Detroit diesel 12v71TI no power out of the hole

Hi,


I want to share with you the observations I have been seeing after I went into the water from the 60 days on the hard at Cay Marine.

Changes from before the yard are as follows:
1. Brand new bottom with no bumps or growth.
2. 3 bladed Props now instead of the 4.
3 . Side Exhaust now instead of the straight back.

The initial sea trial was great. Boat planned ok .. a little longer than with 4 blades but not much more. Economy was way up. Burned the fewest total to Bimini ever. On that trip I had some clamps give on the starboard engine. 2 where on the water side of an air cooler and 2 where on the water outlet of the fuel cooler. The prior was causing water to spray right at the airsep of the port engine which caused salt to get into the turbo. The latter was just causing water to leak into engine room.

After this situation happened, I notice 2 days later when coming back from Bahamas that boat was having a harder time planning. I thought it was perhaps the airsep that had gotten clogged on the port and this was reducing the ports power. When I got back to the dock and checked it a few days latter the Turbo on the inside bank of the port was stuck. I sprayed pb blaster on it and was able to unstick it and left it spinning freely.

I then ran boat a couple of more times the hard to plane problem was still there. What I noticed on the rpm gauges is both motors spin easy up to 1200 rpms, the port continues to climb and puts out black smoke when I am trying to push it. The starboard does not. I move it to WOT and its almost like RPMS(starboard) drop momentarily. There is minimal black smoke coming out of the starboard. Eventually when Port Engine reaches 1650, the boat starts to plane, and at this time that's when the Starboard engine RPM begins to rise beyond 1250 rpms. Eventually the Starboard meets the Port and boat is doing 22knots at 1850 with ease. There is a light trace of black smoke from the starboard but nothing more than before. Fuel was relatively clean, but bowls has some black algae so I cleaned them after the trip but saw not difference.

When I got back from Memorial day I had extensive fuel contamination problem. I bought bad fuel in between Island trips. I then fixed this for the Charter this past weekend and did not affect the problem at all. Boat took the longest time to get on plane leaving the Yacht Club(4-5 mins). Also, now I am starting to see significantly more black smoke at cruise out of the Starboard Engine.


Turbo on the starboard spin freely and are relatively new.. Less than 300 hrs or about 1.5 years old. Air boxes were done about 2 years ago on that engine.

We don't know how many hours that engine has, but the last oil sample said it was worse than the port. Yet, the starboard clearly had more life before this problem.

Another important note on fuel consumption. Out of the hole with both engines at WOT, port reads 44gph and starboard reads 15gph. Then at cruise at 1850 Port reads 35 gph and Starboard 38. Starboard is about 20% higher than it usually was.

What do you guys think?

It seems like either fuel is not getting there when it needs it, or perhaps some injectors are shot.

Thoughts?

Turbo is on the port side which is engine that is running fine.

It is still spinning freely .

The problem was there before fuel contamination. So I actually took apart racor a twice and on the second go around I replace secondary filters as well.

One thing I found last night that I forgot to mention was that the air stop flaps on the bad engine were not 100% open. I would say it was 90% only.

I will run boat tomorrow and report findings.


Thanks

The port engine is running fine. I agree turbo getting stuck is a potential problem but has nothing to do with Starboard engine not going past 1200 rpm under load.

I cleaned all air filters and inspected Air Box of the turbo that got salt into it. It looked good.

As far as your situation, the black smoke from your riser leak simply gets sucked back into the engine, I would expect minimal smoke in the engine room at cruise.

Thanks Ron...

I will know later today when I try to run her...

Engine that ingested salt water through airsep is the port side. Engine that is not responding is the Starboard side.

I ran the boat a over the weekend and Problem with the starboard engine is still there. A very slight improvement was seen but still taking too long to get on plane. Starboard Engine RPMS just don't show up till the ports gets the boat on plane. Also fuel consumption on the Starboard is up 20% according to Flowscan.

Where do I place the tap for the boost Gauges? Would that be at the Blower? Or at the Air Boxes?

What should the boost pressure be ?

And What should the Fuel Pressure be?

Thanks!

Is the Fuel Pressure reading at idle at 1500 or under load?

Thanks Jimbo!

Ozzy

I have not tested yet. Will report back tonight.

Thanks

Didn't connect Fuel Gauge yet, however yesterday I ran both engines at WOT at the dock.

Port : 2668 RPMS
Starboard: 2442 RPMS

Also, I have a Glendenning Synchronizer in which the PORT is the Master and Starboard is the slave.

Also I verified that Throttle linkage has full travel.

Since Starboard has ~200 rpms less, can this mean not enough fuel? Or perhaps a broken injector tip?

I checked the water for Fuel Sheen and saw nothing.

Thanks!

Fuel Filters, Primary and Secondary are all new. Racor bowls were cleaned and free of dead algae. Fuel in Bowl is crystal Clear.

Have not looked at the Vacuum pressure on my Racor Gauges. Will keep this in mind.

I don't have a spare pump. If its gear driven, how can it operate partially?