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Old 05-26-2014, 04:38 PM
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fuel pressure

Is there a way to test the fuel pressure prior to the injection pump? My car was sitting for about three months and now will start but not keep running. I know the filters need to be changed but I am wondering about the pump and filter in the tank.

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Old 05-26-2014, 04:49 PM
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There shouldn't be a pump in the tank. There is a strainer in there that often gets clogged after decades of use. If you have more than a half tank of fuel, you can switch the supply and return lines and see if the car runs any better. If it does, it's time to clean or replace the tank stainer.
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Old 05-26-2014, 04:56 PM
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Quote:
Originally Posted by Phil View Post
Is there a way to test the fuel pressure prior to the injection pump? My car was sitting for about three months and now will start but not keep running. I know the filters need to be changed but I am wondering about the pump and filter in the tank.
It can be done but you have to custom rig a tee to a pressure gauge. An easier way is to measure the volume output of fuel return to tank per unit time. Take the cigar hose off and stick it into a bucket and idle for 30 seconds then measure vol. Someone else can supply the spec for that, IDK what it is off hand.

Sounds like you may have air in your fuel. A clogged fuel strainer /primary /secondary fuel filter could cause the symptoms you are having.
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Old 05-26-2014, 10:08 PM
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Checked mine this morning. Got a spare line from LKQ pick and pull and used the fittings to use with my harbor freight pressure tester. Like others have said on another thread, it is nearly impossible to get an accurate read on pressure because of the violent pulsations from the left pump.

I really wanted to see the actual pressure prior to doing a spring stretch on the relief check valve.

Heard that someone restricted the orifice on their gauge to dampen the oscillations. Might anyone have anything to add on orifice restriction.
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Old 05-26-2014, 10:34 PM
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It is easy to make a restriction in a Fitting.
Fill about 1/4" of the end of a Fitting with JB Weld Epoxy and let it cure properly and after that you are able easily drill what ever size Hole you want into the Epoxy.

See Post #3 for the test specs.
Correcting low internal IP fuel pressure on my 85 300D turbo

If you are going to do the test it is best to do so with a New Fuel Filter so a plugged Filter does not influence the test.

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