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Discussion Starter · #1 ·
Help I changed the fuel filter after being dogged by constant rough running.Car is now refusing to start.Ran a diagnostics check with no stored codes coming up.There is no electric pump on the car just a mechanical pump driven from the cam shaft.I am starting to think the lift pump is away.Is there any way of testing this.

Its a 3 cyl 02 1.4tdi AMF.I have changed the fuel filter many times before and never had this happen.I have cranked the engine till the bat is about flat nowt.I have pushed the diesel through using an electric pump and still nothing.I did this using the flow and return at the tank.I even monitored the return using a glass to make sure all the air was out before reconnecting the fuel lines.When the lines were full I tried cranking again to no avail.I have spoke to Audi and according to them there is a mechanical pump on the end of the rocker cover taking its drive from the cam.I have checked this out and there is some kind of pump with two fuel lines going to it.I have traced these lines by eye to make sure they are actually fuel lines.There does appear to be some sort of switch/sensor in the line just before this pump.I was wondering if this some sort of crash cut off type switch.Hope some of this info helps.Cheers Davy
 

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Are you sure that the filter is full? It's some coincidence if it's decided to go at the same time as you did the fuel filter. Check the fuses too. There is a pump on the fuel tank, supplying it to the tandem pump which is on the crank which then supplies each injector. I'd check fuses first. Then I'd make sure fuel pump is full, and crank again. I'd say there is more chance of an air lock.
 

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Ps I think that switch by the pump might be a relay. Will check when I'm at the laptop tomorrow eve.
 

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Could be a blocked faulty fuel filter we have had these before with transits and the same thing on mini oil filters bringing on the oil pressue light because the filters were a faulty batch
 

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Discussion Starter · #5 ·
Hi guys and thanks for the responses, I have searched high and low for an electric pump at the tank I even pulled the sender unit out thinking it might be in there,no joy.There are no fuses in the fuse box although marked there are no connections or wiring at the back.The only thing I could find was the tandem pump on the cam.I decide to start again and stripped the filter out and closely examined everything and still could find nothing wrong the only thing it could have been was the o ring at the filter housing so I replaced it just in case. I rebuilt and split the fuel line return under the bonnet, and using a vacuum pump I drew the fuel through to the engine then went to the tank and again drew the fuel through on the return to the tank.At this point I was starting to get signs of life. I decided to tow the car to a local garage using a mates landrover. While being towed I stuck the car into gear and after about half a mile it started.Was it the o ring or an air lock your guess is as good as mine.The car now starts and runs normally and after all that the miss that caused me to change the filter is still there.With no stored codes I am starting to look at the lift pump as a potential problem area.Thanks again Davy
 

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I'm not sure on the 1.4 3 cyl engine to be honest but that washer could of been preventing enough vaccuum for the suction of the fuel or an air lock. Hard to know. Glad you got it working!
 
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