fuel accumulator

[7783911]

last year prior to revamping the oil cooling system (rad and fan in front fender) I experienced difficult "hot" starts a couple of times..hasnt occured since but havnt experienced high engine temps since the redo. I suspect the fuel accumulator may have been a culprit..is there a simple way to test it?

thanks

bob

77 with 83 sc engine

[boyt911sc]

Originally Posted by 7783911

last year prior to revamping the oil cooling system (rad and fan in front fender) I experienced difficult "hot" starts a couple of times..hasnt occured since but havnt experienced high engine temps since the redo. I suspect the fuel accumulator may have been a culprit..is there a simple way to test it?

thanks

bob

77 with 83 sc engine

Bob,

Remove the fuel accumulator from the car and bench test it. These are how I test them on the bench:

• Perform a pressure test using less than 5 psi. while the FA is underwater.
• Another method and more convenient is to do a vacuum test. No need to use water.

There are a few more tricks but try the above first to test and evaluate your fuel accumulator. Keep us posted.

Tony

[7783911]

Tony

could you explain the vacuum test method for me, i have a vacuum test tool but unsure of setup because there are 3 ports

[prschmn]

Another method without removal is putting a gauge on the system
and without the car running crack the bleeder for a sec and see if the pressure
comes back after releasing it. Also pull the bottom line-no fuel should come out of the accumulator-if it does the diaphragm is bad.

[7783911]

being a neophyte re testing with a vacuum gauge, i need to know which port (bottom, top left, top right) to place the gauge on and what to do with the other 2 ports during the test

sorry to be such a dunce

[boyt911sc]

Originally Posted by prschmn

Another method without removal is putting a gauge on the system
and without the car running crack the bleeder for a sec and see if the pressure
comes back after releasing it. Also pull the bottom line-no fuel should come out of the accumulator-if it does the diaphragm is bad.

There will be some residual fuel coming out from the bottom port when you disconnect it. This is not a good test to evaluate a three-port FA. Once a fuel accumulator is used in a CIS, the bottom chamber would have raw fuel. If you don’t believe it, try it yourself.

Tony

[john walker's workshop]

Yeah, They all bleed sufficient fuel out the bottom fitting to get a shop rag dripping wet. A popular improvement is to use the larger, later model accumulator.

[boyt911sc]

Originally Posted by 7783911

being a neophyte re testing with a vacuum gauge, i need to know which port (bottom, top left, top right) to place the gauge on and what to do with the other 2 ports during the test

sorry to be such a dunce

You could test your 3-port or 2-port fuel accumulators for leak several ways:

a). Using a hand vacuum pump:


b). Using positive air pressure:
You could use air compressors, foot pump, or simply blow it using your mouth. I used my breathe to create bubbles in the water.




The bubbles below may not look obvious in the picture, but in actual test the bubbles were very obvious for the presence of leak source.


I’m 79 years old and weighs less than 137 lbs. soaked and wet, so most of you surely would have no problem using this method.

Tony

[7783911]

Thanks Tony....will attempt this weekend if not too cold in the garage