Offshoreonly.com - weird timing symptoms

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Quote:

Originally Posted by BUP (Post 4637728)

number 2 in the parts diagram. And the older ones had the ceramic filters inwhich come apart and clog alot of the fuel system up. You also should have a filter in the inlet carb side. That needs to be changed out every year as well.

Merc went to the paper element filter years later but the paper comes apart as well when not changed soon enough. Have no idea if you know this or not but passing it on for the taking.

And for the record the cam gear keyway wollow out --- the start of it is around the 200 hour mark. Does nt matter how pristene the engine is. It is a cheap soft gear. These engines were in a 1976 thru 1980 chevy chevette back in the day and not used in an auto since 1982.

MerCruiser 3.0LX GM 181 I / L4 1990-1995 Fuel Pump & Carburetor Parts

this is an industrial forklift engine.

Also as stated, 850 ohms on pickup coil, so within spec.

Fixed. Loose wire on ignition switch

loose wire on ignition switch

Went to lake last weekend. I could get on plane, but it takes a few seconds longer. At WOT, I only get 4000rpm (with a reduced pitch prop). Pulling a tube, it bogs until exactly 2400 RPM at which point you could feel the acceleration kick in hard and it goes right up to 4000rpm. This is exactly the rpm each time. Definitely not carb, but timing. I spoke with a marine mechanic and he said that the module is working. What is not working at this point is that it is stuck in base mode. I have followed the procedures over and over again and cannot leave base mode. I have unfortunately both of my available modules both stuck in base mode. Is there any way to reset them? The timing in base is absolutely correct. It just does not leave base mode. How can I tell? It stays at 1DBTDC. Only advances to about 12Degrees at 3000 rpm. I am clearly missing 1000 rpm at WOT and rpms struggle until about 2400 rpm under load at which point it goes but only to a max of 4000 rpm with a reduced pitch prop. With the stock prop, it only goes to about 3500 rpm max. With engine running, put shift interrupt switch back to normal, then removed jumper at distributor. Did this countless times as per manual.
Checked voltage at jumper and it is 12V+.
Ideas? No sense saying I am overpropped, carb etc. This is clearly a timing issue and solely to do with lack of advance.
It never leaves 1DBTDC at idle.
It should read 12DBTDC at idle when not in base mode.
Someone suggested to set it at WOT to whatever the advance is, but that is not good because it still doesn't have the proper advance curve.
Buying yet another module might be an option but I just feel that there must be a way to set the ones I have back to regular timing mode.

Quote:

Originally Posted by sashap (Post 4638801)

Only advances to about 12Degrees at 3000 rpm.
It never leaves 1DBTDC at idle.
It should read 12DBTDC at idle when not in base mode.
Someone suggested to set it at WOT to whatever the advance is, but that is not good because it still doesn't have the proper advance curve.
Buying yet another module might be an option but I just feel that there must be a way to set the ones I have back to regular timing mode.

So, move distributor for more base timing. :)

I'm just helping on the internet. It's free advice. You get what you pay for sometimes. It's not my engine. :)

BTW/: A 3.0L with two shots of nitrous isn't going to get me up on a ski. Just saying.

It's not the boat/engine that is the issue. It has a lot of power for what it is. The issue is that I know the ignition module is stuck in base timing mode. You can't just give it more. It has to be set to 1DBTDC at base mode. That is correct. It is the fact that the module is stuck in base timing mode.

i just read several places that the ignition modules that are aftermarket do not have the proper timing curve built in and do not do base mode correctly. Is this true? I have tried a cheap aftermarket as well as ACDelco d1964a. Both perform exactly the same. Neither either leaves base mode or simply don’t enter it. Wtf?

To all pros out there. Nobody mentioned that there are two types of est ignition modules for the 3.0. Same part number but different breed. The one ending in a stamped number 369 is automotive only with a timing curve that does not advance until 2400 rpm and then maxed out around 4000 rpm. The one stamped with a 399 is used for marine and some high performance uses with the correct curve.
Runs perfect now. Plus the automotive one has no base mode.

thats been talked about up here before and In my world its common knowledge about the modules. Sometmes a boater has to breakdown, buy actual marine parts paying more money -- YES more money or run into issues like this. I can not tell you how many times I have mentioned up here do not buy ignition parts and fuel injectors online and or many aftermarkets ones, And for the past 3 years mentioned SOME IACs aftermarket ones will not work correctly in MPI marine engines..

Whom told you buy the AC delco and online aftermarket modules ? I know I would nt have said that.