C70 Convertible Fuel Pump Replacement
 

Hi,

Many apologies for the length of this!

I have a 2005 T5 C70 Convertible (115,000 miles) that is fantastic except for the occasional non-starting problem. This first occurred last summer, drove to supermarket and it wouldn’t restart (I put it down to the heat - car is in South west France) eventually it restarted.

A week later it wouldn’t start at all, so phoned the mobile mechanic and when he arrived...it started! He said it was more likely the relay so, I bought both the relay and fuel pump because I wanted both changed. He fitted the relay but couldn’t get to the fuel pump because of limited access and said that the fuel tank needs to be dropped to change the pump. However, in his opinion the fuel pump was OK because it either works or it doesn’t.

So yesterday, after 1000 miles - (same supermarket) the car wouldn’t re-start, turn engine over, it fires up then cuts out, waited 15minutes and all was well!!

Question - Fuel pump change and is dropping the tank the only way to fit the pump?

Thanks Steve

yes as there is no access hole in the floor of the car ... empty the tank first though it makes the job much easier !

Before you disturb the the fuel tank try cleaning the connection of the immobiliser antenna ring (located around the ignition switch) with some contact cleaner.

i'm assuming it is the new steel roof C70 ?? we need to confirm that first of course . that was just around in 2005

Hi, it’s the Mk1, just the rag-top

Hi BlueStag

As Baffler says, you shouldn't just assume that it is the pump.

If the pump buzzes for a few seconds when you turn the ignition on (you may have to get someone to listen under the boot), then the pump and relay may be fine. It turns itself off when the necessary pressure is reached.

If the car runs fine when it has started, that would also tend to indicate that the pump can keep up with demand, (and that the relay is fine).

If the immobiliser system is not satisfied that a correct key is in the ignition, the pump will run etc as normal, but the engine will be shut off after just a second or two. ie the engine will fire up as normal but then quickly shut off.
The chip in the key is detected by an antenna ring (which sits around where the key goes into the steering lock). If you have a second key you should try that to see if that helps, but the antenna ring is more likely.

I think a code reader would tell a mechanic what is going on.

HTH
Steve

pretty easy to lift out in the boot, towards the right hand side not far from the rear seat backrest .

Update on solving starting issues.

Camshaft sensor was faulty, car is now running (and starting) like a dream.

Also changed the fuel pump and crankshaft sensor to prevent any other issues.

Just have to sort the roof electrics which leaves 15mm gap when it retracts.