Fuel Pump Relay Earth Fault

[kjopen]

Can anyone tell me how to resolve this fault please i.e. do I now have to take the car to an auto electrician or has someone or can someone tell me what I need to do?

Do I split the fuses/relay box apart to reveal the internals and either solder the bad earth, do I replace the whole unit with a new or ebay purchased replacement?

The fault condition is:- occasionaly, the car refuses to start, it will turn over fine but not start. The fuel pump does not run. (the car does not hesitate or cut out when it does run though). Checking the fuel pump relay, the 12v from the ignition arrives at the relay coil but the relay does not energise, if you open the relay and manualy close the contacts then the fuel pump will then run ok - but the car will still not start.

Measuring the otherside of the relay coil point on the relay housing, it is not sat at 0v (earth) like I would expect hence, the coil does not energise as it should.

My understanding is that this means an earth fault.

Can anyone help please?

[Cragus]

Could be a bad relay earth m8 as they are common. Take it to garage or look at it yourslef and check if the connection is ok as if there is intermittent function of the relay it could mean arcing has occured which in turn could mess the fusebox connection up. This happened on mine and i had to replace the fusebox and have it re-wired costing me £80 at my local garage. The earth can be bypassed but is only a temporary solution. Hope this helps.

[kjopen]

Thank you. Will post updates for other readers here.

[pimpmaster]

hi ive had similar problems with my 2.oL 16v in the end it was the coil afterall, sounds silly but if you have mate with the same car perhaps he might allow you to swap coils for 20 mins (not too hard to change) hope this helps good luck!

[kjopen]

Thanks for the tip and I'll give it a go should the following not prove true...

Due to all the information I gathered I thought this has got to be the fuse box so, I carefully pulled the fusebox down as far as I could, then having looked at the box I could see that it is made of two parts with clips to help open it......, I popped a few of the clips to try an take a peak to see what damage I could do if I proceeded etc., I could see what are probably 'rails' inside and thought one of those must be loose or a bad connection however. I was reluctant to end up with a none working vehicle so stopped.

I decided I would buy a second hand one and either strip that or take the chance and remove the existing one and replace it. So, I have ordered one from ebay - what the hell.

Here's the thing, ever since I did the above the car has been PERFECT! Hence, I'm pretty sure the fusebox is the issue and me disturbing it has sorted it - I know this could be temporary though.

Will keep posting on progress

[kjopen]

.....spoke too soon, car wouldn't start this morning first thing. But then 4 hours later started straight away without hesitation! So, waiting for my fusebox to arrive!

[kjopen]

Car still faulty and driving me nuts!

At the moment it wont start at all, to recap; turns over fine, no spark, fuel pump not running. I can make the fuel pump run by manually closing the fuel pump relay contacts - or supplying an earth to the fuel pump relay coil.

My brand new fuse box finally arrived, fitted it (thinking I had a fuse box/fuel pump relay fault) - car still wont start.

Fitted a second hand ECU that was supposed to be good - car still wont start.

I've tried; new fuel pump relay, new ignition switch, wriggling the ignition switch socket, cleaned coil earth strap, cleaned engine block earth straps, checked resistance of coil secondary and primary, new ignition leads, new dizzy cap, new rotor arm, removed and cleaned Crank position sensor, checked I get a pulse from hall effect sensor.

These were the original error messages I had and cleared them however, where the car is I cannot reconnect my laptop up to it to rescan:-

16706 P0322 Ign./Distributor Eng.Speed Inp.Circ No Signal
17645 P1237 Cyl.1-Fuel Inj.Circ. Open Circ.
16684 P0300 Random/Multiple Cylinder Misfire Detected
16685 P0301 Cyl.1 Misfire Detected

Does anyone have any ides that could help me please? Many thanks!

[kjopen]

Given up. Car taken to VW today.

[kjopen]

For anyone interested, the problem was an intermitant fault on the ignition switch and a hard fault on the CPS. If anyone wants to buy a brand new fusebox from me - let me know - I'm in Canada though so you would have to consider the postage cost. Thanks to the two people who made postings trying to help me.