Aneriod Adjustment?

[lpmcc]

I have a pair of ’99 6CTA’s with 2,400 hours.  I’ve owned the boat for 13 years and these engines have been great.  But, on takeoff, the srtb engine shows some black smoke and needs a little more throttle than port to get the turbo to kick in.  It has always done this.  Once on plane, all good.  Just when getting on plane does this happen.

I remember a “lazy Aneroid” discussion here, and thought this might be the cause of my issue?  I’ve searched the forum, but did not find it.  I did find the instructions on how to make the aneroid adjustment, but before I do that, I thought I’d ask here for comments. Thanks 

Topic

[David Estes]

Figured it out

Finally figured it.

Turbo – leaking oil and sent out to Turbo Dave for new cartridge – result – brought boost up 10 lbs

Turbo pipe gasket leaking after rebuild – found that and got a little more boost going where it was supposed to go.

Rebuilt fuel pump was in the equation also – after confirming boost was back up, had to adjust the AFC a few more clicks to get it just right.

Results – engines spool evenly and start to come alive in the 1600-1700 range.   EGT’s are back down on the stbd engine to match port side.

[Tony Athens]

Injection Pump Aneroid

Basically the aneroid limits the fuel to limit or control excessive black smoke in relation to boost pressure, especially during acceleration..  If you have black smoke you typically do not have an aneroid iuse.. If the engine engine will not accelerate or lags,  and you have dark smoke, it’s usually related to too much prop and the operator is in denial... 

 

Do your 6CTA’s reach an accurate 2700 RPM under fully loaded vessel conditions and reach it easily?

[lpmcc]

Got it, thanks.  I must have misunderstood what the aneroid does.  Can you explain what it does and its purpose?

Thanks!

[JimmyK]

No problem, but reading your original post, if you have black smoke while the engine’s trying to spool up, you DO NOT have a lazy aneroid, and reducing aneroid preload is going to do nothing more than give you more black smoke.  You’re barking up the wrong tree IMO.

1 user thanked author for this post.

Tony Athens

[lpmcc]

Thanks Jmmy!  Great info.  I have those bits coming to me, but if they don’t work, I will do as you suggest.

Thanks again!

[JimmyK]

There is torx, and there is also torx plus.  There are also 5 and 6 point versions of each, then there is also the tamper proof variant (same as security).  You have to get them all right.

What Dan posts is a hex or allen drive, totally different, doesn’t apply.  Torx also is not metric or standard.

The screw you’re trying to take off is a tamper proof 5 point torx plus drive, size 25.

With that said, every time I’ve tried, I just shear the tip of the bit off.  That screw is usually on there pretty good and the hole in the middle of the bit (tamper proof feature) makes the bit really weak.  I just grind flats on the screw and remove with vice grips.  It isn’t holding anything on anyway, just there so you don’t ‘accidentally’ adjust the aneroid preload.

[lpmcc]

Thanks Dan,

I’m using “Torx Security” bits (a TT7 – TT40 set.  TT20 & tt25 are the closest).  Is that difference than “Tamper Resistant” in your link?

Thanks for the help.

[Dan]

Are you using metric tamper proof tork bits? They are very tight.

http://www.amazon.com/ATD-Tools-13795-Tamper-Resistant-Metric/dp/B0771J3GXW?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A2DZ2V7B8TRIYM

 

[lpmcc]

Tony & Cory (and anyone else),

I tried to follow your instructions on removing the aneroid cap.  It appears to be a tamper proof Torx head, but I bought a set of assorted bits (all kinds), but cannot find one that fits.  Attached is a pic <sorry, it’s the best I could take>.  And ideas on what size this is or how to remove?

Thanks

Larry

[David Estes]

No worries.  Black smoke = fuel/air is fuel heavy.   My turbo issue could be just a chance catch as well since I’m not getting the black smoke – I just have reduced power.   In rebuilding the pump and then having low power, we went fuel heavy to see if that would spool the turbo up, but all it did was belch like an 892 Detroit.

If you do make an adjustment to the aneroid and it improves your issue, please keep me in mind.

[lpmcc]

Thanks for the comments.  I don’t think it is the turbo (but it could be).  It has always done this, and I have had the exhaust off a few times to ck turbo & exhaust and both were fine (no oil, no water, blades good, spin good, little carbor, etc.)

[David Estes]

Following – but, also may have somewhere for you to look -check your turbo –

I am having a similar issue, but no smoke on takeoff.  Recently rebuilt fuel pump due to the “low load” shake rattle and roll issue between 800-1000 rpms.  Once pump rebuilt and boat sat for a bit, could not get stbd engine to spool up – but still no smoke.   Found moisture valve on bottom of aftercooler hanging open and per quick call SB, we put a plug in the hole instead of the value (known to cause issue)   Did a quick retest and engine had a little more power, but not enough to get up.

Retested with mechanics on board and tested engines together by increased rpm by 100 at a time to get boost, egt’s, etc readings and document results.  Stbd maxed out at 1500 rpm with throttle wide open and other engine at 1500 rpms.  However, if I advanced the throttle on the port side about 2-300, the stbd would follow suit and wind up at 2650 max rpm.  However, boost was still low by about 10 lbs on stbd at WOT.

Found oil behind the turbo in the exhaust and diagnosed low boost – found oil in the wrong places on the turbo cartridge – exhaust side.

Turbo is out for rebuild now –  will update with results in about 2 weeks.

[Author]

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