STD Tuning Engine engine stumble at 2700 RPM

engine stumble at 2700 RPM

engine stumble at 2700 RPM

 
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Torkey
Dirty Diesel

220
01-10-2015, 01:32 PM #1
I'm having an issue with the engine stumbling when at 2700 RPM. Seems to run fine at faster and slower RPMs. When the engine stumbles there is a puff of white smoke that comes out of the tailpipe which smells like fuel and not oil.

I've checked all of the injectors and the spray pattern is good and the pop pressure is balanced.

I've also checked the cylinder compression and they are all at 405 psi +/- 10psi.

I'm wondering if this might be a problem with the injection pump but really don't know what else to check at this point.

79 300CD
82 300SD
Dirty Little Freaks Racing
Torkey
01-10-2015, 01:32 PM #1

I'm having an issue with the engine stumbling when at 2700 RPM. Seems to run fine at faster and slower RPMs. When the engine stumbles there is a puff of white smoke that comes out of the tailpipe which smells like fuel and not oil.

I've checked all of the injectors and the spray pattern is good and the pop pressure is balanced.

I've also checked the cylinder compression and they are all at 405 psi +/- 10psi.

I'm wondering if this might be a problem with the injection pump but really don't know what else to check at this point.


79 300CD
82 300SD
Dirty Little Freaks Racing

F.R.A.S
Holset

579
01-10-2015, 02:40 PM #2
It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).

F-tune Performance [Image: V-band_om606.jpg] [Image: GTX3582R.jpg] [Image: gs6-53dz_gearbox.jpg]

I can help you out with all your manual transmission, clutch, flywheel, intake and exhaust manifold issues.
F.R.A.S
01-10-2015, 02:40 PM #2

It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).


F-tune Performance [Image: V-band_om606.jpg] [Image: GTX3582R.jpg] [Image: gs6-53dz_gearbox.jpg]

I can help you out with all your manual transmission, clutch, flywheel, intake and exhaust manifold issues.

Torkey
Dirty Diesel

220
01-10-2015, 02:44 PM #3
(01-10-2015, 02:40 PM)F.R.A.S It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).

It is an OM617 engine. Is it possible to replace the plungers without having to pull the IP to have it put on a calibration machine? I've got 3 of these pumps laying around. I could try swapping out the plungers to see if it helps. That is assuming there is little risk in doing it.
This post was last modified: 01-10-2015, 08:00 PM by Torkey.

79 300CD
82 300SD
Dirty Little Freaks Racing
Torkey
01-10-2015, 02:44 PM #3

(01-10-2015, 02:40 PM)F.R.A.S It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).

It is an OM617 engine. Is it possible to replace the plungers without having to pull the IP to have it put on a calibration machine? I've got 3 of these pumps laying around. I could try swapping out the plungers to see if it helps. That is assuming there is little risk in doing it.


79 300CD
82 300SD
Dirty Little Freaks Racing

[486]
TA 0301

57
01-11-2015, 12:25 AM #4
pump's gotta be completely disassembled to swap elements
[486]
01-11-2015, 12:25 AM #4

pump's gotta be completely disassembled to swap elements

Volker407
naturally aspirated

157
01-11-2015, 08:16 AM #5
(01-10-2015, 01:32 PM)Torkey I'm having an issue with the engine stumbling when at 2700 RPM. Seems to run fine at faster and slower RPMs. When the engine stumbles there is a puff of white smoke that comes out of the tailpipe which smells like fuel and not oil.
....
I'm wondering if this might be a problem with the injection pump but really don't know what else to check at this point.

I also could imagine the pump governor to be stuck at 2700rpm for some reason.
Did you change governor settings?
Try to drain the oil / rinse the governor housing of the pump to get the dirt out.

Check timing chain guides and chain tensioner. Maybe something is worn (mileage?) and the timing chain is in resonance at 2700rpm, swinging around and messing up your timing.

You can also try to turn the pump completely towards engine block (=earlier injection) to see if it happens earlier or later then.

Try to drive one fuel tank with 10% 2stroke oil
or 30% refined rapeseed oil (not cold-pressed!) added to your diesel tank.
If that mixture changes behavior something with direct contact to fuel has a problem.

Always test one change at a time.

Gruß
Volker
Volker407
01-11-2015, 08:16 AM #5

(01-10-2015, 01:32 PM)Torkey I'm having an issue with the engine stumbling when at 2700 RPM. Seems to run fine at faster and slower RPMs. When the engine stumbles there is a puff of white smoke that comes out of the tailpipe which smells like fuel and not oil.
....
I'm wondering if this might be a problem with the injection pump but really don't know what else to check at this point.

I also could imagine the pump governor to be stuck at 2700rpm for some reason.
Did you change governor settings?
Try to drain the oil / rinse the governor housing of the pump to get the dirt out.

Check timing chain guides and chain tensioner. Maybe something is worn (mileage?) and the timing chain is in resonance at 2700rpm, swinging around and messing up your timing.

You can also try to turn the pump completely towards engine block (=earlier injection) to see if it happens earlier or later then.

Try to drive one fuel tank with 10% 2stroke oil
or 30% refined rapeseed oil (not cold-pressed!) added to your diesel tank.
If that mixture changes behavior something with direct contact to fuel has a problem.

Always test one change at a time.

Gruß
Volker

Petar
7.5mm M pump

459
01-11-2015, 08:17 AM #6
(01-10-2015, 02:44 PM)Torkey
(01-10-2015, 02:40 PM)F.R.A.S It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).

It is an OM617 engine. Is it possible to replace the plungers without having to pull the IP to have it put on a calibration machine? I've got 3 of these pumps laying around. I could try swapping out the plungers to see if it helps. That is assuming there is little risk in doing it.

Why don't you try swapping the pump with a spare one ??
Petar
01-11-2015, 08:17 AM #6

(01-10-2015, 02:44 PM)Torkey
(01-10-2015, 02:40 PM)F.R.A.S It's the om617 we're talking about right? Mr Dieselmeken have to correct me if wrong but I believe that if a plunger (pump element) is worn in a place this can happen. 2700rpm might be an area where the plunger gets most worn (highway speed maybe, without knowing your gearing).

It is an OM617 engine. Is it possible to replace the plungers without having to pull the IP to have it put on a calibration machine? I've got 3 of these pumps laying around. I could try swapping out the plungers to see if it helps. That is assuming there is little risk in doing it.

Why don't you try swapping the pump with a spare one ??

Torkey
Dirty Diesel

220
02-11-2015, 02:44 PM #7
Finally got around to swapping the IP.  The stumble is gone.  Thanks again to OM616 for his awesome write up on IP adjustments.

79 300CD
82 300SD
Dirty Little Freaks Racing
Torkey
02-11-2015, 02:44 PM #7

Finally got around to swapping the IP.  The stumble is gone.  Thanks again to OM616 for his awesome write up on IP adjustments.


79 300CD
82 300SD
Dirty Little Freaks Racing

 
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