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  #1  
Old 09-24-2009, 04:31 PM
Karma50's Avatar
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Join Date: Nov 2007
Location: Lewisville, Texas
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Fuel Pump Volume Test?

I have been searching the archives for a solution to my fuel supply problem.

My fuel filters needed changing pretty bad by the time I replaced them and after I did it worked for a day then clogged again. Could that be the case? I let the car sit for a while until last week when I started her up she ran fast! But I let the fuel tank get pretty low before I filled up and again the filters seemed clogged.

I am assuming filter because if I put it in Park and push the pedal to the floor (is it called a "gas pedal" on a diesel?) it takes a good 5-7 seconds to get the RPMs up to the 3000 range. So on the road the transmission shifts so early, there isn't any torque and she does 0-40 in about 20 seconds! It also is hard to start a cold engine.

I read in a recent post a reference to a "Pump Volume Test". But I cannot find an explanation. There are only 4 references and all seem to presume the reader already knows what one is.

Should I change the filters again or do a pump volume test? And how do you do a pump volume test?

Aaron

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  #2  
Old 09-24-2009, 05:34 PM
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Location: Valle Crucis, NC
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Those are filter symptoms, for sure. If you have a goo problem in your tank, it's possible to plug a filter in a day. I know, because my 240 has plugged two in one day on me before. 5 seconds to 3k rpm at full throttle is DEFINITELY too slow for one reason or another.

There's a strainer in the bottom of the fuel tank that could be plugged up, causing filter-like symptoms. It bolts in from the bottom at the underside of the car, opens up a hole in the tank when you change it thus necessitating the draining of your fuel first, and takes a socket or wrench bigger than any we own to take out. We ended up having to take the whole darn tank out and then using channel-lock pliers on the strainer bolt head.

But anyway... check your throttle linkage. If it's slipped out of adjustment or come loose or something, that might explain the lack of full throttle response.

Pump volume test, if i remember correctly (which I might not) is a way of determining if your injector pump is delivering "enough" fuel or if it has become so... worn out?... that it's not providing enough fuel to the engine. if it's what I *think* it is, the test is simply taking the fuel return line loose under the hood, running the engine for a specified number of seconds at a certain RPM, and measuring the quantity of fuel that is dispensed into your catcher. If it's too little, you have an IP problem. What the numbers are, I don't know. I've actually been looking for them myself and those threads seem to be QUITE elusive.
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Old 09-24-2009, 09:24 PM
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Location: Boondocks
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Get your tank cleaned and your lift pump cleaned as well.

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