ATD Cutting out and struggles to start again

maaaxm

New member
Joined
Dec 19, 2014
Location
lowestoft,suffolk
TDI
AGR, AWX, ATD, AAZ, SB, RA
Hi

Recently bought the other half a 2003 beetle tdi pd100 engine code ATD 110k miles. Unfortunately on route home it decided to cut out.

I managed to get the car stated again with leaving the lift pump priming with the ignition on and eventually it came back to life with a bit of throttle and then proceeded to run faultless for around another 10 miles.

Scanned it and it only shows 1 fault (fuel pump relay) which is explained below.

Symptoms.

1. Drives fine and after 10 miles the engine progressively struggles or slightly misses and lacks power as if its about to cut out. (like fuel starvation) then dip the clutch the engine cuts out or eventually just dies
2. Takes ages cranking over to start again
3. Happens after around 10 miles (cold and warm)

Ive only 1 fault code stored which is relating to the fuel pump relay (open circuit) and investigated further and found a secondary relay wired in for the fuel pump which is would explain the open circuit but i believe this is no longer an issue as i can hear the fuel pump running with the ignition on but this does not stop like in my other pd130 once its reached pressure.

Ive changed a few parts so far such as the relay 109 which controls the power to the ecu etc with no change and also changed the fuel filter and air filter.

I'm considering change the crank sensor next and the lift pump if its not able to flow enough fuel to the filter then probably onto the injector wiring.

what I'm interested to know is what controls the lift pump in the tank when turning the ignition on? what regulates the pressure and cuts the pump out when pressure is reached?

any other suggestions would be great.

Thanks
 

k_pt

Veteran Member
Joined
Oct 13, 2017
Location
pt
TDI
VW MKIV TDI
Hi
Recently bought the other half a 2003 beetle tdi pd100 engine code ATD 110k miles. Unfortunately on route home it decided to cut out.
I managed to get the car stated again with leaving the lift pump priming with the ignition on and eventually it came back to life with a bit of throttle and then proceeded to run faultless for around another 10 miles.
Scanned it and it only shows 1 fault (fuel pump relay) which is explained below.
Symptoms.
1. Drives fine and after 10 miles the engine progressively struggles or slightly misses and lacks power as if its about to cut out. (like fuel starvation) then dip the clutch the engine cuts out or eventually just dies
2. Takes ages cranking over to start again
3. Happens after around 10 miles (cold and warm)
Ive only 1 fault code stored which is relating to the fuel pump relay (open circuit) and investigated further and found a secondary relay wired in for the fuel pump which is would explain the open circuit but i believe this is no longer an issue as i can hear the fuel pump running with the ignition on but this does not stop like in my other pd130 once its reached pressure.
Ive changed a few parts so far such as the relay 109 which controls the power to the ecu etc with no change and also changed the fuel filter and air filter.
I'm considering change the crank sensor next and the lift pump if its not able to flow enough fuel to the filter then probably onto the injector wiring.
what I'm interested to know is what controls the lift pump in the tank when turning the ignition on? what regulates the pressure and cuts the pump out when pressure is reached?
any other suggestions would be great.
Thanks
Check the flow of lift pump, 3lts/min. Lift pump works for 1 or 2 secs on ignition, you should hear that, when the engine is on, it's always working.

Don't bother changing the crank sensor, it's fuel related, not electric.

I think there is another relay to activate lift pump, check the wiring diagram.

You should check the voltage on the lift pump too.
 

maaaxm

New member
Joined
Dec 19, 2014
Location
lowestoft,suffolk
TDI
AGR, AWX, ATD, AAZ, SB, RA
problem solved...

after taking a visit to the local breakers to get a replacement lift pump to try i noticed how the fuel pipes naturally lie when not connected to the lift pump connectors (lift pumps removed to drain fuel)

blue at the front and black at the back. mine were the opposite way round.

swapped them over and were all good. (Not my doing i would add)

thanks for the reply but its been good as gold since purchasing it and a 120 trip back in 10 miles stages.
 
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