east coast ramble
09-08-2003, 10:03 AM
#1
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east coast ramble
Just got back from the ramble - what a blast!!!
Ok I have a question ~~~~~~~~~
I have searche the wiring over and pver and have never gotten an answer for this on my own.
I have a '74 L-Jet engine. The problem that Is eem to be having is the fuel pump. It is my understanding that it should always be on when the ignition is on, even when the engine is not running. However, sometimes I cannot get mine started without manually turning it on. I do this by putting in my old air flow snesor and cranking open the valve enough to trip the contacts and trigger the fuel pump.
I guess my question is, what exactly should happen? Is it in fact true that the fuel pump should come on with ignition and always stay on?
What would cause it not to come on? (Best guess)
Anyway,
Thanks guys for all the help and encouragement at the meet
- Mike Murphy
Duxbury, MA
Ok I have a question ~~~~~~~~~
I have searche the wiring over and pver and have never gotten an answer for this on my own.
I have a '74 L-Jet engine. The problem that Is eem to be having is the fuel pump. It is my understanding that it should always be on when the ignition is on, even when the engine is not running. However, sometimes I cannot get mine started without manually turning it on. I do this by putting in my old air flow snesor and cranking open the valve enough to trip the contacts and trigger the fuel pump.
I guess my question is, what exactly should happen? Is it in fact true that the fuel pump should come on with ignition and always stay on?
What would cause it not to come on? (Best guess)
Anyway,
Thanks guys for all the help and encouragement at the meet
- Mike Murphy
Duxbury, MA
09-08-2003, 01:42 PM
#2
R.I.P.
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Murph....unfortunately I don't have any answers, but I did want to welcome you to RENNLIST, (the worlds largest Porsche Forum) and agree with you. The ECR was really a blast! 
09-08-2003, 09:21 PM
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Hi Murph....it was nice to meet you at the ramble...glad you had a good time...I bet you'll talk about the ride in JD's car for a long time 
On to your problem...The L-jet fuel pump will run while the starter is engaged or when the flap in the AFM is moved. So it should come on when you start cranking, then the flap will move to keep the pump running as the engine starts. A vacuum leak will keep the flap from moving enough to keep the engine running.
On to your problem...The L-jet fuel pump will run while the starter is engaged or when the flap in the AFM is moved. So it should come on when you start cranking, then the flap will move to keep the pump running as the engine starts. A vacuum leak will keep the flap from moving enough to keep the engine running.
09-08-2003, 10:04 PM
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well - I got it going and it seems fine. I have thought about it and I think that because my hose that connects the throttle to the air flow sensor is soooooooooo worn out that the air it needs to start is taken through the cracks and holes. The other possibility is that the pump does not always come on with the starter. I guess next time i am having problems I should disconnect the starter solenoid and see if it kicks in.
As for the vacuum leak ~ Is it possible that the advance is worn out and leaking vacuum? When I put my head in their I can hear something hissing, which I think is vacuum, but may be something else too. Sounds kinda like it is coming from the air plenum. So I am thinking intake runner boot, vacuum advance on the distributor, small vacuum line to distributor or larger hose under that one. But I checked all of these and they all seem tight and in good condition. Pelican suggested to me a while ago that I spray small amounts of starter fluid near suspects and nothing, not one change in rpm or anything.
So I am on to look further. I really do not know what is up with this problem, I have had leaks since I got the car and am always replacing these hoses and sensors that have worn out to the point that everything is pretty much new in their.
My next job is to install a better condition wiring harness for the FI and a new brain. Hopefully this will help with the intermittent problems.
Sorry about the long post!!!!!!!!!!!!!!!! ~ Remind at Watkins Glenn and I will give you a cookie for reading this
- Murph
As for the vacuum leak ~ Is it possible that the advance is worn out and leaking vacuum? When I put my head in their I can hear something hissing, which I think is vacuum, but may be something else too. Sounds kinda like it is coming from the air plenum. So I am thinking intake runner boot, vacuum advance on the distributor, small vacuum line to distributor or larger hose under that one. But I checked all of these and they all seem tight and in good condition. Pelican suggested to me a while ago that I spray small amounts of starter fluid near suspects and nothing, not one change in rpm or anything.
So I am on to look further. I really do not know what is up with this problem, I have had leaks since I got the car and am always replacing these hoses and sensors that have worn out to the point that everything is pretty much new in their.
My next job is to install a better condition wiring harness for the FI and a new brain. Hopefully this will help with the intermittent problems.
Sorry about the long post!!!!!!!!!!!!!!!! ~ Remind at Watkins Glenn and I will give you a cookie for reading this
- Murph