Is this the dreaded 914 vapor lock?, Asking for your ideas and thoughts |
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Is this the dreaded 914 vapor lock?, Asking for your ideas and thoughts |
Artfrombama |
Jul 14 2024, 05:04 PM
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#1
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Member Group: Members Posts: 156 Joined: 21-January 24 From: Alabama Member No.: 27,870 Region Association: South East States |
Drove my 914 to a PCA function yesterday morning, 93f and humid.
After driving on the interstate at 70-75mph for around 45 miles I exited and the motor died. I had enough momentum and coasted into a gas station/convenience store where I topped off the tank and tried to restart the car, no luck. The car would fire, run a few seconds and die then refused to re-start for another 10-15 minutes then the same scenario again. No tools to diagnose or repair. While waiting on AAA for three hours (another story) I would occasionally try to start the car with the same results. Today, car started normally, runs normally. 1974 L-jet, original three bung fuel pump, original location. 500 miles on new tank, sock, filter, ss lines. |
bkrantz |
Jul 14 2024, 09:00 PM
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#2
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914 Guru Group: Members Posts: 8,056 Joined: 3-August 19 From: SW Colorado Member No.: 23,343 Region Association: Rocky Mountains |
Could the pump itself be causing at least part of the problem? Either weak all the time plus a touch of vapor lock, or weak when over-heated?
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wonkipop |
Jul 14 2024, 09:53 PM
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#3
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Advanced Member Group: Members Posts: 4,611 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille |
Could the pump itself be causing at least part of the problem? Either weak all the time plus a touch of vapor lock, or weak when over-heated? hmmm. having taken one of those pumps completely apart to replace all seals right down to the electrical connection seal they are pretty rock solid. and they get cooled by the fuel passing completely through them. the shutting down while it was still on the run as he came off the ramp might point to something in the pump. they do have a little spring loaded gizmo in the head of the pump that activates on excessive fuel pressure build up in the high pressure line to the injector ring. its possible that might stick in someway and then the pump will just send fuel off via the release line which is the third port. the top of the pump can come off easily without undue worry. there is an o-ring seal which you might have to replace on reassembly but its easily obtained. making sure it a nitrite seal. you can clean out that port and make sure the pressure relief is operating freely. it also has a little rubber nose on the pin which seals it normally after you switch off to hold pressure in the lines. but if it was to jamb open for any reason you certainly won't be able to hold pressure in the high pressure fuel ring. if you take the pump top apart just be careful to note which way the roller cells lie and try and put them back in the same orientation. but somehow i doubt it is the problem. but you never know. EDIT link here to a post i made ages ago tearing down the 3 port pump. gives you an idea of whats in there, what it does. http://www.914world.com/bbs2/index.php?showtopic=350416 |
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