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TAMD41B idle problem

zetec7

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"Just went on a cruise for a f

"Just went on a cruise for a few days. While waiting for a dock assignment, boat at idle (normally around 650 RPM or so), suddenly idle speed went up to 1100 RPM, oscillating from 1000 to 1200 about once per second. Very hard to dock at 5.5 kts.! Engine runs perfectly above 1200 RPM all the way to full throttle, no problem. All perfectly normal until throttle is returned to idle, then the oscillating starts again. Moving throttle slightly higher than idle smooths it out again, but at higher RPM. Recent (about 10-15 hours engine time, and a couple of fuellings ago) oil, oil filter, both fuel filters, air filter all changed, ran perfect until this. No bubbles/water/sediment in Racor. I've added a high-lubricity diesel fuel treatment, but it didn't help.

Is this possibly an injection pump regulator (governor) problem? Anyone have any ideas? Problem came on very suddenly, hasn't gotten better"
 
Start by disconnecting the thr

Start by disconnecting the throttle cable from the fuel pump and see if that makes any changes.
Then let the fuel return run into a container and check for air-bubbles or lack of return.
 
"Tried those...disconnecting t

"Tried those...disconnecting throttle cable didn't help, clear fuel (no air bubbles) in fuel return line. I've noticed that there is a little bluish-black smoke(like it's running rich?) while it's idling (surging from 1050-1200 RPM). Normally there isn't any noticeable smoke when it's warmed up .

I've been told that there are weighted arms in the governor, one for idle (low speed) and one for high speed (similar to the mechanical advance in a gas engine's distributor). Has anyone heard of these giving problems? The motor only has 650 total hours on it, and the local Volvo-Penta pump repair guy says there's no chance there's anything worn in the pump or governor. Possibly there's a shellac buildup stopping the low-speed governor from operating correctly? Anyone know if this is possible? I've checked with several mechanics in the area, and so far, they only agree there's no air in the system (because it performs perfectly above 1100 rpm) and that the injector pump itself must be okay. Other than that, they have no idea what the problem might be. I'm getting frustrated..."
 
"Bluish smoke might indicate a

"Bluish smoke might indicate an oil-leak into combustion chamber. You might have got a broken valve seal. This might even explain the increase in idle rpm as added oil works like added fuel. Any change in oil-consumption on engine?
Any sign of oil on the air-side of the turbo?
Any sign of pressure in the crank case? (clogged filter)
If not I would have taken all injectors first to a Bosch shop for test, then if still not ok the injection pump."
 
"Well, checked the oil level -

"Well, checked the oil level - nothing has changed at all, so it's not using oil as fuel. I got hold of a VP mechanic, who came down to the boat & looked at it. He disconnected the fuel line & fed FPPF cleaner into it, running the engine so the cleaner filled the pump, injectors, etc., and we left it for 4 days to work. I put it back together today, and it runs great...except at idle. Same problem, same surging. Mechanic figures the pump's going to have to come off and be disassembled and checked for broken balance weight springs, etc. Unfortunately, that apparently is going to cost several thousand dollars. It seems there are no easy answers."
 
"Had the pump removed & sh

"Had the pump removed & shipped to a VP pump specialist. He advises there was water in the fuel (did I mention that just before I had this problem, I had a "mechanic" at a VP shop change all my filters, oil, etc.? Turns out he left a spacer out of my water separator, so water, fuel, etc. bypassed the separator - then I got bad fuel when leaving on my trip, so...water straight to the pump). The pump rebuilder advises the pump can be rebuilt, but the total bill will probably be in the $10,000 range including reinstall. Plus, of course, having my fuel tank drained & cleaned, etc.

Anyone know of a source for used/useable/rebuilt Volvo Penta injection pumps? I've Googled for hours, with zero success..."
 
"Mike,
I might not know how t


"Mike,
I might not know how to overhaul the injector pump, but you can bet I wouldn't be the one paying for the mistake of the mechanic at the other shop.
Ten grand sounds high anyway, I'd get the two shops talking to one another...VP shop to VP shop.

Bob T"
 
"To me it sounds You are taken

"To me it sounds You are taken for a ride. You might get a rebuild or even new for half the price in Europe.
The parts normally 'going bad' is repair kit: 876614 which costs about USD 1500,- in Sweden.
Try this link:
http://www.marinepartseurope.com/sv/volvo-penta-sprangskiss-7745920-23-20526.asp x
You do not need a Volvo Penta 'specialist' to do the job, any Bosch service center would probably be better and cheaper."
 
"Last 41 pump I had done by Bo

"Last 41 pump I had done by Bosch shop in Maryland,USA cost customer $1200.00. Very interesting shop you have there."
 
"My mistake - that cost came f

"My mistake - that cost came from another mechanic, based on buying a new pump, install, clean out the tank, etc. The pump rebuilder advised today that the cost of rebuilding the pump to new spec is $2050. Apparently, the water did enough damage inside that just about all that's left of my original parts is the outer housing.

I contacted my insurance company, and they advise they're going to help me.

Question, though (Morten, maybe you can answer this one -). I obviously have to get the water out of my fuel tank. Removing the tank is not possible, as the builder pretty much hung a fuel tank in the air & built a boat around it. My (good) mechanic is suggesting a method of drilling a small hole in the top of the tank, and using a copper-tube probe to suck the water out of the bottom of the tank, then plug the hole with a fitting. Apparently he does this all the time on commercial boats, and it works well. I'm still assuming that even if we pump out all the water we can reach, there will still be traces left in the tank.

My question is this...when I get water in my fuel at gas stations (gasoline vehicles - this is happening at different fuel companies, different gas stations, different pumps...it's become a bit of a scandal in my area)I've used gas line antifreeze (basically methyl alcohol or ethanol) to allow the water to mix with the fuel & be burned. This works well on gasoline-engines (assuming you're not trying to run a 50/50 mix!). BUT...would this be damaging to a diesel engine (would this boost compression too high?), it's injection pump & injectors??? (I'm also assuming that if this mix makes it past the pump & injectors without problems that it would burn in the engine without problems).

Morten - your thoughts?"
 
"having had both a marina with

"having had both a marina with fuel station and been a mech, I have encountered the most in that area.
If tank may not be removed, take out the fuel gauge sender and use that as 'entrance'. problem might be that the tank has bulk heads inside making it difficult to access all areas. Best is to steam it out, tank in the boat or ashore.
Then install a proper diesel filter with water separator. Volvo sells one from Racor which I prefer. Even has that one in my sailing boat with a 28 Yanmar. (Quite an overkill, but proved its value on my trip!)
See this link:
http://www.marineparts.com/PARTSPAGES/RACOR/racor1.htm
Use only fuel additives for diesel engines. 'Gas line anti-freeze' (know it from Norway) is an emergency solution and not for permanent use.
When cleaning out the tank, check that the filling does not leak, and that the vent hose is properly installed."
 
"Sounds good. I have a Racor

"Sounds good. I have a Racor 500 fuel filter/water separator installed in-line ahead of the secondary filter, but the mechanic's "apprentice" bypassed it when he did my servicing, so the water went right past it and into the injection pump.

We still have to remove and bench test all of the injectors, in addition to cleaning out the tank."
 
""Question, though (Mo

""Question, though (Morten, maybe you can answer this one -). I obviously have to get the water out of my fuel tank. Removing the tank is not possible, as the builder pretty much hung a fuel tank in the air & built a boat around it. My (good) mechanic is suggesting a method of drilling a small hole in the top of the tank, and using a copper-tube probe to suck the water out of the bottom of the tank, then plug the hole with a fitting. Apparently he does this all the time on commercial boats, and it works well. I'm still assuming that even if we pump out all the water we can reach, there will still be traces left in the tank. "

There are companies that specialize in cleaning fuel and fuel systems. They will be able to get everything out and clean up the fuel. Look under "fuel polishing"."
 
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