I,m in Sicily getting ready for tomorrow's Time attack event and have an issue which I thought was sorted
TT dies after an hour's run with low voltage 30 intermittent on vag-com. Re starts after 5 mins.New battery, fuel pump relay, replaced in line fuel pump. On climate control on 20 voltage reading 13 to 13.5 V. When i load the system with a/c on starts falling below 13 V and upsets the fuel pump and relay must shut the car down.
Battery re-located to luggage compartment and has been ok with this system for 3 years. Nothing lose from starter ground and had strong current yesterday at electrician. The feed for the in-line pump bosch 044 was taken from the oem fuel pump and this is where i had lower current. We grounded the earth to the body and this improved but wasn,t happy to put an earth strap permanently for fear of return to trhe ecu.
With the a/c switched off have enough current to feed both fuel pumps so can run without but would like to get to the bottom of this. Alternator charging fine, fitted a new a/c compressor a few months back and not cooling in traffic with low voltage. All seem related to low voltage in the sytem and a relay cutting her out on load but sytem has been fine for 3 years and just renewed the main componnents above. Small 30 amp relay siver in colour underneath relay 109 beneath steering column near the fuel pump relay seems a bit worn for weather but don't know it's function.
Have limited internet access and will check back in a couple of hours mayse one of you guys had a similar problem.
Any help would be appreciated