1999 Mercruiser 3.0L EST ignition not going into base timing.

I am working on a 1999 3.0L Mercruiser w/ EST ignition. It had a blown head gasket. I replaced the head gasket and put everything back together.

When I started the motor, the timing was very far advanced off the timing marks.

I am trying to set the timing. I went through the base timing procedure from the Mercruiser manual, but do not notice the engine slowing down at all. The timing reads the same whether I am hooked up in base timing or not. Here are the procedures I used:

Attached timing light to the #1 spark plug wire.
Started engine and ran it for a while to get up to temp.
Attached white wires on distributor with jumper lead.
Attached black wires on shift inturupter together.

I also tried to turn off the motor, remove the base timing setup, and then restart. This had no affect on anything.

At this point where I had the base timing connections attached I thought I would hear the motor slow down and run rough.

I am reading about 4-6 degrees btdc whether the base timing related wires are connected or not. The timing does advance if I rev the motor. Please help.

Re: 1999 Mercruiser 3.0L EST ignition not going into base timing.

Just a thought, Are you using a good quailty timing light?

My buddy had a cheap one and its was off by about 15 deg.

Re: 1999 Mercruiser 3.0L EST ignition not going into base timing.

natecollins1 said:

I am working on a 1999 3.0L Mercruiser w/ EST ignition. It had a blown head gasket. I replaced the head gasket and put everything back together.

When I started the motor, the timing was very far advanced off the timing marks.

I am trying to set the timing. I went through the base timing procedure from the Mercruiser manual, but do not notice the engine slowing down at all. The timing reads the same whether I am hooked up in base timing or not. Here are the procedures I used:

Attached timing light to the #1 spark plug wire.
Started engine and ran it for a while to get up to temp.
Attached white wires on distributor with jumper lead.
Attached black wires on shift inturupter together.

I also tried to turn off the motor, remove the base timing setup, and then restart. This had no affect on anything.

At this point where I had the base timing connections attached I thought I would hear the motor slow down and run rough.

I am reading about 4-6 degrees btdc whether the base timing related wires are connected or not. The timing does advance if I rev the motor. Please help.

Click to expand...

Are you connecting the two wires that are going to the interupter? The two wires coming out of the switch aren't the ones to connect....

Re: 1999 Mercruiser 3.0L EST ignition not going into base timing.

If your not connecting the jumpers from the distributor and the interuptor correctly you will not achieve the correct advance and or timming but if your are the most likely culprit is the module if it is do not buy after market use only AC delco. I would sugest starting over one step at a time through the procedure with a helper @ the throttle and you with the manual and removing the jumpers as needed through out the rpm graduations specified in the manual also make sur you have good continuity through you distributor jumper or your wasting your time and as stated by another Iboater use a good timming lite not a cheapy. Good luck!