3.7l mercruiser dies when warms up

[powersail]

Finally seem to have my mercruiser 3.7 running good... But... When I take it out on the water it runs great for about 20 minutes then dies like a kill switch was tripped. Is there anything on these engines that could be heat sensitive? Seems to die after it warms up. Engine is in a 1989 Regal and seems all original. And after waiting a while it starts right back up!!

 

[alldodge]

Re: 3.7l mercruiser dies when warms up

Finally seem to have my mercruiser 3.7 running good... But... When I take it out on the water it runs great for about 20 minutes then dies like a kill switch was tripped. Is there anything on these engines that could be heat sensitive? Seems to die after it warms up. Engine is in a 1989 Regal and seems all original. And after waiting a while it starts right back up!!

If it dies like turning the key switch off then it's probably electrical. Bring along a volt meter and see if you have 12 volts on the + side of the coil. If you have 12V then need to pull a plug wire and see if you are getting spark, Many initially suspect the coil breaks down and this can happen but it should be checked out first.

What's the serial number of the engine?

 

[powersail]

Re: 3.7l mercruiser dies when warms up

My original thought was the coil too, but I was with another boat that has the same engine, so I tried his coil and that didn't work either....have to get the serial number tomorrow...

 

[alldodge]

Re: 3.7l mercruiser dies when warms up

Your probably loosing spark and that can be from the distributor components, electrical connections or fuel pump if it is EFI

 

[powersail]

Re: 3.7l mercruiser dies when warms up

It definitely sounds/feels electrical...no EFI...what would I check from the distributor?

 

[alldodge]

Re: 3.7l mercruiser dies when warms up

The distributor has points, and the condenser could get hot and breakdown. If you don't have points and have digital ignition then it could be your control module. Need to find out if you have 12V at the + side of the coil after it dies. If you do and you have a RPM gauge, disconnect the wire and see if it fires up.

 

[powersail]

Re: 3.7l mercruiser dies when warms up

I'll give it a try...thanks!!

 

[powersail]

Re: 3.7l mercruiser dies when warms up

Changed the condenser but didn't get a chance to try it on the water yet. Ran great on muffs, so we'll see....