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76 cis trouble
I may have ran the car out gas. The fuel gauge was showing a quarter of a tank,I have never ran it that low before,anyways went to start it and it would not start ,I checked to make sure I had spark first, it did.I then noticed how low the fuel level was so I kinda figured fuel gauge was inaccurate. I got my wife to crank the starter while I sprayed fuel into air box ,the car hit,and tried to start .so I went and got 5 gal of gas and put it in.still would not start after that so I was looking through my Haynes manual,and found info about air in the fuel line ,and how to bleed it off by turning on ing. And opening flapper inside air box for 5 seconds .I did thi s procedure and the car started right up.I drove it approx.5 miles and parked it. Today I tried to start car and it failed to start,but it will hit if I spray fuel into intake.after researching my manual some ,I've come to think I have a bad fuel pump or the plunger is stuck,could someone please tell me where the plunger is and how to go about repairing it .my Haynes manual does not really tell me where the control plunger is ,unless I'm just not understanding it correctly,and also I need to know the easiest way to check if fuel pump is bad,from what I've read and the symptoms my car has I believe it's one of the two . I really don't want to replace the fuel pump if it's something imay be able to repair myself ,like the control plunger which icant even find ....please help
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11-23-2011, 01:35 PM
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The control plunger is moved by the arm on the flapper when you lift it. How long have you owned the car? Running low on fuel with a dirty gas tank can suck a lot of debris into the filters. Is the fuel tank clean or rusty? Has the filter in the tank or in the engine compartment been changed? You would need a set of gauges to check the fuel pressure. My 1973 does not use a fuel pump relay, but later models did. I'm not sure when the change occured.
Here is a link that explains the cis fuel system. CIS Primer for the Porsche 911
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Ed 1973.5 T |
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11-23-2011, 02:24 PM
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Join Date: Oct 2005
Location: Capistrano Beach, Ca.
Posts: 7,235
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Quote:
You may also have a problem with the cold start valve or its connections. Your car should fire up, though it may not continue running, if the CSV is operating correctly. However, if the fuel system is not pressurized (by the fuel pump) it will not work properly. You may have a loss of residual fuel pressure due to a bad check valve in the fuel pump, a bad fuel accumulator, or a leak in the fuel distributor pressure relief valve. Checking these components will require a fuel pressure gauge set. In short, do some more checking and get a pressure gauge set. Your problem came on suddenly and does appear to be a fuel delivery problem but it may not be a costly fix. The pump is certainly a suspect and will likely need testing, again, with a fuel pressure gauge set.
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L.J. Recovering Porsche-holic Gave up trying to stay clean Stabilized on a Pelican I.V. drip Last edited by ossiblue; 11-23-2011 at 06:30 PM.. |
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11-23-2011, 06:25 PM
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i have checked and replaced relay ,i got my pelican order in after posting for help,so i just changed fuel filter installed new rotor button.before i hooked the exit side fuel line on the filter i had my son crank over the engine,it took about 10 secounds of cranking before fuel started pouring out of filter.next i hooked fuel line to filter and primed system .i thought i heard the fuel pump making a rattle/grinding noise,i turned key off ,back on and slowley raised flapper in air box ,i heard this spray fuel and bleed system.at this point i think problem solved it was a dirty filter ,istarted the car and it ran for about 7 secounds,would not start ba k i tried to prime system again using flapper ,it did not make the noise this time . this leaves me to believe the fuel pump is bad.can any one tell me if pump goes bad will make alot of noise and sometimes work or do they just quit working alltogether ????
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11-23-2011, 07:57 PM
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Join Date: Oct 2005
Location: Capistrano Beach, Ca.
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L.J. Recovering Porsche-holic Gave up trying to stay clean Stabilized on a Pelican I.V. drip |
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11-24-2011, 08:59 AM
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While it sounds like the pump is having issues, have you checked the tank and fuel line from the tank to the pump for rust and debris? You can see inside the tank by removing the level sending unit from the top of the tank. Besides the fuel filter in the engine compartment, there is a screen that goes into the tank. The fuel pump can't pump if the fuel has trouble getting out of the tank. To change this you would need to have the tank nearly empty.
Pelican Parts - Product Information: 911-201-141-00-OEM
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Ed 1973.5 T |
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11-24-2011, 10:30 AM
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The car only has 65 k on it,the tank looks good the fuel filter I took off looked good .could someone please tell me why whenever I push up on flapper in air box the red light goes off on my MSD box? And also should it spray fuel every time push flapper with key in the run position? Or will it only spray if the fuel pump is good
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11-24-2011, 12:24 PM
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Jump 87a & 30 on the fuel pump relay and your fuel pump will run with the key on. Let your pump run for a few minutes and the lift up on the fuel distributo arm and you will hear the injectors. If you don't your fuel pump is bad or you have trash in your tank. I have a76 and have been through this before
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1976 Targa 911S 2.7 Yellow 
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11-24-2011, 03:49 PM
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when you jump 87a 30 do you just insert the wire in the holes ,or do you insert wire and put reley in with jumper?
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11-24-2011, 06:19 PM
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Join Date: Jul 2008
Location: OK
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just put the wire in
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76' 911s Signature Edition |
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11-24-2011, 06:29 PM
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Remove the relay and place the jumpers on the relay plug. The fuel pump should run when you turn the ignition on. Fuel should run though the fuel distributor and return to the tank without the car running. Do not push up on the fuel distributor arm too much or you will dump a lot of fuel in the cylinders. If you hear the pump you should have pressure. Pull the line off after the filter and flow some fuel into a container to check the output. If you do not have out put the pump is most likely bad.
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1976 Targa 911S 2.7 Yellow
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11-24-2011, 06:32 PM
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Just did it ,nothing happened at first ,I crawled under the car and hit the fuel pump with ihe palm of my hand and it started running,I then purged the injectors via the flapper ,car started right up smoked a little and idled fine ,I ran it for about 5min shut it off and it would not start back by itself. The pump will run if you hit it a couple of times with your palm .the pump sound fine when it runs it just won't run with out tapping on it first .I am now looking to see if there is a faulty connection ,doubt it though ,when I took the plate off to acess the fuel pump every thing looked like new ,I don't think this car has been driven in the rain in it's life ,it's crazy this car looks better underneath than it should .
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11-24-2011, 07:01 PM
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The fuel runs right though the electrical part of the pump. If your connection is good you have debris in your pump. Run some fuel cleaner through it if you can keep it running. Most likely you will need to replace it.
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1976 Targa 911S 2.7 Yellow
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11-24-2011, 07:28 PM
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The Other Woman
