Fuel pump fuse keeps blowing - why?
Discussion
Hi,
So, got up in a great mood today, we were off to the Hampshire TVR club Christmas dinner! The car was clean and waxed and ready to go. It started up but did sound like it wasn't running on all cylinders for a couple of seconds. Then it ran fine, although the fuel pump pitch kept changing, suggesting the pump was running faster and slower.
Then, 4 miles down the road, sat at idle, it spluttered and stalled. It was completely dead and wouldn't turn over. I pressed the immobiliser button a few times, nothing, plugged in the fob a couple of times and eventually it did turn over, but wouldn't start. Then I couldn't get it to turn over again.
I checked the fuses and the fuel pump fuse had blown. I swapped it for another 20A fuse and it popped again, so left it by the side of the road and got a taxi home. Then drove to the dinner in our reliable Honda!
On the upside, I had a nice meal at the Milburys and enjoyed chatting to everyone.
Hope to hear of some solutions. I plan to have a look at it tomorrow night.
Dan
So, got up in a great mood today, we were off to the Hampshire TVR club Christmas dinner! The car was clean and waxed and ready to go. It started up but did sound like it wasn't running on all cylinders for a couple of seconds. Then it ran fine, although the fuel pump pitch kept changing, suggesting the pump was running faster and slower.
Then, 4 miles down the road, sat at idle, it spluttered and stalled. It was completely dead and wouldn't turn over. I pressed the immobiliser button a few times, nothing, plugged in the fob a couple of times and eventually it did turn over, but wouldn't start. Then I couldn't get it to turn over again.
I checked the fuses and the fuel pump fuse had blown. I swapped it for another 20A fuse and it popped again, so left it by the side of the road and got a taxi home. Then drove to the dinner in our reliable Honda!
On the upside, I had a nice meal at the Milburys and enjoyed chatting to everyone.
Hope to hear of some solutions. I plan to have a look at it tomorrow night.
Dan
If the fuel pump fuse blows immediately the it shouldn't be too hard to diagnose. I would start by removing the power wire off the fuel pump. (If not sure which is power remove both) replace fuse again and see if it blows. If not the your pump has gone to earth ( bad). If it still blows then the wire between fuse and pump is going to earth. (not so easy o trace). Good luck. my money would be on a bad pump, seen it a few times.
zed4 said:
LongBaz383BHP said:
Check out my thread ' Its broken'
Thanks, I'll have a look at that wire tomorrow. Ps. Southways have made a very tidy job of routing and securing all the wires under there when they did the cam. Looks much better.
That doesn't mean anything if your tank has anything spurious in it.
An early issue I had with mine was the engine trying to die on me intermittently. It already had new pump and filter so the tank was removed and drained - there was an "unknown substance" in the bottom of it that had blocked the filter. The tank was cleaned out, filter and pipes replaced and all was well (with fuelling at least!)
An early issue I had with mine was the engine trying to die on me intermittently. It already had new pump and filter so the tank was removed and drained - there was an "unknown substance" in the bottom of it that had blocked the filter. The tank was cleaned out, filter and pipes replaced and all was well (with fuelling at least!)
keith2.2 said:
That doesn't mean anything if your tank has anything spurious in it.
An early issue I had with mine was the engine trying to die on me intermittently. It already had new pump and filter so the tank was removed and drained - there was an "unknown substance" in the bottom of it that had blocked the filter. The tank was cleaned out, filter and pipes replaced and all was well (with fuelling at least!)
Fair point. I will bear that in mind. An early issue I had with mine was the engine trying to die on me intermittently. It already had new pump and filter so the tank was removed and drained - there was an "unknown substance" in the bottom of it that had blocked the filter. The tank was cleaned out, filter and pipes replaced and all was well (with fuelling at least!)
NZ fan said:
If the fuel pump fuse blows immediately the it shouldn't be too hard to diagnose. I would start by removing the power wire off the fuel pump. (If not sure which is power remove both) replace fuse again and see if it blows. If not the your pump has gone to earth ( bad). If it still blows then the wire between fuse and pump is going to earth. (not so easy o trace). Good luck. my money would be on a bad pump, seen it a few times.
Right , disconnected the fuel pump, switched on the ignition and the fuse pops straight away. So that rules out the pump, wiring problem somewhere then. 
zed4 said:
Can someone tell me which relay is for the fuel pump please? The blue connector or the brown one?
I've tested them both, one tests for continuity to earth on two connectors, the other tests one three.
Just had the same problem on saturday. Key in, turn on the ignition and no fuel pump priming.I've tested them both, one tests for continuity to earth on two connectors, the other tests one three.
I had a spare bosch relay, and on my car changing the relay on the blue connector did the trick, and now the fuel pump works a treat.
Now need to purchase another "brown" relay as a spare.
Where did you purchase yours from?
Best thing you can do is buy a multimeter and learn how to use it.
http://www.youtube.com/watch?v=bF3OyQ3HwfU
You can fix most TVR troubles with a multimeter, a length of auto wire, a handful of cable ties & few self tappers
Two years ago my Chimaera stumbled to a halt in the middle of nowhere with exactly the same fuel pump fuse blowing fault.
A quick test with the multimeter revealed a short on the live feed four inches from the pump itself.
I remade this section and after replacing the fuse it burst into life immediately, its also been 100% reliable ever since.
With a TVR you should always carry fuses, a multimeter, a good torch or LED inspection lamp, some twin core trailer wire, a crimping tool, some crimp connectors and insulating tape.
It sounds like a lot of stuff to carry but you'll easily get all that lot & a stack load more tools in a small tool pouch.
Even touring Europe I carry all my emergency tools in a Plano 545TX Tool Bumbag which takes up very little space.
http://www.ebay.co.uk/itm/Plano-545TX-Tool-Bumbag-...
While we're on breakdown essentials, third only to a mobile phone & credit card is the inspection lamp...if you cant see it you cant fix it
http://www.youtube.com/watch?v=bF3OyQ3HwfU
You can fix most TVR troubles with a multimeter, a length of auto wire, a handful of cable ties & few self tappers
Two years ago my Chimaera stumbled to a halt in the middle of nowhere with exactly the same fuel pump fuse blowing fault.
A quick test with the multimeter revealed a short on the live feed four inches from the pump itself.
I remade this section and after replacing the fuse it burst into life immediately, its also been 100% reliable ever since.
With a TVR you should always carry fuses, a multimeter, a good torch or LED inspection lamp, some twin core trailer wire, a crimping tool, some crimp connectors and insulating tape.
It sounds like a lot of stuff to carry but you'll easily get all that lot & a stack load more tools in a small tool pouch.
Even touring Europe I carry all my emergency tools in a Plano 545TX Tool Bumbag which takes up very little space.
http://www.ebay.co.uk/itm/Plano-545TX-Tool-Bumbag-...
While we're on breakdown essentials, third only to a mobile phone & credit card is the inspection lamp...if you cant see it you cant fix it
Calling it a day now, too tired to try and get my head around the multimeter readings!
Also, I've traced the fuel pump yellow wire back from the fuel pump to the connector behind the carpet, by the passenger's seatbelt, and it's got continuity from the pump to the connector there. But it's not buzzing back to any of the pins on either of the two relays! Also, I've checked for any shorts on any of the other pins on the connector and there aren't any. I've also checked the live feed to the pump (at the pump connector) against the ground and there's no continuity, so I can't see where there's a short.
Still more investigation to do then.
Also, I've traced the fuel pump yellow wire back from the fuel pump to the connector behind the carpet, by the passenger's seatbelt, and it's got continuity from the pump to the connector there. But it's not buzzing back to any of the pins on either of the two relays! Also, I've checked for any shorts on any of the other pins on the connector and there aren't any. I've also checked the live feed to the pump (at the pump connector) against the ground and there's no continuity, so I can't see where there's a short.
Still more investigation to do then.
Edited by zed4 on Tuesday 10th December 00:04
If anyone else has any more info or help for me, discussion has moved more towards this thread now: http://www.pistonheads.com/gassing/topic.asp?h=0&a...
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