CAT 3208 turns over will not start...

Osprey69 · Feb 25, 2022

bowball said:
I’m a bit confused. You said it ran fine at dock and then a week later no start. But you changed the solenoid in that time period? Wasn’t that the last action before it didn’t start?

I think the thread is informative and interesting can you give us your lessons learned?

Solenoids changed last fall. The diode in the power line to the solenoid failed whilst the boat sat on the dock and when I went to re-start the engine it did not.

A seemingly simple repair (installing new power line/diode) might still deserve a glance at the directions. Caused all kinds of bunny holes to be explored. Learned a lot in the process. though. So there is that.

RickyD · Feb 25, 2022

Osprey69 said:
Portage. We swapped out running port fuel shut-off solenoid and no joy. They were both replaced (at my instruction as one was suspect at engine survey) last fall. We have been dancing all over those connections as well.

Well check fuel flow just to make sure.

Thanks.

If you have a Fireboy fire suppression system it may have failed or half of it. I had that happen. Chased all kinds of things first. If you have one you can disable it from its control and monitoring panel. Mine is on the fly bridge. Worth a try. My old one had a circuit board controlling the port engine and another for the starboard engine. Port engine would not start until we disabled the Fireboy. Then we upgraded to a new style with one circuit board. All is now happy.

twistedtree · Feb 25, 2022

OK so the diode failed and was diagnosed by a mechanic. You replaced the diode, but installed it backwards, and that has been the problem ever since?

slowgoesit · Feb 26, 2022

twistedtree said:
OK so the diode failed and was diagnosed by a mechanic. You replaced the diode, but installed it backwards, and that has been the problem ever since?

I believe he was saying that it was unidirectional, to some extent, so since it was installed backwards, it worked FOR AWHILE, then failed recently. Since it was working for awhile, he did not connect that replacement last Fall, with the recent problem.

twistedtree · Feb 27, 2022

slowgoesit said:
I believe he was saying that it was unidirectional, to some extent, so since it was installed backwards, it worked FOR AWHILE, then failed recently. Since it was working for awhile, he did not connect that replacement last Fall, with the recent problem.

Ok, I read it differently, but frankly the whole story has been hard to follow. Of course a diode is inherently unidirectional. That’s it whole purpose in life. If installed backwards, it would explain all the symptoms. My recap was an attempt to clarify what happened, since it has been so scattered and unclear.

Osprey69 · Feb 27, 2022

twistedtree said:
Ok, I read it differently, but frankly the whole story has been hard to follow. Of course a diode is inherently unidirectional. That’s it whole purpose in life. If installed backwards, it would explain all the symptoms. My recap was an attempt to clarify what happened, since it has been so scattered and unclear.

[*]Engine ran at dock
[*]Engine did not start at dock a week later.
[*]Failed diode diagnosed on fuel shut-off solenoid power line.
[*]Ordered replacement part via CAT
[*]Replacement installed, (albeit incorrectly...see below).
[*]Engine did not start.
[*]Bunny hole searching ensued assuming a correct power line with a diode.
[*]Finally swapped out shut-off solenoid power lines as a last resort (yup should have done that earlier).
[*]Engine started and runs fine.

The following is new info.

Installed new power line correctly yesterday. No joy. Tested replacement power-line. There is no diode in it (as led to believe) and no matter how installed was not going to work. So I ordered diodes (replacing port and starboard and will have the original as a spare) that can be dropped in easily.

SteveK · Feb 27, 2022

Osprey69 said:
[*]Engine ran at dock
[*]Engine did not start at dock a week later.
[*]Failed diode diagnosed on fuel shut-off solenoid power line.
[*]Ordered replacement part via CAT
[*]Replacement installed, (albeit incorrectly...see below).
[*]Engine did not start.
[*]Bunny hole searching ensued assuming a correct power line with a diode.
[*]Finally swapped out shut-off solenoid power lines as a last resort (yup should have done that earlier).
[*]Engine started and runs fine.

The following is new info.

Installed new power line correctly yesterday. No joy. Tested replacement power-line. There is no diode in it (as led to believe) and no matter how installed was not going to work. So I ordered diodes (replacing port and starboard and will have the original as a spare) that can be dropped in easily.

Engine started and runs fine after a swap of shut-off solenoid.
Now a new power line installed and it does not work again. :ermm:

Yes it is hard to follow along.

Deano · Feb 28, 2022

Diodes by their nature are directional.

ronobrien · Feb 28, 2022

tiltrider1 said:
If a mechanic is having an issue sourcing the problem, it’s not likely we can help.

Just in case some one missed one of the basics let’s review a few things. Is there fuel in the tank? Are all the valves in the open position? Have you primed the engine to confirm there is fuel to the High Pressure Pump? Have we confirmed that the fuel shut off solenoid is functioning?

I'm glad you asked the question about fuel in the tank. I was thinking of Carl (Billie Bob Thornton) in Slingblade. "Hmmm, ain't got no gas"

contingensea · Feb 28, 2022

Ahh, 3208’s mysteries abound!

Probably are aware already but, be careful the lift muffler does not fill up with water during all the cranking. Hate to see you have a REAL problem!

Haven’t had the problem yet that you are experiencing with my relatively new to me 3208’s but, I’m sure I will.

Please post the resolution when known.

You could call Diesel Don, Florence AL. Not sure if he consults over the phone though.
http://www.jaysboats.com/ddon.asp

Greggnvt · Feb 28, 2022

Make sure the transmission is in neutral. Move it back and forth (forward/reverse) - wiggle it around in neutral while turning the key.

On my boat, you have to turn the keys on the 12 DC panel as well as turn the 12v breakers on -

SteveK · Feb 28, 2022

Deano said:
Diodes by their nature are directional.

otherwise they would be called BIODES

Greggnvt · Feb 28, 2022

Someone already mentioned the fuel primer - there should be a bleed valve-lever that you can open, while pumping, to ensure you've got fuel (remember to close the bleeder valve!)

Picture of my DC panel Ign. Switch's/breakers.

tiltrider1 · Feb 28, 2022

This is why I always promote a methodical A to B approach for diagnostics. It doesn't matter if the OP's mechanic had started at the injector or the fuel tank. In very short order the mechanic would have discovered fuel on one side of the solenoid and not on the other. At that point it doesn't matter if the solenoid had just been replaced, its the problem, at that point one can then investigate if its electrical, mechanical or improper installation. Jumping from one possibility to the next just sets you up to chase your tail.

twistedtree · Feb 28, 2022

For those jumping in now, the problem has been solved. The original failure was in a blocking diode for the fuel shutoff. The OP incorrectly installed the replacement, and tail chasing ensued and continues. It’s amazing how many times one can hit themselves in the head with their own hammer.

SteveK · Mar 1, 2022

At that point it doesn't matter if the solenoid had just been replaced, its the problem,

But in no way is something we fixed yesterday the problem today. :nonono:

Remember to fix it until it is broken.

ofer · Mar 1, 2022

twistedtree said:
Of course a diode is inherently unidirectional. That’s it whole purpose in life. r.

bowball · Mar 1, 2022

twistedtree said:
For those jumping in now, the problem has been solved. The original failure was in a blocking diode for the fuel shutoff. The OP incorrectly installed the replacement, and tail chasing ensued and continues. It’s amazing how many times one can hit themselves in the head with their own hammer.

I could see why the diode was ignored as a problem as after first installed correctly the engine ran properly. So despite being installed in the wrong direction it still allowed functioning? That’s the part that confuses me if I understand it correctly.

tiltrider1 · Mar 1, 2022

bowball said:
I could see why the diode was ignored as a problem as after first installed correctly the engine ran properly. So despite being installed in the wrong direction it still allowed functioning? That’s the part that confuses me if I understand it correctly.

You are assuming that you got just the facts and all of the facts. I highly doubt you got both.

twistedtree · Mar 1, 2022

bowball said:
I could see why the diode was ignored as a problem as after first installed correctly the engine ran properly. So despite being installed in the wrong direction it still allowed functioning? That’s the part that confuses me if I understand it correctly.

That’s not my understanding of what happened, but who can be sure :-(

I understood that after a mechanic diagnosed the bad diode, the OP replaced it and that engine still wouldn’t start. So assuming it was a different problem, they went down a bunch of other rabbit holes not realizing that the diode was just installed backwards. But I could have that completely wrong…..

SteveK · Mar 1, 2022

twistedtree said:
That’s not my understanding of what happened, but who can be sure :-(

I understood that after a mechanic diagnosed the bad diode, the OP replaced it and that engine still wouldn’t start. So assuming it was a different problem, they went down a bunch of other rabbit holes not realizing that the diode was just installed backwards. But I could have that completely wrong…..

I think you may have answered it. If the OP installed it backwards why would it start?

Maui · Mar 1, 2022

I’ve had my two 1982 Cats 3208T’s for six years. Five years ago I looked at a bunch of old relays and diodes that were mounted near the ignition solenoid that were clicking randomly when the key switch was on. They were not causing problems. It just seemed like a place for something to go wrong. It looked too complicated for me. A Cat 3208 is a very simple engine. If power is applied to the solenoid, fuel is in the injectors, air is available, it will start in 1/8 of a revolution. So I took out all the old clicking relays and diodes and rewired the fuel solenoid directly to the key switch. I also rewired the the rest of my boat while I was at it. Ran great. This year I took the boat from Long Island to The Exumas. 1450 miles in 19 days cruising at 17 knots. 1850 gallons of diesel. Ran like kittys. Not one problem. Heading back to NY in May.

Osprey69 · Mar 4, 2022

Soo-Valley said:
Engine started and runs fine after a swap of shut-off solenoid.
Now a new power line installed and it does not work again.
Yes it is hard to follow along.

Yup. Forgive the imperfect narration. Business is booming (supply chain headhunter) and so are my distractions.

Yes I now know a diode is unidirectional.

New power line from Cat did not include diode at all so I made two mistakes there. Bad part and bad install.

Yes it then became a rabbit hole fiesta.

Made up my own power lines with diodes and all is good.

Moving on...

CAT 3208 turns over will not start...

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