# How to Test / Check Fuel Pump Check Valve



## murphysf (Jun 15, 2009)

Wanted to know if there were any clever ways of checking the Fuel Pump Check Valve. 

The fuel system pressure seems to dop a good bit after it sits. Returning to the car 15 minutes or so after it has been running the car sumbles upon startup for a few seconds. I figure that the fuel pressure is building back up. 

I recently swapped out an injector. The car was off for about a half an hour, I disconnected the fuel line to the injector and expected a small amout of gas to squirt out, but none the pressure already dropped. 

In addition to the Fuel Pump Check Valve I also suspect a bad Fuel Accumulator. I know everyone says that they rarely fail, but years ago I had similar problems for over a year and finally replaced the Fuel Accumulator and the car started fine hot or cold. The other items I suspect that might be leaky are the injectors or cold start valve. Am I missing any other areas to check for leaks?


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## antichristonwheels (Jun 14, 2001)

put on a new one 

IF it runs good, the old one was bad


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## WaterWheels (Aug 14, 2005)

murphysf said:


> In addition to the Fuel Pump Check Valve I also suspect a bad Fuel Accumulator. I know everyone says that they rarely fail . . . The other items I suspect that might be leaky are the injectors or cold start valve.


 The check valve is maybe the hardest of all the possible things to replace, not work hard but mess and possible other things breaking while doing the work. I would save it for last if everything else checks out. The accumulator can go bad by having a tear/hole in the diaphram. This is most often discovered by removing the screw which sits at the end of the housing, if it is dry then things are OK, if fuel comses out it is bad. I guess the spring inside could become weak but that would take a long long long time I believe. 

A leak in general, as in fuel seeping from a connection or a hose. The cold start valve as you suggest. One or more fuel injectors or even a bad seal under the fuel distributor metering pin. Any place that fuel can find a way out needs to be looked at, is it CIS-e? If so the fuel pressure regulator has a screw to adjust the residual pressure, and *should only be touched if there is a problem like this one!*


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