Ok, wifey went to pull out of garage the other day (Tues.) and after putting car in gear, boom it went dead.  She started it again and after 2 seconds of sputtering boom dead again.  Tried it when I got home and spun over fine, but no fire.  screamed fuel pump to me, but I did all the little things first, Fuses #7 and #26 or 28 or something like that, both were good. So I proceeded to check voltage at the pump (It is NOT under the back seat as alot of people told me..) it is under the passengers side mat in the back.  I checked the voltages when my wife was cranking the engine and it was 12.5 volts. When the key is just "on" the volts were 3.5...
I went ahead and pulled the pump, not hard - just I had never done it / pumped 12 gallons of gas out....
tested the pump connected straight to a battery with jumpers (6'+), and nada the pump didn't do any thing. reversed the polarity and it clicked, reversed it again and clicked again, after the 4th time it went to buzzing.  I put it back in and nada.
Pump would work sometimes when it was laying on its side.  Good enough for me, new pump ordered.
$260 later... new pump installed and cranked it over, nada.  Cranked it over again and sputter sputter - vrooooom! Yea! fixed.  Well sorta... Read on.

Car started up immediately after shutting it off when testing - turned car over to wifey (after flushing brakes and replacing front pads with those niffty green ones from England...)
OK here is the point to this diatribe:
Car's fuel pump isn't firing with the switch "on".  it is pumping when the key is switched to "start", and it runs when the car is started.  So you have to crank the engine to "prime" the fuel rail.  The second time you crank it, it fires right up.
The 3.5 volts is a concern.
Car accellorates well after started but the double cranking cannot be good on the engine's starter. The fuel drain happens sometime after the car has sat for 15+ minutes.  If you shut the car off, then wait up to 15 minutes (all I have had time to sit still and check) the car will fire right off. I just don't know what to check now.  Could the relay be bad?
How many items can cycle the fuel pump? Obviously the cranking and a signal from a running engine, but when the key is "on" shouldn't it cycle and prime the system?
OR is the pressure regulator leaking down and allowing the stored pressure on the fuel rail to release back to the tank?
I appreciate all and any help!
Thanks, KC

Check faults also,  the pump will not run with just the key on,  it should prime when u open the drivers door and for just a sec when you turn the key on

So if I understand correctly there should be 12V sent momentarily when the Drivers door is opened.
The Fuel pump was sourced at the FLAPS and is a VDO unit, it has had the Audi Rings milled off, but otherwise has all the same part #'s and marks as the unit that was removed.
What is the trigger for this momentary 12V surge related to the door, is it the CCM?
I am just wondering if there is a fuse or relay for this system that is blown.
The unit seems to be working otherwise.
I do not think it is the pump.
I used to hear the whirring for a moment when I opened the door now that I think of it...
I'll hook up the multi-tester to the harness and let the wifey open the door for me, what is the cycle time to wait between opening the door to set up the equipment and the opening for the test?
Thanks in advance and I appreciate all the help.
KC

I just love electronics.  Drive a Bug. When it quits you just go back and pick up the pieces. No guess work  Problem solved.

You missed the part where I said this is my wife's car.
She has not ridden in an ACVW since BAP 10. 
KC

Quote from: ASBug on June 25, 2012, 02:54:40 PM

Quote from: Ret.Bugtech on June 25, 2012, 08:58:47 AM

I just love electronics.  Drive a Bug. When it quits you just go back and pick up the pieces. No guess work  Problem solved.

You missed the part where I said this is my wife's car.
She has not ridden in an ACVW since BAP 10. 
KC

That's probably because they don't stop long enough for her to get in before it's on to the next owner!!!!

So, I obviously wasn't the only one thinking that....

 

 

Quote from: Ret.Bugtech on June 25, 2012, 08:58:47 AM

I just love electronics.  Drive a Bug. When it quits you just go back and pick up the pieces. No guess work  Problem solved.

You missed the part where I said this is my wife's car.
She has not ridden in an ACVW since BAP 10. 
KC

The one thing I have learned over the years is to put the Wife in a car that is very reliable( a old Passet aint one of them) and you don't know how to work on it. .  If it screws up take it to someone that knows how. Mama is happy ,I'm happy and she doesn't burn my biscuits and I get to go play instead of working all day on the stupid car.

The trigger comes from the door lock module, then to the ccm, then to the Ecu, then to the fp/engine electronics relay, number 429 I think (don't hold me to it im shooting from the hip) then out the fuse to the pump.

Do you have issues with the door not unlocking all the time or randomly locking itself?

The trigger comes from the door lock module, then to the ccm, then to the Ecu, then to the fp/engine electronics relay, number 429 I think (don't hold me to it im shooting from the hip) then out the fuse to the pump.

Do you have issues with the door not unlocking all the time or randomly locking itself?

Sal,
I have not noticed it locking weird, other than my fob seems weak, will only open from right near the car even with new batteries.  My wife's fob is great though.
I do not drive the car any more, but will ask my wife about any strangeness with the locks.
Is relay 429 specific just to the FP when the door is opened or is it utilized when the car is cranking and running...
I appreciate all the help, and contrary to David's omens, we like the car.
Sal, I think I came by your house once to look at a swallowtail 4 door you had, I was in a white beetle (autostick), was that you ?
KC