fozsug Posted September 18, 2010 Share Posted September 18, 2010 Just done a service on the disco (1995 300tdi), and on removing the fuel filter, expecting to get covered in diesel as usual, was surprised to see that it was only half full? The car is running well and no signs of any fuel leaks at unions etc, sedimenter is clean, any thoughts? Is my lift pump on its way out? Thanks in advance Tony Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 18, 2010 Share Posted September 18, 2010 Had this problem recently, but the filter was almost empty. Failed lift pump was diagnosed, but not the cause of the air. When the filter is changed - the lift pump primer lever has to be used to expel any air out of the filter/low pressure side of the system. Even if the engine will start, the air will never go and if it's low enough will cause poor top end power/ cutting out/ delayed starting etc. Air leaking into the system from elsewhere, such as pick up or sedimenter filter, still won't collect in the filter housing if the lift pump is working ok. Les. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted September 20, 2010 Share Posted September 20, 2010 Did you bleed the air out of the filter when you got it running? IIRC the fuel is pulled from near the bottom of the filter via a dip-tube. If there is air in the filter it shoudl still run but as said if there is too much it can hamper top end power. Quote Link to comment Share on other sites More sharing options...
fozsug Posted September 20, 2010 Author Share Posted September 20, 2010 Had this problem recently, but the filter was almost empty. Failed lift pump was diagnosed, but not the cause of the air. When the filter is changed - the lift pump primer lever has to be used to expel any air out of the filter/low pressure side of the system. Even if the engine will start, the air will never go and if it's low enough will cause poor top end power/ cutting out/ delayed starting etc. Air leaking into the system from elsewhere, such as pick up or sedimenter filter, still won't collect in the filter housing if the lift pump is working ok. Les. After changing the filter the engine started first time, took for a drive and up a long gradual hill started to loose power . Got it bach and sure enough was still half empty. So primed as you said and tried again up the same hill and this time worse . Got it back and re chect all connections olives unoins , sedimenter filter and seal, all seem ok, sqirted a bit of ether on joints etc but no sign of change. So is it the lift pump??? If so, there seem to be alot of people claiming to do AC delco OE quailty pumps on Ebay, are they worth the risk, or do i just get a genuine OE part? Thanks in advance Quote Link to comment Share on other sites More sharing options...
Les Henson Posted September 20, 2010 Share Posted September 20, 2010 Was there air in the filter after the second, worse attempt? Les. Quote Link to comment Share on other sites More sharing options...
fozsug Posted September 20, 2010 Author Share Posted September 20, 2010 Was there air in the filter after the second, worse attempt? Les. Yes there was, i tried a third attempt, this time filling the filter up with diesel before fitting, anf priming from the lift pump, took up the hill still starting to loose power and splutter, pulled over and checked filter, half empty again. Fitted back on primed and started first time, all the time that the underload rev when driving is under 2800rpm , runs fine, prolonged underload driving over 2800rpm, starts to splutter loose power. On standstill not under load can be reved to 3500 and held there with no problem? Quote Link to comment Share on other sites More sharing options...
disco_al Posted September 20, 2010 Share Posted September 20, 2010 sounds like the lift pump to me, especially with the loss of power above 2800rpm, it can't keep up. Quote Link to comment Share on other sites More sharing options...
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