What else could go wrong?

[thecrystal1]

Ok I just went through this whole ordeal to find a cheaper replacement fuel pump for my a8 (pls see prev thread "Fuse Blowing") and finally got a new pump from the dealer. Car works great until I was working on it right now and it died again. Sounds like it's out of gas. Sucks. Anyway I read on another forum that when changing the fuel pump on an a8 that one might have to recalibrate the sending unit for the fuel level. Here's what the guy says:


I have heard of problems associated with fuel not being picked up (even though there is still 1/3rd of a tank left) after replacing the fuel pump. This is now happening on my 4.2 quattro sport. I have taken the pump out and reseated it about 60 times now. I have also had all the venturas/feeds, pump, and accumulator out of the tank and bench tested using a childs swimming pool and it all works fine. Petrol is being picked up from both sides of the tank and eventually the smaller side runs dry but as soon as the fuel guage gets to a 1/3rd full the car stalls and wont pick up the 4" of petrol still in the main tank. Can someone please help. There is only 1 way that the 3 venturies can connect to the pick up due to their length, everything is working outside the vehicle and all is working inside the vehicle if there is over 1/3rd of a tank. Arrghh.

Re: Fuel runs out when 3rd of a tank still left - pump replaced
Posted: Dec 21, 2005 1:53 PM Reply
MAKE SURE THE PUMP IS ALL THE WAY DOWN SEE THE MANUAL. AFTER THAT THERE ARE 2 SIZE A-8 TANKS 80/ 90 LITRE CHECK YOUR VIN THEN GO TO MANUAL AND GET THE VOLTAGE CALIBRATIOS FOR YOUR TANK THEN TAKE THE READINGS FROM EACH OF THE 2 SENDING UNITS. THEN SIMPLY RECALIBRATE THE SENDING UNITS PER THE MANAUL . IE YOU HAVE TO SET EACH SENDING UNIT SEPERATLY THEN AD THE VOLTS TOGETHER TO MATCH THE MANAULS SPECS

The funny thing is that my a8 currently has 1/3 tank left in it. Sounds like this could be the same thing. I'm going to get some gas and put it in and see what happens. If it starts again then I asume this is the problem. The guy on the other forum didn't respond back with anything else after this entry. Does anyone out there know about this? I don't have a manual for the car but will be getting one soon.


Ok, I put 5 gallons in and the car starts right up no problem. I made sure the pump was seated all the way and also the sending unit b4 I put in the gas and nothing happened. After putting in additional fuel, she starts right up.

[jayefen]

This was an interesting read, as i have never heard of this before on any car, why do things have to be so complicated. Glad to hear you got it going, and hope your problem is now solved.