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914World.com _ 914World Garage _ So I think I have vapor lock
Posted by: oldschool Feb 12 2014, 10:33 PM
Can Vapor lock happen even while your at a stop light?
I made a few stops today and every time I tried starting my car it just took longer to fire? and when it did, it died down the street at a light. 
Posted by: JStroud Feb 12 2014, 11:04 PM
When I was on my trip last year my car vapor locked at least 8 times....three times while sitting at a stop light, five times died while driving at slow speed.
Mostly after freeway driving then getting stuck in stop and go traffic in town, but then it was 100+ each time.
Not fun though, so during my conversion the new fuel pump is going up front.
Jeff
Posted by: oldschool Feb 12 2014, 11:45 PM
When I was on my trip last year my car vapor locked at least 8 times....three times while sitting at a stop light, five times died while driving at slow speed.
Mostly after freeway driving then getting stuck in stop and go traffic in town, but then it was 100+ each time.
Not fun though, so during my conversion the new fuel pump is going up front.
Jeff
Yeah it never did it before I wonder what changed
I don't have the HE hook up to the heater valves could that be a problem?
Posted by: Dave_Darling Feb 13 2014, 12:00 AM
I've only had it happen once in a couple of decades of driving. That was going through the Desert in 100+ degree temps up a long hill.
I think it is more likely to be a mixture problem of some kind than vapor lock.
--DD
Posted by: KELTY360 Feb 13 2014, 12:09 AM
Maybe your fuel pump is dying.
Posted by: Elliot Cannon Feb 13 2014, 12:27 AM
My fuel pump has been in the back for 10 years. What is vapor lock??
Posted by: euro911 Feb 13 2014, 02:31 AM
Check your fuel filter(s), Jaime.
Posted by: oldschool Feb 13 2014, 10:34 AM
The kid is coming over today to check it out. News at 11 
btw its 1973 2.0 FI
Posted by: SLITS Feb 13 2014, 12:05 PM
There was this blond that married a truck driver ...
On their wedding night, he demanded she get on her knees and blow the meat whistle ....
When nothing came of it, he declared he must be vapor locked ...
That's what it is like.
Posted by: JawjaPorsche Feb 13 2014, 02:19 PM
My first vapor lock was in the desert in 100+ heat then it just vapor lock at red lights, while driving, etc.
Moved my fuel pump to the firewall 20 years ago and it has never vapor lock since! 
Attached image(s)
Posted by: '73-914kid Feb 13 2014, 02:20 PM
Jaime's possible vapor lock issue is something unique I think. He doesn't have heater valves on his heat exchangers, but they're hooked up to the fan shroud, so it hot air directly from the heat exhcuangers is being dumped directly onto the fuel pump..
Posted by: JawjaPorsche Feb 13 2014, 02:24 PM
Jaime's possible vapor lock issue is something unique I think. He doesn't have heater valves on his heat exchangers, but they're hooked up to the fan shroud, so it hot air directly from the heat exhcuangers is being dumped directly onto the fuel pump..
He said it does it a lot at red lights. No air moving except hot air from exchangers. Not good!
Posted by: '73-914kid Feb 13 2014, 03:05 PM
Oh, and we started the car this morning with no issue..
Posted by: 914_teener Feb 13 2014, 05:22 PM
I've only had it happen once in a couple of decades of driving. That was going through the Desert in 100+ degree temps up a long hill.
I think it is more likely to be a mixture problem of some kind than vapor lock.
--DD
+1Check the MPS on vaccum.....could be starting to break.
If you think it might be vapor lock get a sealed fuel gauge at HF and mount it inline to be sure. Try to replicate the problem.
My two cents.
Posted by: 914_teener Feb 13 2014, 05:24 PM
......ohhhh....and make sure your meat whistle is clean! 
Posted by: KELTY360 Feb 13 2014, 06:18 PM
http://www.youtube.com/watch?feature=player_detailpage&v=ErhuKFwKiiQ
Posted by: MDG Feb 13 2014, 06:25 PM
There was this blond that married a truck driver ...
On their wedding night, he demanded she get on her knees and blow the meat whistle ....
When nothing came of it, he declared he must be vapor locked ...
That's what it is like.
Posted by: Kirmizi Feb 13 2014, 08:26 PM
Jaime's possible vapor lock issue is something unique I think. He doesn't have heater valves on his heat exchangers, but they're hooked up to the fan shroud, so it hot air directly from the heat exhcuangers is being dumped directly onto the fuel pump..
Connect the rest of the ducting of the heating system to control the flow of hot air from the HEs.
IIRC the Porsche suggested removing the caps from the passenger side heater valves in order to vent heated air away from the fuel pump.
Posted by: oldschool Feb 14 2014, 01:34 AM
I'm going to put back the heater valves..that should do it. 
Posted by: The Cabinetmaker Feb 14 2014, 06:44 AM
The heater valve, when in the closed position, just dumps the hot air. It dumps directly on the pump which is only about 2 inches away. Leave the valve off and cap both tubes. My 73 used to have vapor lock anytime it got above 95. Moving pump to front trunk solved that problem forever.
Posted by: Dave_Darling Feb 14 2014, 10:11 AM
Or put a hose onto the valve and run it somewhere else than straight at the fuel pump. That was evidently a factory-specified retrofit for dealers to do when vapor lock was encountered.
--DD
Posted by: oldschool Feb 14 2014, 10:53 AM
When I first got my car (from the org owner) It never had a problem, But after a few mods. So before I move the pump I'll try putting everything the way it came.
and thanks for all the help.
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