Intermittant fuel pump circuit feed

[paul jacobs]

I seem to have a problem with an intermittant electrical feed to the fuel pump on my 21.

 

Symptons are that it can be running perfectly, I turn the engine off for a short while, say 5 or 10 minutes, then when I turn the ignition back on to start the engine, the pump doesn't work, if I then leave it for some while again, say between 5 - 30 minutes or longer, the pump may well work again, or not.

 

If I remove the fuel pump fuse [which is OK] and take a feed, using a short length of wire, from anothe circuit on the fuse board, it will work perfectly.

 

My first thought was that the wires behind the fuse board were not making a good contact, but I've wiggled them all around with no discernable effect, then I thought the fuse holder may be slightly corroded as some water may have run over the fuses when washing the engine compartment down, so cleaned these - same result.

 

I'm now wondering if the after market immobilizer that I had fitted about 4 years ago, is causing problems on only that one circuit. I phoned the immobilizer fitter yesterday, who thought that it would be most unlikely that this would be the fault, he reckons that they are very reliable anyway, being solid state, and wouldn't give problems on only one circuit, but then he would say that wouldn't he. [Me, cynical, surely not!] Note that this immobilizer is NOT the standard Rover one, but an aftermarket fit one.

 

Right over to you guys, can anyone come up with the definitive answer before I leave for Stoneleigh on Sunday a.m.?

 

 

[julians]

I had a similar problem with my fuel pump, it turned out to be the earth from the fuel pump was attached to a bit of corroded chassis, reattached it to a nice clean bit and it works fine.

 

Maybe not your problem if you say running a new live wire to it fixes it, but worth a look into anyway.

[ECR]

Paul

 

I had similar on my VX. It turned out to be the feed wire shorting out on the chassis where it exited the rear of the transmission tunnel.

 

Worth a look if your wire routing is the same

[paul jacobs]

Thanks Roger and Julians, I will check the feed and earthing side of things, but somehow feel that there could be something else at the bottom of it.

 

If anyone else has any suggestions, I'd be grateful. Will be at Stoneleigh both days, so if anyone is good with wiring, you're welcome to come and poke around. Just look for a red 21 with a big "For Sale" sign on it....