Westerbeke 52: New fuel injector pump = overheating

[nknowland]

Our W52 with 5500hrs started overheating above 2150 rpms (190 deg) after the fuel injector pump was recently replaced. I read the above thread on the Yanmar overheating and picked up a couple of suggestions (majority had already been done).

But since this was not a problem before the fuel injector pump was replaced, any ideas on what the connection would be?

Thanks

[Nord Sal]

I have my fuel injection pump out of my W52right now and am reading your thread for ideas.

Could this be related to the pump timing? i.e., if the ignition is slightly advanced or retarded could that cause overheating? That's the only thing I could think of assuming the pump was serviced correctly.

I'd be interested in hearing iof you figured this out and what your final diagnosis/solution was.

[a64pilot]

Advanced timing can / will cause overheating, usually hard starting too as in starter spins it slower than it used to, reason is the ignition is occurring too soon and kicking the piston in the face prior to TDC, old hand start cars for example you retarded the timing to start, or you got hurt when it kicked back
Retarded timing can / will cause low power.

However there should be enough reserve cooling capacity for your system to absorb the extra heat so even if it works out to be too advanced timing, still should look at your cooling system

[Diesel Bill]

I was called in to diagnose and repair a Detroit Diesel that was overheating. It was the middle of salmon season and this was a party head boat. The owner was loosing money every day the boat was tied to the dock. Long story short, I went through all the obvious,
sea suction strainer, water pump impeller, heat exchanger. Water flow over board was good. Turned out the guy who overhauled the motor missed the timing gear marks and got the cam 4 teeth advanced. That worked out to 26 deg advance with the exhaust valves closing way to soon before the inlet ports were able to sweep the cylinders with fresh air. I found this by running a dial indicator on the unit injector of # 1
cylinder and measuring plunger travel before TDC. Took about a week of work to pull transmission, bell housing, flywheel and gear housing to verify and reset gear timing.

[Nord Sal]

The timing marks on my W52 are not visible. Westerbeke's motor mount bracket obscures the engine manufacture's timing marks on both the timing case and the injection pump. I punched my own marks on the motor mount bracket and injection pump flange prior to the pump's removal so I can reinstall it with the correct timing.

If no new marks were made, the pump would have to be timed (per the Westerbeke Tech manual) by freeing a valve to rest on the piston and using dial indicator on the valve and a second dial indicator on the injection pump - a much more involved procedure.

Is it possible the pump was reinstalled without new timing marks or without using the dial indicator technique Westerbeke specifies? If so, perhaps the pump was installed close enough so that it only overheats at higher RPMs? A marginal cooling system like what might be seen on a older engine would likely be really taxed in this scenario as well.

[nknowland]

Originally Posted by Nord Sal

I have my fuel injection pump out of my W52right now and am reading your thread for ideas.

Could this be related to the pump timing? i.e., if the ignition is slightly advanced or retarded could that cause overheating? That's the only thing I could think of assuming the pump was serviced correctly.

I'd be interested in hearing iof you figured this out and what your final diagnosis/solution was.

Hello,
Sorry for the delay in replying. We are in the Bahamas with sketchy internet.

The timing on our pump was set by the mechanic who rebuilt the pump so when reinstalling we just had to align the slot correctly.

We have been bothered by overheating for awhile. We did a baseline temp of 22 spots on the engine and took that spreadsheet to a mechanic. He suggested the heat exchanger might be a problem. We had recently had the HE serviced, but the mechanic thought it may just be old, fatigued, and not doing it's job well.

We bought another HE and were quite surprised to see that the new one was 3 inches longer than the one installed. Our guess is previous owner made the replacement with an undersized unit.

That did the trick for us. We also now use a digital thermometer to take engine temp readings as our temp gauge on the panel routinely runs 5 degrees hotter than engine actually is (even after replacing the gauge, sender, and wiring).

This forum was a great help when we had to remove the pump ourselves. I hope you find some answers that help you too.

[kevins]

I have to rebuild my fuel injector pump. Did you have to remove the timing cover to remove the pump? If you did not remove the cover, how did you hold the gear in place which is on the pump's shaft in order to not alter the gear teeth alignment thereby messing up the timing? Also how did you not drop the shaft key into the timing cover containment when removing the pump?

Thanks kevin

[Nord Sal]

You do not have to remove the timing cover to pull the injection pump.


After you remove the raw-water pump drive tang from the end of the injection pump shaft, you can hold the timing gear in place with one hand while you slide the pump aft with the other to pull the pump.


My woodruff key was oriented "up" and came out with the pump without a hitch. If you find yours in another position, turn the engine as required so that it sits upward before pulling your pump.



I used a zip ties to hold the timing gear and friction washer in place in the timing case while I had the pump out. I think the gear would've stayed in place without doing this, but it gave me peace of mind while the pump was away for servicing.


My timing marks were obscured by a motor mount and I suspect yours are too. Before I removed my pump, I made my own timing marks (adjacent punch marks on pump flange and timing cover) to re-align the pump when I re-installed it. I've now acquired an endoscope (bore scope) and can see the original marks with this really handy device so that might be another option for you.



I installed the injection pump gasket to the pump with gasket adhesive on the injection pump and let it fully cure before re-installing the pump. I did not use gasket sealer of any kind on the timing case side, just a little engine oil. This allowed the the pump to easily rotate for timing once it was mounted. If you use Permatex or gasket adhesive on both sides I think it would make this a sticky job trying to finely move the pump to align the marks and possibly damage the gasket. YMMV



My boat is fairly small. I did this job mostly laying on my belly on a 2 x 12 I cut to fit over my engine compartment when the hatch is open. I removed the intake manifold and air box, fuel lift pump, secondary fuel filter mount and the dipstick to get clear access to the pump.



I used Diesel Injection Specialists in Portland OR on the recommendation of my local machinist. They were outstanding in communication, service and got the job done quickly and for a fair price. I highly recommend them if shipping from your locale is feasible.



BTW I have a second pump that the shop checked for me and okayed if you're interested. I got it from the classifieds here on the CF when I purchased a bunch of W52 parts from a member who had re-powered. Let me know if you're interested.


It's now been about three years since this job became another one for the books. The most difficult thing I can remember was getting some of the clamps and brackets for the Morse cables re-installed because of access and visibility. Overall it went smoothly. Good luck!

[kevins]

Thanks for the information....it helped and I was able to remove it.... currently at the repair shop mn