Understanding warm start workarounds
08-04-2006, 08:08 PM
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Understanding warm start workarounds
I have the classic warm start symptoms of a faulty accumulator/ check valve in my 78 SC. I am trying to understand which methods are most effective as workarounds until I get the problem fixed.
One suggestion in 101 Projects is, after stopping the engine, turn on the ignition and let the fuel pump circulate fresh fuel through the lines for a few minutes to cool them down. Question: does the fuel pump really circulate fresh fuel through the lines and back into the fuel tank when the engine isn't running, or does it just pressurize the lines to working pressure? Also, is it completely okay for the ignition to be on for a few minutes without the engine running?
Another suggestion is, when the problem occurs, turn on the ignition, open the air box, and fully lift the air sensor a few times to purge the vapor through the injectors. Question: How long do I hold the air sensor open each time, i.e. is the vapor lock usually near the engine, or does it occur further up the fuel line somwhere? Also, do I need to close the air box before trying to start the engine?
It seems to me that the vapor lock is likely to be near the engine, where is hot, not in the fuel pump, which I understand is under the front of the car. If this is the case, wouldn't the fuel pump still make good pressure because it is filled with liquid fuel? Then I would think turning on the ignition and running the pump for awhile before starting should clear the vapor out, especially if the 101 Projects method is real, but it doesn't seem to work this way.
I guess rather than trying to figure it all out, I should just fix the problem...
One suggestion in 101 Projects is, after stopping the engine, turn on the ignition and let the fuel pump circulate fresh fuel through the lines for a few minutes to cool them down. Question: does the fuel pump really circulate fresh fuel through the lines and back into the fuel tank when the engine isn't running, or does it just pressurize the lines to working pressure? Also, is it completely okay for the ignition to be on for a few minutes without the engine running?
Another suggestion is, when the problem occurs, turn on the ignition, open the air box, and fully lift the air sensor a few times to purge the vapor through the injectors. Question: How long do I hold the air sensor open each time, i.e. is the vapor lock usually near the engine, or does it occur further up the fuel line somwhere? Also, do I need to close the air box before trying to start the engine?
It seems to me that the vapor lock is likely to be near the engine, where is hot, not in the fuel pump, which I understand is under the front of the car. If this is the case, wouldn't the fuel pump still make good pressure because it is filled with liquid fuel? Then I would think turning on the ignition and running the pump for awhile before starting should clear the vapor out, especially if the 101 Projects method is real, but it doesn't seem to work this way.
I guess rather than trying to figure it all out, I should just fix the problem...
08-04-2006, 08:42 PM
#2
Team Owner
I thoughtthe pump only ran during cranking via the relay, then after starting using the sensor plate. I would think lifting the sensor plate for any amount of time would risk flooding the engine or diluting the oil .
