Won't run when hot

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leapfrog85
United States of America
Posts: 3
Joined: Thu Nov 05, 2020 10:17 pm

Won't run when hot

Post by leapfrog85 »

Hey all,

So, the other day i was driving my '75 710M when I pulled up to a stop light and it backfired really loudly and then stalled. I then drained the battery trying to restart it. After getting a jumper pack I tried to restart it again with no luck. I pulled the center lead on the distributor to make sure I was getting a spark at least that far, and I was. I also shot some ether in the intake to see if it would fire that way with no success. I ended up having it towed but the next day it started and drove just fine. Why would it stall and not restart, even with ether, only to run fine when it cooled down? Any ideas will be greatly appreciated.

Aaron
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rmel
United States of America
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Joined: Sun Sep 25, 2011 12:19 pm
Location: Woodside, CA
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Re: Won't run when hot

Post by rmel »

Possibly Vapor lock ? What was the temperature and altitude where this happened.
And how full/empty was your fuel tank.

If this happens again, try removing the top cover off the dog house, wait a couple of
hours and attempt to restart.

A friend had this problem on hot days at altitude. He decided to flip over to a
electric fuel pump, rather than rebuilding the mechanical pump.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
leapfrog85
United States of America
Posts: 3
Joined: Thu Nov 05, 2020 10:17 pm

Re: Won't run when hot

Post by leapfrog85 »

Vapor lock was my first thought too. Would that account for the loud backfire, or for it to stall? I'm at less than 1,000 feet and the temp was in the mid 50s, which would kind of make me lean away from vapor lock. Plus, I would think it would start with the ether.

Thanks
Aaron
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rmel
United States of America
Posts: 1394
Joined: Sun Sep 25, 2011 12:19 pm
Location: Woodside, CA
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Re: Won't run when hot

Post by rmel »

Those conditions makes vapor lock less likely.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712MK

Driver: Ron // KO0Q
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David Dunn
United States of America
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Joined: Wed Apr 14, 2004 7:08 pm
Location: Arcadia, CA

Re: Won't run when hot

Post by David Dunn »

Look at the coil. That's the same symptom as a coil going bad. A coil breaking down will get extremely hot and spark gets weak. It will continue to run, but if stopped , it won't restart for a 1/2 hour or more until it cools down. This can also be caused by overvoltage from a failing ballast resistor or a bad voltage regulator supplying over 30+ volts to the electrical system.
If it happens again or take your Pinz for a 1/2 hour drive or so, then check the coil to see if it's hot to the touch
.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .




ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)
leapfrog85
United States of America
Posts: 3
Joined: Thu Nov 05, 2020 10:17 pm

Re: Won't run when hot

Post by leapfrog85 »

So, even though I had a spark, it might not have been a strong enough spark? I'll give this a look when I have time again.

Thanks
Aaron
murrayjp
United States of America
Posts: 69
Joined: Thu Jul 19, 2018 6:29 pm

Re: Won't run when hot

Post by murrayjp »

evening all
got a question on keeping the engine cooler.
can one reroute the air cleaner like a 716/8 to get cold from outside the engine compartment.
could a ele. fan be installed to increase air flow across the engine and along with adding one to oil cooler , since the air filter has been rerouted

FLa is too darn hot in the summer and it's summer 9 months a year
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