratchet should break them loose, the injectors on my 300D weren't hard to get off at all.

Squabble · #3 08-22-2009, 05:41 PM

Quote:

Originally Posted by 79Mercy

A 27mm deep socket and a ratchet should break them loose

that's what i thought but it's just not happening. also, the last two injectors, nearest to the firewall, don't fit correctly into my deep socket. i haven't gotten there yet as i was starting with the first one but i just checked them all and found that little tidbit.

AND...how the heck do you fit the deep socket on the third one? the throttle linkage/stop lever thing is completely in the way and the socket goes over the top crooked and will not sit on the injector correctly.

what gives? help!

GWNorris3rd · #4 08-22-2009, 06:54 PM

Use a breaker bar it will not need much force as compared to a ratchet. I know mine were impossible with the ratchet, but a breeze with the breaker bar! Just remember to use new heat shields (crush washers) when installing the injectors and torque to 70-80 Nm or 55-60 ft-lbs.

mespe · #5 08-22-2009, 06:55 PM

Make room in there. linkage is easy to remove and reinstall.
Make sure you put the socket on Squarely, otherwise you'll ruin a bypass fitting. Socket probably doesn't fit on because you're working around obstacles and the fuel bypass has some hose on it,,, good luck

TMAllison · #6 08-22-2009, 07:11 PM

Its going to be tough to get them apart without a vise to hold them firmly. I'd give the first one you get out a try before removing the rest.......

New nozzles is only half the job; the second half is pop testing and adjusting the pop pressures.

Squabble · #7 08-22-2009, 07:39 PM

well, i gave up for the night. i've got a farmer friend with a better garage and tools, i'll head over there tomorrow to finish this job up.

something else funny occurred though:

i put the injector lines back on, i put the return lines back on, i re-attached the vacuum lines i had to disconnect, and then went to start it up. it wouldn't turn over, obviously because of the air in the lines, so i gave it a good 40 or 50 pumps on the primer. started up but ran roughly and noisily. i floored it and the biggest, blackest cloud of smoke my car has ever emitted came gushing out the exhaust. just thick soot all over my driveway and through the air. i did it a couple more times and got even more. i took it for a quick spin, brought it up to temp and came back. parked it, floored it, and got a lot of smoke, not as much but still a lot. is this normal behavior for the lines being disconnected? did i hand pump too much fuel into the system or something? did i do something yanking on the injectors?

either way, thanks for the advice. i'll get cranking on them tomorrow. still though, does anyone know if it's a good idea or not to spray pb blaster or another lubricant in there to help out?

EDIT: the local diesel shop/tractor trailer shop to me, when i asked them about pop testing new injectors, that is was b.s. and that any company worth anything does all that before hand. they claimed to be in business for X amount of years and never did any pop testing before installing new injectors. food for thought?

Diesel911 · #8 08-22-2009, 09:15 PM

I am going to post some pics with this.
1st pic a good deep socket for removing the Injectors should be Deep all the way up till the last 1/2 inch or so of the length of the socket. The one in the blurry pic is from Sears and I have used it on Injectors since 1975 (it is 1-1/16 inch).

The next to pics are how to take apart your Injectors without a vice.
The Socket you removed the Injector with and Breaker Bar go on the Injector Nut end and a 22mm or 7/8 open end of the a Combination Wrench goes on the upper body of the Injector with the Flats on it.
In the position it is in in the pic I woud push down on the Breaker Bar handel to loosen the Injector Nut.

When you tighten the Injector Nuts you substitute a Torque Wrench for the Breaker Bar.

Diesel911 · #9 08-22-2009, 09:49 PM

This is how I deal with a tight Injector. (Use 1/2 inch drive stuff; 3/8 drive will be too flexiable.)
Steady with your Right hand and keeping you Left Arm Straight bend back and pull back with your Shoulder in a quick smooth (do not jerk it) move; you can even take a short step back if you need to.

Also, pumping on the hand primer will not bleed/clear the air out from between the Fuel Injection Pump and the Injectors.

To do this you tighten down the Injector Hard Line Nuts by hand and turn them back to loosen them alittle. Afterwhich you crank the Engine you till you see Fuel coming out from under all of the Injector Hard Line Nuts.
After that tighten the Hard Line nuts and start your Engine.

Also it is very easy to get dirt in the Injectors.

Squabble · #10 08-22-2009, 10:09 PM

WOW! Thank you!

i'll get back at it. i was using a 3/8 with an adapter up to 1/2 for the 1 1/6 socket. no more of that i guess.

this info is great! i really appreciate it!

djustin973 · #11 08-23-2009, 12:03 AM

To respond to your shop's comment. They're right, any set of new injectors from a reputable company will be pop-tested and adjusted, but you're not installing new injectors. You're installing new nozzles in your old injectors, if they've NEVER pop-tested injectors then they've never rebuilt a set, only installed new ones. The parts that actually effect pop pressure (The spring and shims) aren't being replaced in your case. If you only install the new nozzles without pop-testing your injectors you've only done half the job.

TMAllison · #12 08-23-2009, 12:05 AM

Quote:

Originally Posted by Squabble

EDIT: the local diesel shop/tractor trailer shop to me, when i asked them about pop testing new injectors, that is was b.s. and that any company worth anything does all that before hand. they claimed to be in business for X amount of years and never did any pop testing before installing new injectors. food for thought?

Reading between the lines......They install "factory rebuilt" injectors only as they dont have the tools to do nozzle replacements like you are wanting to do.

Some folks do it your way and get away with it; others do so and create more problems for themselves.

Brandon_SLC · #13 08-23-2009, 02:28 AM

Excuse my ignorance if I'm missing something, but wouldn't soaking them overnight with some penetrating oil help? If I ran into the same problem, I think I'd warm up the engine then use penetrating oil and let it sit.

Isn't there a risk of striping threads? I've done that once removing a seized spark plug from an aluminum block engine, and have been paranoid ever since. I use a lot of anti-seize these days.

Maybe it's not an issue with a cast iron block.

Squabble · #14 08-23-2009, 08:53 AM

that is the last question i have for everyone. i too am nervous about stripped threads and am curious about this.

Quote:

Originally Posted by Brandon_SLC

Excuse my ignorance if I'm missing something, but wouldn't soaking them overnight with some penetrating oil help? If I ran into the same problem, I think I'd warm up the engine then use penetrating oil and let it sit.

Isn't there a risk of striping threads? I've done that once removing a seized spark plug from an aluminum block engine, and have been paranoid ever since. I use a lot of anti-seize these days.

Maybe it's not an issue with a cast iron block.

Brian Carlton · #15 08-23-2009, 11:48 AM

Quote:

Originally Posted by Squabble

that is the last question i have for everyone. i too am nervous about stripped threads and am curious about this.

Almost impossible to strip the threads on a cast iron head.

You can use some PB Blaster overnight........then just apply force with an 18" breaker bar........they will release.