Fuel Pump failure
Posted: Sun Jan 14, 2024 17:57
Yesterday I had my first Failure to Proceed in 16 years of ownership... 
The car started to lose power on the A465 Heads of the Valleys Road at Pwnt Uchaf - the "Highest Point" - 1350 feet. 30 seconds later I was coasting down a (very opportunely located) slip road. It was rather cold and getting dark so not ideal for a breakdown... After pondering the problem for a minute or two I tried to restart the engine - it ran for a few seconds then died again. So there appeared to be a spark and no major mechanical issues, and we were able to limp into a car park in 3 or 4 attempts. I then noticed I couldn't hear the familar sound of the fuel pump.
Remembering what I had read about SU pumps, I removed the boot trim and protective plate, and gave it a few good hard taps with a socket wrench. Loaded everything back into the boot and turned the key. The pump ran, although the pulsing was very erratic to start with, then followed the normal pattern of slowing to a halt as the float chambers filled. Started the engine, and all appeared to work again. We drove another 20 miles home with no further issues. So it looks like the pump stopped for some reason, and the engine ran out of petrol.
The pump on my car is the electronic AZX1307EN, fitted by the PO in 2003. Never given a moment's trouble until now. Does tapping an electronic SU pump make any difference, or is this only a fix for the old points types, and therefore was it purely coincidental that it started running again after I hit it?
Another possibility I thought about was some debris in the fuel actually jamming the pump - can this happen? I thought there was a gauze filter on the outlet of the tank to prevent this.
Thanks for your thoughts gents, especially anyone with some knowledge of the SU pumps.
The car started to lose power on the A465 Heads of the Valleys Road at Pwnt Uchaf - the "Highest Point" - 1350 feet. 30 seconds later I was coasting down a (very opportunely located) slip road. It was rather cold and getting dark so not ideal for a breakdown... After pondering the problem for a minute or two I tried to restart the engine - it ran for a few seconds then died again. So there appeared to be a spark and no major mechanical issues, and we were able to limp into a car park in 3 or 4 attempts. I then noticed I couldn't hear the familar sound of the fuel pump.Remembering what I had read about SU pumps, I removed the boot trim and protective plate, and gave it a few good hard taps with a socket wrench. Loaded everything back into the boot and turned the key. The pump ran, although the pulsing was very erratic to start with, then followed the normal pattern of slowing to a halt as the float chambers filled. Started the engine, and all appeared to work again. We drove another 20 miles home with no further issues. So it looks like the pump stopped for some reason, and the engine ran out of petrol.
The pump on my car is the electronic AZX1307EN, fitted by the PO in 2003. Never given a moment's trouble until now. Does tapping an electronic SU pump make any difference, or is this only a fix for the old points types, and therefore was it purely coincidental that it started running again after I hit it?
Another possibility I thought about was some debris in the fuel actually jamming the pump - can this happen? I thought there was a gauze filter on the outlet of the tank to prevent this.
Thanks for your thoughts gents, especially anyone with some knowledge of the SU pumps.
