STD Tuning Engine Need help to solve om617a nailing...

Need help to solve om617a nailing...

Need help to solve om617a nailing...

 
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bryant.cw
Naturally-aspirated

17
07-02-2012, 06:18 AM #1
I have swapped in an om617a into my W460 G wagen. The first motor I swapped in had horrendous nailing, low power, and bad blow by. I sourced another motor and dropped it in.

It runs much better, has compression around 340-360 in all cylinders, less blow by, much less smoke from the exhaust, more power etc. Feeling better about this engine.

However, I still have nailing in 2 of the cylinders. Not tragically bad, but I can't stand it. Just grates at my nerves, not to mention it causes the engine to shake and really rattle the whole car.

I have adjusted and cleaned alda and fittings, stretched the fuel bypass spring, adjusted IP timing with millivolt method, run diesel purge, adjusted the valves, new fuel filters, new fuel lines, diesel is clean and fresh, new lift pump and primer pump, no air in the bypass line as far as I can tell, cam timing is -3 degrees (which makes no sense, but considering that mercedes allows up to +8 degrees of chain stretch, I don't think a few degrees off should matter much), 'rebuilt injectors' with monark nozzles but I can't really verify for myself they are in spec.

What should I check next?
bryant.cw
07-02-2012, 06:18 AM #1

I have swapped in an om617a into my W460 G wagen. The first motor I swapped in had horrendous nailing, low power, and bad blow by. I sourced another motor and dropped it in.

It runs much better, has compression around 340-360 in all cylinders, less blow by, much less smoke from the exhaust, more power etc. Feeling better about this engine.

However, I still have nailing in 2 of the cylinders. Not tragically bad, but I can't stand it. Just grates at my nerves, not to mention it causes the engine to shake and really rattle the whole car.

I have adjusted and cleaned alda and fittings, stretched the fuel bypass spring, adjusted IP timing with millivolt method, run diesel purge, adjusted the valves, new fuel filters, new fuel lines, diesel is clean and fresh, new lift pump and primer pump, no air in the bypass line as far as I can tell, cam timing is -3 degrees (which makes no sense, but considering that mercedes allows up to +8 degrees of chain stretch, I don't think a few degrees off should matter much), 'rebuilt injectors' with monark nozzles but I can't really verify for myself they are in spec.

What should I check next?

JustPassinThru
W123 and W124

491
07-02-2012, 09:12 AM #2
(07-02-2012, 06:18 AM)bryant.cw ...I have...'rebuilt injectors' with monark nozzles but I can't really verify for myself they are in spec.

What should I check next?

You just answered your own question. Buy the pop tester and shims kit from mercedessource.com, pull the injectors, disassemble them and clean thoroughly (I use Hoppe's #9 gun-cleaning liquid in an ultrasonic jewelry-cleaning machine) (also, do not mix parts from the injectors; clean them one at a time), then set the injectors to pop at precisely 131 bar = 1926 psi. Hand-file one shim if you need to (finishing with # 0000 steel wool --I wrapped a bit of this around a Dremel bit (well, actually, a variable-speed Proxxon, which is the German Dremel)-- and a thorough rinse with carb-cleaning spray to elimininate metal particles), to get the pop pressure at a dead-exact 131 on all five. I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

Or, just ship them off to Greazzer and have him do it, see this thread:

http://www.superturbodiesel.com/std/thread-3745.html

Greazzer uses a different cleaning solvent, and he does not use any abrasives. I presume he has a better shims kit than I do.
This post was last modified: 07-02-2012, 02:34 PM by JustPassinThru.

Gone but not forgotten: two W123 sedans and two W124 wagons.
W124 1987 300TD wagon, for sale, $1000 (some assembly required).
JustPassinThru
07-02-2012, 09:12 AM #2

(07-02-2012, 06:18 AM)bryant.cw ...I have...'rebuilt injectors' with monark nozzles but I can't really verify for myself they are in spec.

What should I check next?

You just answered your own question. Buy the pop tester and shims kit from mercedessource.com, pull the injectors, disassemble them and clean thoroughly (I use Hoppe's #9 gun-cleaning liquid in an ultrasonic jewelry-cleaning machine) (also, do not mix parts from the injectors; clean them one at a time), then set the injectors to pop at precisely 131 bar = 1926 psi. Hand-file one shim if you need to (finishing with # 0000 steel wool --I wrapped a bit of this around a Dremel bit (well, actually, a variable-speed Proxxon, which is the German Dremel)-- and a thorough rinse with carb-cleaning spray to elimininate metal particles), to get the pop pressure at a dead-exact 131 on all five. I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

Or, just ship them off to Greazzer and have him do it, see this thread:

http://www.superturbodiesel.com/std/thread-3745.html

Greazzer uses a different cleaning solvent, and he does not use any abrasives. I presume he has a better shims kit than I do.


Gone but not forgotten: two W123 sedans and two W124 wagons.
W124 1987 300TD wagon, for sale, $1000 (some assembly required).

sassparilla_kid
diesel > all other fuels

1,618
07-02-2012, 09:53 PM #3
(07-02-2012, 09:12 AM)JustPassinThru I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

I need to see this, since I am leery of even setting a starbucks coffee on my car while its running sometimes

-1982 300D Turbo, 280k miles, ALDA apparently maxxed, fram 8038, 12 lbs boost, non-egr manifolds, W/M injection, 4 brake light mod, Gen II w126 front rotors/calipers, 4-speed swap
In the works: A/W IC, adjust pump, turbo rebuild (w/60 trim comp wheel)
-1980 300SD, 110k, project car. Goal is to get it lookin' like it did on the showroom floor (body and interior wise, not necessarily under the hood )
-1974 240D, FRESH PAINT!!!!!!
sassparilla_kid
07-02-2012, 09:53 PM #3

(07-02-2012, 09:12 AM)JustPassinThru I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

I need to see this, since I am leery of even setting a starbucks coffee on my car while its running sometimes


-1982 300D Turbo, 280k miles, ALDA apparently maxxed, fram 8038, 12 lbs boost, non-egr manifolds, W/M injection, 4 brake light mod, Gen II w126 front rotors/calipers, 4-speed swap
In the works: A/W IC, adjust pump, turbo rebuild (w/60 trim comp wheel)
-1980 300SD, 110k, project car. Goal is to get it lookin' like it did on the showroom floor (body and interior wise, not necessarily under the hood )
-1974 240D, FRESH PAINT!!!!!!

bryant.cw
Naturally-aspirated

17
07-05-2012, 05:38 AM #4
Vid or it didn't happen!

That sounds good, I have more pressing stuff to do at the moment, but I think I will do what you suggested. Might build my own pop tester just for the hell of it. As it stands, some times it nails, sometimes it doesn't as much, I've had to take a look at my project, a look at my wallet, and learn to get a handle on my expectations. C'est la vie.

Thanks for the advice, but you really should get a video of the nickel on the valve cover!
bryant.cw
07-05-2012, 05:38 AM #4

Vid or it didn't happen!

That sounds good, I have more pressing stuff to do at the moment, but I think I will do what you suggested. Might build my own pop tester just for the hell of it. As it stands, some times it nails, sometimes it doesn't as much, I've had to take a look at my project, a look at my wallet, and learn to get a handle on my expectations. C'est la vie.

Thanks for the advice, but you really should get a video of the nickel on the valve cover!

Simpler=Better
PORTED HEAD

2,127
07-05-2012, 10:59 AM #5
(07-02-2012, 09:53 PM)sassparilla_kid
(07-02-2012, 09:12 AM)JustPassinThru I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

I need to see this, since I am leery of even setting a starbucks coffee on my car while its running sometimes

Balanced injectors make an enormous difference. Check one of my videos in my build, with shot nozzles, a stretched chain, on a stand it's still pretty smooth.

Newbie-read this: Cheap Tricks
617.952-220k-Getting built up
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Simpler=Better
07-05-2012, 10:59 AM #5

(07-02-2012, 09:53 PM)sassparilla_kid
(07-02-2012, 09:12 AM)JustPassinThru I did this to mine when I installed the mercedessource Monark 261 nozzles and can, at idle, balance a nickel on the valve cover.

I need to see this, since I am leery of even setting a starbucks coffee on my car while its running sometimes

Balanced injectors make an enormous difference. Check one of my videos in my build, with shot nozzles, a stretched chain, on a stand it's still pretty smooth.


Newbie-read this: Cheap Tricks
617.952-220k-Getting built up
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?

bryant.cw
Naturally-aspirated

17
07-08-2012, 04:20 AM #6
Yargh, no money to procure or make pop tester. Anybody wanna rent theirs out? Sigh, living in alaska would probably make any rental + both ways shipping almost as expensive as making one. Not to mention you've got me wanting to get an ultrasonic cleaner now! I am wanting to make a fairly large one capable of doing brake calipers, cylinders, starter etc etc.

Perhaps some amount of nailing is acceptable, or at least tolerable without feeling you are going to cause damage?
This post was last modified: 07-08-2012, 04:21 AM by bryant.cw.
bryant.cw
07-08-2012, 04:20 AM #6

Yargh, no money to procure or make pop tester. Anybody wanna rent theirs out? Sigh, living in alaska would probably make any rental + both ways shipping almost as expensive as making one. Not to mention you've got me wanting to get an ultrasonic cleaner now! I am wanting to make a fairly large one capable of doing brake calipers, cylinders, starter etc etc.

Perhaps some amount of nailing is acceptable, or at least tolerable without feeling you are going to cause damage?

JustPassinThru
W123 and W124

491
07-08-2012, 09:33 AM #7
Greazzer's fee is very modest. I suggest you PM him.

Gone but not forgotten: two W123 sedans and two W124 wagons.
W124 1987 300TD wagon, for sale, $1000 (some assembly required).
JustPassinThru
07-08-2012, 09:33 AM #7

Greazzer's fee is very modest. I suggest you PM him.


Gone but not forgotten: two W123 sedans and two W124 wagons.
W124 1987 300TD wagon, for sale, $1000 (some assembly required).

 
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