Vapor Lock, Your thoughts? |
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Vapor Lock, Your thoughts? |
dcheek |
Jun 5 2018, 07:12 AM
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#1
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Senior Member Group: Members Posts: 691 Joined: 30-May 06 From: Westfield, New Jersey Member No.: 6,103 |
I took my 914 out for a ride on a very hot and humid day last week. I came back and parked in my driveway which has a slight incline. A few minutes later I had trouble restarting to move the car into the garage. I noticed a girgling sound coming from the tank on the initial spool up of the fuel pump before engaging the starter. The engine would fire but would not continue to run. It sounded like it was not getting fuel. I finally got it to run, and promptly pulled into the garage. The next day I started the car with no problems. My only conclusion was some type of vapor lock situation or a clogged charcoal canister?? Or, maybe the oxygenated fuel?? I've never experienced this problem before. The fuel is fresh. The fuel pump has been replaced, along with the fuel filter. And, my car has the updated (at the factory) fuel pump location up front.
Any thoughts as to why this would happen? Dave |
76-914 |
Jun 5 2018, 02:48 PM
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#2
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,509 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California |
I seriously doubt the fuel pump vapor locked up front. I've been thru 5 o'clock traffic in Las Vegas when it was 105 and didn't vapor lock in my 76. Ron's '73 did however vapor lock, pissing off many a commuter. I suggest you add a fuel pressure gage. I did the first time mine crapped out. (IMG:style_emoticons/default/beerchug.gif)
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ndfrigi |
Jun 5 2018, 03:34 PM
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#3
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Advanced Member Group: Members Posts: 2,933 Joined: 21-August 11 From: Orange County Member No.: 13,474 Region Association: Southern California |
silly answer sir! How much gas you have in ur tank?
I helped a friend 914 after he tried several things how to make it run. after I checked the fuel tank, there is no much gas. Pour a gallon of gas and it started. |
theer |
Jun 5 2018, 03:39 PM
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#4
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Senior Member Group: Members Posts: 677 Joined: 31-July 15 From: Dover, MA Member No.: 19,014 Region Association: North East States |
Fuel pressure regulator?
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iankarr |
Jun 5 2018, 06:15 PM
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#5
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The wrencher formerly known as Cuddy_K Group: Members Posts: 2,481 Joined: 22-May 15 From: Heber City, UT Member No.: 18,749 Region Association: Intermountain Region |
To me, the incline and gurgling noise suggest low fuel level. For vapor lock you need a heat source which “boils” the gasoline into vapor and keeps the pump from pumping. With the pump up front that’s unlikely. The charcoal canister is only to keep vapors from the interior and fuel will leave the bottom of the tank regardless of the condition. I suppose it’s possible that the gas in the fuel rails around the engine could vaporize, but after a few seconds of pumping, fresh gas would make its way in. Another thing to check would be the coil. Heat has been known to make marginal ones worse.
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76-914 |
Jun 5 2018, 06:42 PM
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#6
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,509 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California |
Check the injectors for leak down, also. (IMG:style_emoticons/default/beerchug.gif)
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dcheek |
Jun 6 2018, 05:29 AM
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#7
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Senior Member Group: Members Posts: 691 Joined: 30-May 06 From: Westfield, New Jersey Member No.: 6,103 |
silly answer sir! How much gas you have in ur tank? I helped a friend 914 after he tried several things how to make it run. after I checked the fuel tank, there is no much gas. Pour a gallon of gas and it started. I had 1/2 tank of gas at the time. The coil is an interesting thought. I've have trouble in one of my other cars when the coil got hot and would not fire up the engine. My concern is why there was that girgling sound coming from the tank when the ignition was turned on. Maybe the pressure regulator was jammed (or some other component) when hot and caused the fuel pump to back up and blow back into the tank? Can the pressure regulator jam closed? The suggestion about adding a fuel pressure gauge would let me monitor both cold and hot. If there was a jam it would pin the needle on the gauge. Like I said, I started the car the next morning and it ran fine, so it must have something to do with heat build up. Dave |
saigon71 |
Jun 6 2018, 06:58 AM
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#8
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Advanced Member Group: Members Posts: 2,000 Joined: 1-June 09 From: Dillsburg, PA Member No.: 10,428 Region Association: MidAtlantic Region |
Subscribed to this thread...
I drive a 2056 D-Jet. I've experienced this several times driving in hot conditions, even after relocating the fuel pump up to the front trunk. I've driven somewhere in the summer & parked for a short time. The car is a bitch to start. I've also noticed that the car will drop to an extremely low idle during hot driving conditions. I think it may be more of a "heat soak" condition than vapor lock if the fuel pump is up front. |
TheCabinetmaker |
Jun 6 2018, 07:56 AM
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#9
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I drive my car everyday Group: Members Posts: 8,304 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
I think this has nothing to do with the pump. I would suspect the cht sensor, intake temp sensor, or a leaky injector (including cold start valve) as this has classic flooding symptoms. How's your mileage?
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dcheek |
Jun 7 2018, 05:10 AM
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#10
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Senior Member Group: Members Posts: 691 Joined: 30-May 06 From: Westfield, New Jersey Member No.: 6,103 |
Subscribed to this thread... I drive a 2056 D-Jet. I've experienced this several times driving in hot conditions, even after relocating the fuel pump up to the front trunk. I've driven somewhere in the summer & parked for a short time. The car is a bitch to start. I've also noticed that the car will drop to an extremely low idle during hot driving conditions. I think it may be more of a "heat soak" condition than vapor lock if the fuel pump is up front. Have you tried to find out the cause? If so, what was the procedure? Dave |
saigon71 |
Jun 10 2018, 03:09 PM
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#11
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Advanced Member Group: Members Posts: 2,000 Joined: 1-June 09 From: Dillsburg, PA Member No.: 10,428 Region Association: MidAtlantic Region |
Subscribed to this thread... I drive a 2056 D-Jet. I've experienced this several times driving in hot conditions, even after relocating the fuel pump up to the front trunk. I've driven somewhere in the summer & parked for a short time. The car is a bitch to start. I've also noticed that the car will drop to an extremely low idle during hot driving conditions. I think it may be more of a "heat soak" condition than vapor lock if the fuel pump is up front. Have you tried to find out the cause? If so, what was the procedure? Dave Dave: Here is some interesting reading on the subject. It is a common problem with D-Jet. http://www.914world.com/bbs2/index.php?sho...7465&hl=cht rheostat&st=0 http://www.914world.com/bbs2/index.php?showtopic=298261 From what it looks like, the solution is to run a variable potentiometer in parallel to the CHT so you can adjust it when the engine is hot. |
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