Tank draining, pump and non-starting questions
Posted: Fri Sep 17, 2021 12:43 pm
Hi All,
I have a South African BMW E12 518i automatic that has been sitting in my garage unused for a few years.
It had not been in the family long when it was parked, having developed (if I recall correctly) hot starting issues.
I now want to get it back on the road and would welcome any advice.
Here’s what I have done so far and my thoughts and queries...
First off, I charged the battery.
The engine turned over pretty well but would not start; not a splutter.
I pulled off a plug lead and held it to ground and noted a blue spark when the engine swung.
I suspect fuel issues.
Would like to drain the tank of all old (two or three-year-old plus) petrol, so I disconnected the outlet hose from the pump. But when the key was turned the pump did not respond.It had ceased making the clicking noise it had done earlier during testing.
Tested wires to pump with a multimeter – no voltage.
Tested pump on bench (very briefly) with an independent power supply. It runs.
I read somewhere (perhaps on this site) that there is a (combo?) relay that powers the pump and other vehicle functions but I'm not sure which relay it is. Please see attached pictures. Hoping some can tell me which it is and what they all do.
Also, I have read that there is a switch in the air flow meter/sensor (not sure about terminology here) that triggers the pump relay and that this may have some bearing. I am fairly ignorant about fuel injection but did watch a few Youtube videos on the K Jetronic system (am assuming this is the system in use) so have only a very rough idea of the broad principles.
Should also mention that a second filter (does not look original) had been plumbed into the system after the pump and it was full of debris. Removed and replaced it with a new filter of a similar size by a reputable brand.
Any pointers on what I should do next?
Kind regards,
Matthew
I have a South African BMW E12 518i automatic that has been sitting in my garage unused for a few years.
It had not been in the family long when it was parked, having developed (if I recall correctly) hot starting issues.
I now want to get it back on the road and would welcome any advice.
Here’s what I have done so far and my thoughts and queries...
First off, I charged the battery.
The engine turned over pretty well but would not start; not a splutter.
I pulled off a plug lead and held it to ground and noted a blue spark when the engine swung.
I suspect fuel issues.
Would like to drain the tank of all old (two or three-year-old plus) petrol, so I disconnected the outlet hose from the pump. But when the key was turned the pump did not respond.It had ceased making the clicking noise it had done earlier during testing.
Tested wires to pump with a multimeter – no voltage.
Tested pump on bench (very briefly) with an independent power supply. It runs.
I read somewhere (perhaps on this site) that there is a (combo?) relay that powers the pump and other vehicle functions but I'm not sure which relay it is. Please see attached pictures. Hoping some can tell me which it is and what they all do.
Also, I have read that there is a switch in the air flow meter/sensor (not sure about terminology here) that triggers the pump relay and that this may have some bearing. I am fairly ignorant about fuel injection but did watch a few Youtube videos on the K Jetronic system (am assuming this is the system in use) so have only a very rough idea of the broad principles.
Should also mention that a second filter (does not look original) had been plumbed into the system after the pump and it was full of debris. Removed and replaced it with a new filter of a similar size by a reputable brand.
Any pointers on what I should do next?
Kind regards,
Matthew