starboard engine tach goes to 0 sync shuts down

[svaron]

During my trip today, we were cruising at 1250 RPM with the sync on. After 1 hour out, the starboard engine tech went to 0 and the starboard engine raced up to full throttle. I shut down the engine sync and pulled the throttle back. The tach remained at 0 for the duration of the trip.
I have 8 92's on my 1990 54 ED.

Any thoughts???


Sam

 

[MikeP]

You lost the slave engine tach signal to the synchronizer (cable broke, adapter broke, whatever). The synchro "saw" the slave engine rpm as below the lead so the synchro kept increasing the slave engine RPM trying to bring it up from "0" to match the lead engine.

Glendinning has an excellent trouble-shooting page which covers all this:http://www.glendinningprods.com/pdfs/sync_ts_guide.pdf

The synchro itself is about as close to a simple, bulletproof device as you can get.

 

[Nonchalant1]

Mike,

Check the tach drive cable on your engine. They are well known for quitting like this. They are a short stub flex cable that has been forged into square ends for the drive. The corners of the square ends round off or the cable breaks. The good thing is that Detroit Diesel uses these stub shafts on all kinds of engines and frequently has them in stock. Take your tach drive end off and check the cable. On mine, it pulls out easily from the cable side of the drive and pulls out hard from the engine drive side, but both are square corner ends on a round flex cable.

Doug Shuman

 

[svaron]

Thanks...so are both sides of the drives a square female (enigine and cable) with a square male connector?

 

[Nonchalant1]

Thanks...so are both sides of the drives a square female (enigine and cable) with a square male connector?

Both the drive and driven connectors are square female and both ends of the stub cable are square male ends.

 

[svaron]

Thank you for your input...

It seems that the problem , through Steve McPhersons several calls and assistance (GREAT SERVICE) was my Tach Drive Adapter. The connector piece was not stripped, however there was oil seeping through my current adatper which apparently indicates wear...

My question is, has anyone had any experience in getting the old one off the hydrico pump. It seens liike it should snap off and the old one snapped on. Steve also mentioned that there should be a 2.5 inch pin that should come out with the old one and that I should be carefull to not lose it as it is not replaceable.

Open to suggestions.


Thanks,