OM606 engine wobble - PeachParts Mercedes-Benz Forum

spock505 · #1 09-04-2018, 01:46 PM

You misunderstand, it's not about measuring but performing the same visual tasks as you would pop testing - lets see if all six match each other, if one is a bit out of sorts that could be suspect.

Most of pop testing is visual, checking chatter, spray pattern and so on - i know the injectors are good so any variance is pump side.

Thinking about it, this is a lot quicker than pulling all six holders, no priming either - just plug and play.

I have a small pipe bender for the job.

Diseasel300 · #2 09-04-2018, 01:57 PM

Quote:

Originally Posted by spock505

You misunderstand, it's not about measuring but performing the same visual tasks as you would pop testing - lets see if all six match each other, if one is a bit out of sorts that could be suspect.

Most of pop testing is visual, checking chatter, spray pattern and so on - i know the injectors are good so any variance is pump side.

My previous point still remains valid. If the injectors test good on the bench and have good pop and spray patterns, they'll do the same on the engine. If the IP develops enough pressure to pop them, it's going to be the same pattern they did on the bench. There is nothing in the IP that will affect pop pressure or pattern.

If the IP is ruined enough internally to be causing a dead-skip at idle, it should be easily identified by simply cracking the injector lines one at a time and finding the one that makes no difference.

If the IP is marginal on one cylinder, cracking the lines one at a time and finding the cylinder that makes the least amount of difference will identify the cylinder that needs further investigation pretty quickly.

dieselbenz1 · #3 09-04-2018, 02:33 PM

Quote:

Originally Posted by spock505

You misunderstand, it's not about measuring but performing the same visual tasks as you would pop testing - lets see if all six match each other, if one is a bit out of sorts that could be suspect.

Most of pop testing is visual, checking chatter, spray pattern and so on - i know the injectors are good so any variance is pump side.

Thinking about it, this is a lot quicker than pulling all six holders, no priming either - just plug and play.

I have a small pipe bender for the job.

Make certain to take a video and post it should you go ahead with this.

spock505 · #4 09-07-2018, 06:10 PM

Couple of developments to report, firstly sent off pump serial number to listing above for compete match - need to order...perhaps..

As mentioned during summer month run 100% of veg oil which provides better lube and smoother operation, given this decided to add 500ml of alcohol per 60 litre of veg - cheap skate diesel purge idea ?

Without claiming a complete success, each journey is an improvement on the last, something to watch.

spock505 · #5 11-01-2018, 05:19 PM

Weather in upper part of hemisphere is starting to get chilly, earlier altitude sensor adjustments may have been a worked okay on tick-over but proved problematic when starting.

Anyhooo..reversed changes increasing fuel to air ratio (choke) - this device is fitted to compensate for high altitude where air density deceases/increases.

The purpose of my post is to ask whether this mechanism adds a 'dampening' effect similar to the old SU type carburetors?

There's no doubt it makes a difference to injector performance, just not sure exactly how.

spock505 · #6 03-28-2019, 03:45 PM

Few bits and bobs ordered ready for pump overhaul, one thing to point out is this relates to pumps fitted to OM603. 5 and 6's which don't have torqued nozzle holders.

I point this out as there is much misinformation stemming from earlier pumps requiring more detailed calibration, just because someone made a YouTube video don't mean it's correct

spock505 · #7 03-30-2019, 07:16 AM

Hopefully located the source of problem but likely need couple of small parts, return springs and so on -

Anyone point me in the direction of manual for M series Bosch pump, MW is available online for earlier models but not the latter M type.

Thanks,

spock505 · #8 04-08-2019, 04:17 PM

Vac pump gasket due to arrive tomorrow, hopefully crack-on pulling the injection pump for rebuild.

On a related subject, I was amazed at how much influence the ADA had on gear shifts. During adjustment to the lean side shifts went back to hard, opening up (CCW) reverse - this would explain what has happened in the past given how out of sync everything remained at time of purchase.

Some ham fisted mechanic had bent the ADA to one side in order to access a glow plug, this then presumably threw out shift changes prompting mechanic to adjust everything else - I came along adding to the woes by adjusting modulator to compensate, pretty sure everything is back within spec (give or take) including a straightened ADA.

Below diagram show the intricate relationship to other pump components including 'bump stop' which directly effects tick over smoothness (amongst other things).