Dies when throttling up from idle after warm up/ 89 merc 3.7 2bbl

[karayj]

Get a dwell meter. If dwell is off you've got no chance at getting this thing to run right. Verify dwell then check timing

I know the gap is 22 and the dwell 32?

 

[karayj]

Should I be this one which is Prestone or AC Delco ? they have different gaps and dwells
I am thinking I should BE AC delco / How can I tell

 

[karayj]

or this one My money is on this one

 

[Eric 3.7LX Alpha 1]

Should I be this one which is Prestone or AC Delco ? they have different gaps and dwells
I am thinking I should BE AC delco / How can I tell View attachment 348584

Take a look at the two pages I have attached.. one of each style distributor. Notice the cap shape between terminal posts. The Delco is more rounded. I have the Delco in mine.

 

[Eric 3.7LX Alpha 1]

The point gap gets you close. You need to get the dwell within spec then check the timing, which will move when you move the dwell, so check timing after getting the dwell set.

 

[Eric 3.7LX Alpha 1]

Also, the side of the cap on the Delco has a shelf or tapers in at the base of the posts where the wires connect, the Prestolite side is straight up to the top.

 

[karayj]

So I gap my pints at 22 and the dwell read 55 !!!!!! WTF and then I closed the gap and it did not help. Another thing I noticed was the lobes are not sharp the are rounded it that normal on a merc?

 

[karayj]

So guess what I DID NOT connect the dwell meter properly. RED to coil neg and neg on the dwell meter to ground OPPS
I will report back tomorrow

 

[karayj]

Can someone tell me the proper dist for my boat J1172 or J354

 

[karayj]

Can someone tell me the proper distributor for my boat J1172 or J354 I see these number for sale but they don't seem to matter they are SEA Models types I think. 1989 merc 3.7 470

 

[Eric 3.7LX Alpha 1]

J1172 and J354 are not part numbers, they are US Coast Guard standards that many distributors meet. They don't tell you what model you have.

I also have an'89 3.7LX and I have the Delco distributor. I would guess you would also have the same. Snap a photo of what your dizzy
looks like...

 

[karayj]

I did the Dwell and LOL I was of by 3 33 instead of 30. So today all went well trying to burn off gas before winterizing and after 25 min of cruising14 mph I decided to head in an she stalled. I restated and 15 seconds later died. Restarted and died after 10 seconds and then 5 seconds. I waited 5 min restated and she ran for 1 min and then died. The SAME EXCACT Thing happened last year when trying to burn off fuel. WFT!!!! so I get to the dock and like last year restarted and she ran for 15 min LIKE LAST YEAR!!! During the regular season I don't cruise around I drop in drive 15 min anchor and sit for 3 hours. So what is causing this ? Overheat ? I changes the coil to a 3 ohms coil that can handle heat better. Do I need to vent the engine compartment better? I have the side vents the 4 inch ducts and the blower.

 

[Eric 3.7LX Alpha 1]

Did you check timing after changing dwell? When you move the points, the timing also changes.

Do you have a temp gauge to confirm your engine temp? You should, these 470/3.7 motors don't like to overheat.

What's your voltage while running, on the (+) side of the coil. It should not be 12 volts with points. There should be two wires on the (+) side of the coil. One off the starter solenoid that gives the coil full 12 volts when cranking the engine only to help start the engine, and a second wire which lowers voltage when running. If you have full 12 volts to a points coil that are suppose to be fed thru a resistance wire they can get hot after a while and cause problems with spark.

 

[Benny67]

I did the Dwell and LOL I was of by 3 33 instead of 30. So today all went well trying to burn off gas before winterizing and after 25 min of cruising14 mph I decided to head in an she stalled. I restated and 15 seconds later died. Restarted and died after 10 seconds and then 5 seconds. I waited 5 min restated and she ran for 1 min and then died. The SAME EXCACT Thing happened last year when trying to burn off fuel. WFT!!!! so I get to the dock and like last year restarted and she ran for 15 min LIKE LAST YEAR!!! During the regular season I don't cruise around I drop in drive 15 min anchor and sit for 3 hours. So what is causing this ? Overheat ? I changes the coil to a 3 ohms coil that can handle heat better. Do I need to vent the engine compartment better? I have the side vents the 4 inch ducts and the blower.

You've got a bad connection or crimp somewhere I'm betting.

Spend some time checking for corroded or loose connections.

 

[zellerj]

Why don't you just put an electronic ignition on your engine and be done with points and condensers. Electronic ignitions are easy peasy to install. Most people with old engines do this because the lobes on the distributor round over time and it is difficult to set the dwell correctly.

 

[Benny67]

Why don't you just put an electronic ignition on your engine and be done with points and condensers. Electronic ignitions are easy peasy to install. Most people with old engines do this because the lobes on the distributor round over time and it is difficult to set the dwell correctly.

I agree. I switched both my 3.7s about 6 years ago and glad I did. You definitely get easier starting and I'm not screwing around with points anymore. I do keep an extra module on board because I've heard they aren't reliable but it's been 6 seasons and I haven't had any issues

 

[karayj]

Did you check timing after changing dwell? When you move the points, the timing also changes.

Do you have a temp gauge to confirm your engine temp? You should, these 470/3.7 motors don't like to overheat.

What's your voltage while running, on the (+) side of the coil. It should not be 12 volts with points. There should be two wires on the (+) side of the coil. One off the starter solenoid that gives the coil full 12 volts when cranking the engine only to help start the engine, and a second wire which lowers voltage when running. If you have full 12 volts to a points coil that are suppose to be fed thru a resistance wire they can get hot after a while and cause problems with spark.

I replaced the coil with a 3 ohms for this reason . Overheat.

 

[karayj]

I am going to get rid of points I am tired of them . There is a kit for 70.00 I have seen on ebay

 

[karayj]

I do think it’s an overheat problem because it only happens after a 30 -40 min of driving 15 mph.

I have tested the temp control switch and ohms wise it was working as it should.

The gauge seems a bit off and never seems to get hot could be a bad gauge. I will also say the auto shut off for overheat has been removed so it can’t be that. I should have vented the engine a bit better by pulling back the engine cover. Normally I run it for 15 min to the island then shut it off and sit for 4 hours and then head back in.

I also should have ran the blower when I was idling that has helped I think. The other question is what is he solution to fix this ?

 

[Benny67]

I do think it’s an overheat problem because it only happens after a 30 -40 min of driving 15 mph.

I have tested the temp control switch and ohms wise it was working as it should.

The gauge seems a bit off and never seems to get hot could be a bad gauge. I will also say the auto shut off for overheat has been removed so it can’t be that. I should have vented the engine a bit better by pulling back the engine cover. Normally I run it for 15 min to the island then shut it off and sit for 4 hours and then head back in.

I also should have ran the blower when I was idling that has helped I think. The other question is what is he solution to fix this ?

If it was me, I'd swap out the points and coil for a pertronix setup.

It's a quick and inexpensive upgrade.

Like I wrote earlier, I've upgraded both my motors and have been pleased with the results.

Buy the matched set and see if it solves the issue. At least if it doesn't you still have a better system than the points.

Also,

I noticed that you seem to believe that the coil gets too hot after running it for a length of time. Maybe you might want to bench test the coil resistance at room temperature and then heat it up with a hairdryer and see if you see a difference in its resistance when its heated.

I've seen coils fail over the years and they usually just fail. However, anythings possible.

You might want to do that before swapping out the points.