Fuel Pump failure

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barker_001
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Fuel Pump failure

Post by barker_001 »

Yesterday I had my first Failure to Proceed in 16 years of ownership... :shock: 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.
Bryan

1990 Excel SE

"Look, there's a Ferrari..."

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rbgosling
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Re: Fuel Pump failure

Post by rbgosling »

Hitting the pump I believe is a particular cure for the original points pump. I used to do it regularly with my MGB GT, where the pump is in a far more exposed position under the car near the O/S rear wheelarch! But that doesn't necessarily mean that there isn't a moving part that responded to "persuasion" with the electronic points replacement - I've not seen how they work, but there must still be something physically moving.

After my pump points melted, I replaced the whole pump with a cheap imitation Facet pump I found on eBay. Slight PITA tracking down some thread adaptors to make it fit, but it's been faultless for 5 1/2 years so far.
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

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Dwaynem884
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Re: Fuel Pump failure

Post by Dwaynem884 »

I have an AZX 1308 EN that gave up the ghost recently. Unsure as to when it was last replaced. It was poorly mounted by a p.o. . Took it apart and everything seemed to look ok mechanically, but with power to it, all it would do it make the circuit but not break it, therefore the diaphragm would not oscillate. Having no electrical experience, I bit the bullet & got a new one through LotusBits. They are the same price as going to SU Direct. I have the new one fitted and it's operating well so far. One point to note, the clamping bracket in the boot has 3 bolts, one to tighten the clamp around the pump, and two to mount the bracket to the body, one external (front) & one internal (rear). The rear internal is not a captive bolt. Mine, now unfortunately resides within some dark recess with the bowels of the car. If you can remove the pump without loosening the rear mounting bolt & nut, it would save similar heartache.
Dwayne
1980 Ford Fiesta 1.1 Ghia
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barker_001
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Re: Fuel Pump failure

Post by barker_001 »

Thank you Richard and Dwayne. Did either of you find any debris or fuel gum inside your old pumps?
Bryan

1990 Excel SE

"Look, there's a Ferrari..."

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rbgosling
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Re: Fuel Pump failure

Post by rbgosling »

barker_001 wrote:
Thu Jan 18, 2024 09:05
Thank you Richard and Dwayne. Did either of you find any debris or fuel gum inside your old pumps?
My pump kinda caught fire. It was a horrible melty mess inside. I wasn't really looking for debris...
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

Pete Boole
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Re: Fuel Pump failure

Post by Pete Boole »

rbgosling wrote:
Thu Jan 18, 2024 09:31
My pump kinda caught fire
:shock: :shock:

Pete

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rbgosling
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Re: Fuel Pump failure

Post by rbgosling »

Pete Boole wrote:
Thu Jan 18, 2024 11:08
rbgosling wrote:
Thu Jan 18, 2024 09:31
My pump kinda caught fire
:shock: :shock:

Pete
Fortunately only the electrical points bit of it, no fuel ignited. But it wasn't a good moment. I still managed to bodge in a replacement pump by the roadside, and complete the journey!
"Farmer" Richard

1990 Lotus Excel SE (Lilith)
2022 MG MG5 EV (not due to be a classic for quite a few years...)
2011 Nissan Leaf (Ragly - EV pioneer, must be due to be a classic one day)

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barker_001
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Re: Fuel Pump failure

Post by barker_001 »

rbgosling wrote:
Thu Jan 18, 2024 09:31
My pump kinda caught fire
Hmm yes, debris probably not at the top of your list on that day... :?
Bryan

1990 Excel SE

"Look, there's a Ferrari..."

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