checking fuel filter.

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Old 01-22-2017, 07:38 AM
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checking fuel filter.

Is it fair to assume that my filter is clogged when I turn over the engine and fuel does NOT come out of the filter with the uphill line disconnected. I was able to disconnect the rear line from filter and fuel DID pump out of line when I cranked it over.
Been dealing with a crank no start, I'm in the process of trying to test my CPS properly but not sure if I'm testing it right.
Thanks all

2000 f 150 4.2 v6 232,000 miles
 
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Old 01-28-2017, 09:55 AM
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It's unusual for a filter to clog to the point that when it's output is disconnected and you crank the engine ..no fuel comes out.

Do you have a fuel pressure gauge you can install on the input to the filter?

I wonder if the fuel pump is about to go out and can't generate the needed pressure to over come the filter resistance.

Also, maybe the sock on the pickup tube to the pump is clogged.

Good luck and let us know what you find.
 
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Old 01-28-2017, 11:39 AM
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Originally Posted by lee
It's unusual for a filter to clog to the point that when it's output is disconnected and you crank the engine ..no fuel comes out.

Do you have a fuel pressure gauge you can install on the input to the filter?

I wonder if the fuel pump is about to go out and can't generate the needed pressure to over come the filter resistance.

Also, maybe the sock on the pickup tube to the pump is clogged.

Good luck and let us know what you find.
Thanks for the advice lee.I will look into the fuel pressure, I'll have to get a gauge but right now im trying to test crankshaft sensor. I've tested it for ohms key on and off. My truck is currently throwing a 1309 code, misfire detection from pcm. Thanks I'll keep you posted
Fuses and relays are good.

2000 f 150 4.2 v6 232,000 miles
 
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Old 01-29-2017, 01:17 PM
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Checking fuel pump with jumper wire from positive battery post with key on.....should I be able to hear pump run?
All I get is a little trickle of spark when I make contact with jumper to pump wire
Thanks.

2000 f 150 4.2 v6 232,000 miles
 
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Old 02-05-2017, 09:41 AM
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*****,
To be honest I'm not sure... usually on "some" makes/models you can hear the pump "buzz" for a few seconds when the key is first in the run or crank position. Some you can't though.

Best way is to disconnect fuel line where ever is convenient, at filter, or fuel rail, or where ever. Then have someone turn the key to run and/or crank position. You should get a nice "spray" of fuel as electric fuel pumps can put out upwards of 50PSI. Becareful of the great fire hazard while doing this. If you get no fuel, or weak stream, I would think it's the pump, filter, pump pickup screen clogged.

What value did you get on the Crank sensor? I believe it should be the same no matter key position.
 
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Old 02-06-2017, 07:18 AM
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Originally Posted by lee
*****,
To be honest I'm not sure... usually on "some" makes/models you can hear the pump "buzz" for a few seconds when the key is first in the run or crank position. Some you can't though.

Best way is to disconnect fuel line where ever is convenient, at filter, or fuel rail, or where ever. Then have someone turn the key to run and/or crank position. You should get a nice "spray" of fuel as electric fuel pumps can put out upwards of 50PSI. Becareful of the great fire hazard while doing this. If you get no fuel, or weak stream, I would think it's the pump, filter, pump pickup screen clogged.

What value did you get on the Crank sensor? I believe it should be the same no matter key position.
Lee thanks for the help. I'll check that # for the sensor. I don't think the #s are correct.
As for the pump. There would be times when I could hear it but most of the time I don't and this has been the norm for 16 yrs.last winter I was experiencing the same crank no start issue for a few weeks, made it through the summer till I recently blew a brake line. After servicing the brakes the truck started right up. But now it won't start. I'm just a back yard novice so I've been trouble shooting this for a couple mos. Googling everything.
Thanks again

2000 f 150 4.2 v6 232,000 miles
 
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Old 02-06-2017, 07:21 AM
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Using jumper wires from the crank sensor (harness side) my readings are.
Ac volts. Btw 1.2 @1.5
Ohms Btw .9@1.5
Both while cranking over.
Should I be using back probes into connector for accurate readings.

2000 f 150 4.2 v6 232,000 miles
 
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Old 02-06-2017, 01:13 PM
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