Can´t get my port engine to spool up between 1000 and 2000 RPM under load

Steve500dancer

Steve500dancer

Member
Jul 13, 2009
868
Franklin Tennessee (Nashville area)
Boat Info
1996 500 sundancer
2001 340 sundancer sold
2001 270 Rinker sold
1996 240 sundancer sold
Engines
Twin 6v92 Detroit deisels
I posted this on Boat Diesel.com but I thought I would post it here also

I have a 96 Searay Sundancer with 6v92sTAs. The port motor was rebuilt a couple of seasons ago and I have probably only put 100 hours on it since then. This weekend was the first weekend I ran it up over 1000 RPM and I had to wait about 50% longer for the port motor to spool up and catch up with the starboard engine. Eventually it catches up and all is fine. I also can´t use my engine sync without the port motor smoking till it spools up.

At the beginning of the season I replaced the Racors, (Grayish color) and the fuel water Seperators along with an oil change. I did not clean or replace my Stewart Stevenson air filters. I also didn´t clean out the glass bowl on the Racors.

Is it possible the filter is clogged up or I am not getting enough fuel pressure? I have not cleaned my filters since the rebuild and most of the time is spent at about 1000-1500 RPM.

Also trying to figure out the best way to clean the washable filters. I have heard that just blowing them out is enough and I also heard that spraying them with carb cleaner and and letting them dry is good.

Thanks in advance
Steve Bone
 
Since it eventually catches up and smokes while it's getting there, doesn't it sound more like a turbo/air issue than lack of fuel?
 
This isn't fuel related or a dirty fuel filter if t he engine eventually runs up to rpms. It sounds more like a turbo problem where the turbo is restricted or the gate isn't opening enough to allow adequate air in the intake. That explains the heavy smoke until rpms build. You are dumping fuel in the engine but there isn't enough air to completely burn it off.

Call your Detroit guy...........a boat might be a welcomed change of pace. He's probably tired of working on tour busses this week.
 
fwebster said:
This isn't fuel related or a dirty fuel filter if t he engine eventually runs up to rpms. It sounds more like a turbo problem where the turbo is restricted or the gate isn't opening enough to allow adequate air in the intake. That explains the heavy smoke until rpms build. You are dumping fuel in the engine but there isn't enough air to completely burn it off.


Call your Detroit guy...........a boat might be a welcomed change of pace. He's probably tired of working on tour busses this week.
Click to expand...

Well my Detroit guy is on vacation somewhere in the Appalachian Mountains hiking. Hopefully he is not squealing like a pig listening to banjo music.

Frank, is it possible that it could be an air filter restriction? I personally haven't cleaned my filters since I bought the boat.

Another thing that I just thought about is an issue I had last year with engine sync on the port motor that I had someone look at and they adjusted some piece of linkage that was not very tight. I did check to make sure that it was tight but maybe it is not working properly. I will attach a picture with an arrow.

3fe51c02399c83739738769b1a38d7a6.jpg


Thanks
Steve


Sent from my iPad using Tapatalk
 
Whether the current issues is related to air filter cleanliness or not, it wouldn't hurt to clean them since you never have. K&N makes a filter cleaning kit comprised of a cleaning solution and spray oil and they are available at most auto parts stores - especially those that sell K&N filters. I seem to recall the kit is about $15.00 and should provide enough product for four individual cleanings.
 
The red flag that pretty much rules out fuel and intake air flow is the fact that the engines eventually run up to full RPM's. That points at the turbo system that isn't letting the engine develop the boost needed to spool up so it is acting like a normally aspirated engine with a big fan that isn't turning in the intake system.

Clean filters are always a good thing, however, unless you have a shedding Labrador retriever in the bilge, it isn't likely that the little dust you would have accumulated would cause the current problem.

Unless the synchronizer clutch is slipping internally to the extent that the engine isn't getting full throttle but eventually does, the symptoms don't point at the synchronizer. Rule out the synchronizer by running the boat with it off.
 
When a turbo is bad enough, you can tell just by spinning it by hand. Might be worth a shot before the mechanic clock starts ticking...?
 
Pull your air filter and and inspect for side to side movement of the shaft. Also, take a flashlight and look at the edges of the turbine and interior of the housing to see if there has been any contact. Also check for any signs of oil coming from the front seal of the turbo while you are in there.
 
Are you using the syncs when throttling up, if so I would agree with Frank, clutch is probably slipping in the sync system.
 
No I have not used my engine synk at all this year. I was also told that it could be gummed up from sitting all winter.

I am going to the boat tonight and pulling off the air filters. I will get in as close as I can and get a bunch of pictures and post them. Hopefully this doesn't turn out to be a 4th of July disaster.

Thanks fellas
 
If it is a turbo, it is a fairly straight forward repair. Changing one out is about a 2 hr job. You can opt to have it rebuilt or purchase a reman from a Detroit dealer or reputable dealer.
 
I was just told by a Deisel mechanic that works on all of the heavy equipment at our development that the first thing I need to do is lube up the waste gate and work it back and fourth. I am counting on the turbo being bad considering it was the only thing that I didn't replace when I had the inframe done. Oh well hopefully $1000.00 or close to it will get me out of this one.

Steve
 
There is a turbo rebuilder in West Virginia that has your turbos around $400.00. I don't know his name, but I can find out tomorrow.
 
Well tonight I went to the boat and removed the air filters and spun the turbo. The turbo shaft had almost no play in it front to back and side to side. It also spun freely and continued to spin when I let go. I inspected all the hoses and clamps to see if I was loosing boost from a clamp and everything looked good. I couldn't find any spots where it looked like it has been leaking air from. I did not find a waste gate and could not see any rods coming from the turbo that would indicate that it had a waste gate anywhere near the turbo.

I am attaching a video I took along with some pictures
https://vimeo.com/130505649
cd014079bded3fd8ad5ca0a2f8c95d8c.jpg

a901acff28c7c83e3ab78a10e4d06ad0.jpg

77c0fc31a0bda88f69c695ea42ce169c.jpg

ff46a0eef42a4192188542464aa8f74f.jpg

88746c39d2ea6edc1ecc13e660d8bc07.jpg



Sent from my iPad using Tapatalk
 
i took a good look at the filters on Friday and noticed that they were not in very good shape, especially the one on the port motor. They are showing signs of age with some areas that are completely see through as well some areas around the top that rubber that were torn a frayed. I tried to find new filters and man was that fun considering they were K&N filters and the numbers on them did not match up with anything that K&N showed. Turned out they were made for Walker air/sep by K&N. They are also now made by Racor and more readily available. I will be ordering two new ones today. I will probably replace the inner filters as well.
I did swap the port and the starboard filters out on Saturday and ran the boat. No black smoke and she spooled up a lot quicker then it did last weekend. I actually videod the engines and the gauges so I could post it. However, the damn go pro was on upside down mode. I just have to figure out how to swap it to right side up and I can post it.

I wonder if my issue could be air filters or the fact that I have not run it very hard this season so far and she is a bit gummed up?

Steve
 
Those might be the prettiest 20-year old turbos I've ever seen. Are you sure your rebuilders didn't touch them?

In contrast, those filters don't look happy...
 
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