Alternator, battery? Engine shuts down, Possible causes wanted

[Newbie]

Have you downloaded the Merc service manual for the 8.1? It tells you some good places to start checking along with wiring diagrams.

The OTC scanner I was referring to is the OTC 4000 enhanced. They are typically available used for about 100-150 on ebay

http://cgi.ebay.com/ebaymotors/otc-...QptZMotorsQ5fAutomotiveQ5fTools#ht_500wt_1282

You would also need the cable and chip from Merc. Part #'s 91-822560a13 and 91-880118a2. Those parts are about 150 and 180 ea.
The nice thing about the OTC is its the same scanner used by most Merc techs, Merc just re-badges it. When buying it used, it will normally come with a bunch of cables and chips for auto use up until the late 90's/early 2000's which is a bonus if you have any older vehicles.

 

[jjames002@socal.rr.com]

just replace the belt and keep the old one you should carry a spare anyway. good luck, jim

 

[Pseudomind]

just replace the belt and keep the old one you should carry a spare anyway. good luck, jim

I do not know if you are being serious or not as I have already mentioned the belt is good that the alternator was just changed.

Or are you attempting to make the "Stupid Post of the Day," thread?

Take this for what it is worth, unless you really like spam and if that is you correct email address as your user name, I would change it to something without my email address in it. :huh:

 

[Pseudomind]

It appears it was the fuel pump relay. It would "chatter" when it warmed up, unitl it finally just opened the circuit.

 

[Pseudomind]

Does anyone have a link to a graphically breakdown of this from Mercruiser's 8.1s manual? I know where the pump is located,I am looking for a breakdown graphic.

Seawater Pickup Pump Maintenance

I am guessing there is an impeller located inside this item? if not then just where exactly is it?:huh:

I have been searching and I have a .pdf of the Mercruiser engine manual; this is all it has in the manual no graphics or anything else.

*****************
From page 6A6 of Mercruiser 8.1 s manual

“Seawater Pickup Pump Maintenance
Whenever insufficient water flow is suspected, seawater pickup pump should be disassembled and inspected”
*****************

 

[Newbie]

No PDF but how about a pic or 2 of an 8.1's pump thats disassembled?

And yes, there is an impeller in there. Replacing the impeller? Easy. Removing and replacing the pumps from the engine? A bitch.

 

[Newbie]

Heres the breakdown

 

[Pseudomind]

No PDF but how about a pic or 2 of an 8.1's pump thats disassembled?

And yes, there is an impeller in there. Replacing the impeller? Easy. Removing and replacing the pumps from the engine? A bitch.

Heres the breakdown

Thanks I am copying and saving your post. Just what I was looking for, now why could not Mercruiser have at least put that graphic in there manual?

 

[Pseudomind]

I know these cost a bit, yet they are not real expensive. if it just might be worth while to purchase a spare unit, replace one engines pump with the spare unit. then change the impeller on the one removed and then replace the other engines pump..

Just an idea?:huh:

 

[Southpaw II]

The pump should never fail, but changing the impeller is a routine maintenance thing. Does your systems monitor display impeller pressure? This would be a precursor to impeller failure.

 

[Pseudomind]

Opinions, possible reason(s) . It appears (hopefully ) te fuel relay fixed my issue, but befor ethis was changed the alternator was changed. . Now when I start of at low RPM's and stay there my volt meter only reads 12 volts, once I am able to get to where I can increase the RPM's the guage will jump up to 14 and stay there, any ideas?

Thanks

 

[Feet From Satisfied]

Maybe you can help me.. I have a 01 38' and the starboard motor will start and run for about a min than shut down. I have swaped all 3 relays the ECM, both fuel pumps still the same thing. Once it shuts down it will not start again unless I leave it alone for a while and then it will fire for about a min, thats it... Any thoughts?

 

[midway]

Opinions, possible reason(s) . It appears (hopefully ) te fuel relay fixed my issue, but befor ethis was changed the alternator was changed. . Now when I start of at low RPM's and stay there my volt meter only reads 12 volts, once I am able to get to where I can increase the RPM's the guage will jump up to 14 and stay there, any ideas?

Thanks

Sound like the alternator has to have the rpm brought up before it will excite and start charging. I have seen alternators in the past that were built that way but not in a long time now. I really think it should start charging when you start the engine. Try bringing the rpm up at the dock and see what happens, if it picks up and charges then it has to have the rpm to start. Go check with your supplier to find out for sure how it should work.

 

[midway]

Maybe you can help me.. I have a 01 38' and the starboard motor will start and run for about a min than shut down. I have swaped all 3 relays the ECM, both fuel pumps still the same thing. Once it shuts down it will not start again unless I leave it alone for a while and then it will fire for about a min, thats it... Any thoughts?

Sounds like something shorted/heating up real quick that has to cool before the system will reset and allow the engine to run again. Now with that being said you would be better off to start your own thread for your problem. I think you will get more help that way instead of being in the middle of someone elses thread.

 

[Pseudomind]

I would suggest you see if yo can locate a Mercruiser mechanic who has a laptop or diagnostic software which will show whats is happening and a fault history.

I myself have attempted to contact Rinda about purchasing their software and never received a reply back.

Maybe someone here knows if you could be able to try your starboard ECM module on the port engine to see what it does?:huh:

 

[Pseudomind]

I have sent Rinda two emails with no replies received back as of yet, two weeks ago.

:thumbsup:

I received a reply back this past Saturday, 10/03/2009, post marked September 28, 2009 I wonder what happened?

Let's see I requested some information on 6/26/2009.:huh:
July 26
Aug 26
Sept 26