Novice boat owner needs help: 1989 Mercruiser 3.0 won’t start

[Reacher558]

I attached the new condenser and new points and tried to start. No change in the engine when it tried to start. It is still cranking but won’t start.
I placed the voltmeter on one of the plug wires coming out of the distributor cap and got a reading of .04V. Not sure if that helps? There is still 12V going from the coil into the distributor but no spark coming out of the distributor best I can tell.

 

[alldodge]

The coil puts out over 5,000 volts, so placing a meter probe on the plug wire will blow the meter if it does spark

There should be 12V on the + side of the coil

When the motor is cranking, does the distributor rotor rotate?

If it does rotate, do the points open and close 4 times with each rotation? So as the rotor tuns the points will open when the distributor lobe contacts the lobe, and close completely as it comes off the lobe

 

[Reacher558]

Very helpful video, thanks. The rotor is definitely rotating since it is in a different location than it started last time I tried to start the motor.
I have the distributor cap off now and am looking closer. Is it ok to crank the motor with the cap off to see if the points open and close 4 times? If not, what is the best way to tell if they are opening and closing?

 

[alldodge]

Yes, ok to crank with cap off

 

[Reacher558]

Thanks! I cranked it with the cap off. The shaft is turning and it looks like the points are touching like the video (4 times a turn). I can see a spark coming off of the point.
I am insure if the gap is just right though. I am going to try to adjust it again tomorrow.
In your instructions, you mentioned rotating the distributor. I might not have followed that correctly. Did you mean to take the bolts off of the bracket that holds the whole distributor in place?

 

[tpenfield]

Wow - point and condenser ignition system . . . that takes me back a few years (like 30-40 years)

If you are getting a spark at the points, then you probably should be getting a spark at the spark plug. That would be something to try, then check the timing. the engine should start if the timing is close . . . does not have to be perfect. you can set the timing once it is running.

You only need 3 things fuel - compression - spark So it is a process of elimination to find out which one(s) you don't have.

 

[alldodge]

Agree, if your getting a spark at the points then you should get a spark at the plugs

Did you mean to take the bolts off of the bracket that holds the whole distributor in place?

There is one bolt which holds the distributor down. It would be loosened just slightly so the distributor can be rotated left/right if needed. This is how timing is adjusted.

 

[Reacher558]

Thanks for the responses, Dodge and Ted! I am going to dig back in in a few hours and keep working on the distributor. I will post an update after I reinstall the points and give it another try

 

[Reacher558]

Update:
I reinstalled the points to .022 as instructed. I also replaced the spark plugs just in case. When replacing the spark plugs, I noticed the wires did not appear to be in the correct order. I looked up the firing order and found 1342 as the firing order for this engine. (please correct me if I am wrong).
after reinstalling the points, I tried to crank the engine again and it would not start. I pulled one of the spark plugs out and held the wire with rubber coated pliers as the engine cranked and did not see a spark but did feel a slight shock in my finger. This is probably not the right thing to do but I think I found out that there is current flowing through the wire. I’m not sure how easy the spark would’ve been to see since it was daylight at the time.
when I replaced the spark plug and before starting the engine again, I Sprayed starter fluid in the carburetor again. When I Cranked the engine again, it caught a couple of times but did not turn over. When I tried to crank it again, I did not hear it catching again. Do you guys think there could be an issue with fuel getting into the engine? The bottoms of the spark plugs that I changed were not wet as I’ve heard they should be if the engine is not getting spark?
would it be worth changing out the rotor?
not sure what the next troubleshooting step is from here. Thanks again for all of your help.

 

[Bondo]

Do you guys think there could be an issue with fuel getting into the engine?

Ayuh,..... Sounds like it to me,..... Ditch the startin' fluid, 'n dump 'bout 3 or 5 tablespoons of gas down the carb, 'n try it,.....
If it tries to start, figure out where the problem is in the fuel system,......

 

[alldodge]

Yes, firing order is 1-3-4-2. Number 1 is the front plug and distributor turns clockwise
When rotor is pointing to number 1 the timing mark on the pulley should be at the marks on timing chain cover

To fin out if your on number 1 compression stroke, remove plug number 1 and stick your thumb against the hole then crank the motor by bumping the starter. When your thumb is pushed out, look and see where the rotor is pointing. If your unable to crank the motor and hold your thumb on the hole, use a cork or something similar

Now adjust plug wires to 1-3-4-2 in clockwise direction on the distributor cap

The spark if its working correctly would make you jump and release it real quick. The spark shock is pretty intense

Disconnect the throttle linkage on the carb and then pump the carb. You should see fuel squirt in throat of carb. If you don't see any fuel squirt in, then need to find out why

 

[Reacher558]

Thanks, Bondo!
i just tried and it was a no go. Engine still sounds the same when cranking but won’t start.

 

[Reacher558]

Thanks, Dodge! It was a pretty intense shock that made me drop the wire. I will start working on the timing and find out if fuel is shooting in the carb. When I had the plug out I did see/feel air shoot out of the hole at one point.
If the timing is off will that prevent it from starting?

 

[poconojoe]

Ah! Good ole' troubleshooting! All great advice. I'm gonna follow along just to see how you make out.

If you look up inside the distributor cap, are the 4 contacts clean and shiny? How about the rotor? I've seen some that were badly covered with crusty green and white corrosion.

Maybe instead of holding an ignition wire near the block for testing, pull a spark plug and plug it back into it's wire. Ground the side of the spark plug to the block while cranking. Use an insulated tool to hold it. You should see a nice blue spark in the gap of the spark plug and even hear the snapping sound it makes.

I wouldn't want you to spend needless money, but it would probably be a good idea to replace the cap, rotor and wires.

But as suggested, let's first see if the problem is fuel related.

 

[Reacher558]

Dodge, what did you mean by “pump the carb”?

 

[alldodge]

If the timing is off will that prevent it from starting?

If its far enough out, yes, but in most cases there would be backfiring from fuel and plugs firing at the wrong time

 

[Reacher558]

And Poconojoe, thanks for the advice! I will give that a try to see if there is any spark coming from the plug.
i was told the distributor cap was recently replaced and it looks really clean. The rotor also looks really clean as well.

 

[Reacher558]

alldodge Gotcha, thanks

 

[Reacher558]

Update:
I was able to see a spark coming from the plug with it pulled out and plugged into the wire!

I also did not see any fuel squirting into the carb when pumping the throttle. I attached a pic of the wires coming from the distributor (I think they are in the correct order).

 

[Reacher558]

Also, this is a link to video showing the carb while the throttle is pumped if that helps?