Engine Warms up and wont stay running

jralbert
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Re: Engine Warms up and wont stay running

Postby jralbert » Mon Aug 05, 2019 1:04 pm

Another non-gear-head response based on observations here over a long time: This seems heat related. Something heating up and failing. What's likely culprit? Is vapor lock an issue?
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

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Busia
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Re: Engine Warms up and wont stay running

Postby Busia » Mon Aug 05, 2019 2:48 pm

Yes, it is heat related. If it is vapor lock you won't have fuel in the float bowl and the accelerator pump won't squirt fuel. My guess is no spark, and the ECM is bad. It's the module mounted on the fire wall if it was a Dodge pick up. Yours will be nearby. Easy to change and you should have a spare anyway. Napa or any auto store has them. Search this site for more info on them, been lots of discussion on them.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW

jralbert
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Re: Engine Warms up and wont stay running

Postby jralbert » Mon Aug 05, 2019 3:49 pm

Just a little more than a yr ago, the same kind of query popped up with replies from the same varmints - you might find it useful (or at least, interesting)
viewtopic.php?f=27&t=1425&p=10196&hilit=stalling#p10196
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

Fastjeff
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Re: Engine Warms up and wont stay running

Postby Fastjeff » Tue Aug 06, 2019 6:12 am

You have to determine if the motor still has spark when this happens, to narrow down what's going on here.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

tedurocher
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Re: Engine Warms up and wont stay running

Postby tedurocher » Tue Aug 06, 2019 7:46 pm

okay, back at it tonight. I swapped parts to see if I could the problem to follow from one engine to the other.

coil, ignition module, breaker plate that contains the pick up coil and nothing really changed until . . . . I swapped the rotors. The stalling switched engines then. I put my spare rotor on from my last tune up and it fire right up and hasnt stalled since.

jralbert
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Re: Engine Warms up and wont stay running

Postby jralbert » Tue Aug 06, 2019 9:13 pm

Thnx for the followup (some folks don't do that) - are rotors subject to heat failure?
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

ddependo
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Re: Engine Warms up and wont stay running

Postby ddependo » Wed Aug 07, 2019 9:20 am

I believe Some electronic ignition systems require internal resistance coil and some do not . might check that.
Good luck.
Wayne
1973 32 express fly bridge
Chattanooga
"Southern Lady"

Fastjeff
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Re: Engine Warms up and wont stay running

Postby Fastjeff » Wed Aug 07, 2019 11:40 am

If those are the original distributors, there are two different rotors and caps that are NOT interchangeable.

Guess how I found that out!

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

Fastjeff
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Re: Engine Warms up and wont stay running

Postby Fastjeff » Fri Aug 09, 2019 7:37 am

Yes, Alice, you can teach an old dog new tricks!

Learned one just this morning on my Mercruiser 305 V-8, that was apt to cold stall after going into gear. (Very embarrassing at the ramp!) Here's the deal (and it translates to Mopar distributors and others): The electronic module in the deal bumps the timing 2 degrees when the motor reaches 1,000 rpm. Not realizing this, I had timed it at that rpm, which made the motor 2 degrees retarded. I retimed it just now with the idle speed on 700 rpm, then reduced the idle speed to get it back down to 700 rpm (it was at 1,000). The timing was STILL retarded, so I went through the exercise again, eventually getting my 8 degrees advance at 700 rpm. Motor sounds much now and I'm sure the cold stall issue will be gone.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

Fastjeff
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Re: Engine Warms up and wont stay running

Postby Fastjeff » Fri Aug 09, 2019 8:18 am

Addendum (really dumb!):

Lying there in the tub (where I get my best inspiration) I realized I had also made this dumb *ss mistake on my Marinette, which had "mysterious" hot stalls the entire time I owned it. Grrrr!

The bottom line here is: When You (or ?) is timing your engine(s), have a helper keep an eye on that tach! If the idle speed increases above, say 600-700 rpm (less is better), then turn down the idle speed at the carb and retime it. I had to go through this iteration several times before advance and idle speed was correct.

Hope this solves some problems for y'all out there (I'm a southern now).

Jeff (pronounced 'Jay-F' around here)
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington