1994 Seapro 190DC with 3.0l mercruiser with no power

[Rick Stephens]

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If you have EST ignition then to set the timing you need a jumper that turns off the advance so you can set timing. Here's a pic of anEST cap:


The right hand connector goes to the shift interrupt switch and is disconnected and replaced with the base timing jumper. That jumper, when correctly installed, takes all advance off your ignition. The engine doesn't run very well that way, but that is how you set initial timing. Here's the link specifically to the manual that covers setting timing with an EST ignition system. The specified base timing specification is 1? BTDC. The jumper looks like this picture:



Proper way to set timing with EST is warm your engine - I like having the timing light hooked up and the jumper installed but not hooked to power, so ignition is advanced. Once the engine is warm, hook up the jumper wire to power, which kills advance, set base timing to 1 BTDC. Tighten disty bolt. Recheck timing. Remove power from jumper and check advance curve. Should be around 12 to 14 BTDC at idle and ramp up to between 22 and 24 BTDC at 3000 RPM.

That will tell you your advance is working and your timing is correctly set.

Rick

 

[My7875]

10-4, that is what I have. Gotta go get a light when I get a few days/nights off work. Thank you for all the help

 

[My7875]

Ok I got a timing light. I can't download the link you sent until I get back to work. My phone isn't capable. I did build the jumper and put it in line. Mine however is just two wires that hang out of the dist. At any rate, I was about dead on 0. So I set it to 2 before TDC. The weird thing is there is no change with or without the jumper.

 

[My7875]

Also, I brought the rpm up to around 2k per the tack and rechecked and it was only about 3-4 after tdc

 

[My7875]

Nevermind last comment. Double checked everything and it looks like there is no advancement happening. Going to get a module and try

 

[My7875]

Module was bad so I got a new one but still only seems to be going to 4 btdc at 3000 rpm? Any idea where to look now?

 

[fishrdan]

I did build the jumper and put it in line. Mine however is just two wires that hang out of the dist.

The weird thing is there is no change with or without the jumper.

When the ignition goes into base timing mode it will drop timing, loose a little RPM and bog the engine. Are you doing anything else to put the ignition into base timing mode, besides connecting the jumper to the distributor? Once the jumper is connected, you need to short the shift interrupt wires together (disconnect the bullet connectors and join them together) then the engine should go into base timing mode.

Start and warm engine - connect jumper to distributor - jump shift interrupt wires - engine bogs - set timing - tighten clamp, double check timing - reconnect shift interrupt wires - remove jumper - check timing is now at 10-12* at idle and 24-28* at 2800 RPM.

I'm thinking your engine may be set at 2* advance out of base timing mode, so it may die when you put it into base timing mode, timing might be set to around 10* ATDC. You may have to advance the timing to get the engine to run in base timing mode (maybe not...).

If the jumper is left in place, timing may not advance, read that somewhere in a Merc manual / service bulletin.

 

[My7875]

I put the jumper on the module and bypassed the interrupter as instructed. Set timing as close to 1 btdc as instructed. After that I took the bypass off and took the jumper off the module but it still isn't advancing at idle or high rpm...... Going to have the new module checked this morning. The only thing out of the "check list" is a resistor that was on the coil to dist harness. We checked it a while back and it appeared to be bad and we took it out. Everything I read indicated it was only needed with the old points systems. Could it be causing an issue with the modules?

 

[My7875]

Ok, i wound up digging my old module out of my tool box because new ones just weren't working. I set the timing as instructed to 1 btdc and after removing the jumper etc, it was about 14 btdc. I took it to the lake and warmed the engine forma few minutes. When I gassed the throttle, it was spark knock city. I am beyond frustrated at this point.

 

[Pete104]

You can't just DISCONNECT your jumper!

Frustration is normal!

 

[My7875]

I don't understand what you mean. The instructions were clear. Set base time, turn off engine, take jumper off and reconnect interrupt, restart and check timing for advance.

 

[My7875]

Well I ended up doing a compression test and found two dead cylinders and what appears to to a patch job to get it sold with a new head gasket. Guess it's time to rebuild.........

 

[fishrdan]

Ugh... that sux... By patch job do you mean some sort of "JB Weld patch" or a hatchet repair job of throwing a head gasket on a warped head?

You may luck out (if you can call it that) and only have to rebuild the head and put it back together. Guess you'll find out when the head is removed.

Actually, before removing the head, remove the manifold and check the hidden side of the block, about 1" below the deck, and see if there is a JB Weld patch lurking behind the manifold. If a 3.0L block is going to crack, it's most likely going to be in that area, and since you found a hack repair job, who knows what you'll find. Reason for doing this first is so you can pressure test the block if needed, once the head is off you can't pressure test it (easily).

 

[My7875]

The old "put a gasket on and sell it trick". Got to have the head worked and block decked