Hey everyone,

This thread is kind of an attachment to another one I have. Sorry for the repeat but I really need some help. I am still having a lot of trouble getting the fuel pump to run on my 84. I am stuck! Anyway, the pump is new and the relays are new. I had one diagnosis being the ground circuit for the relays in the ECU being bad. The only problem is, I have no idea how to fix this. Does anyone know how to fix this? Does anyone else think there maybe something else that might be wrong?

Any help would be great! Thank in advance!
Keith

 

AJ6 Engineering in Britain repairs the ECUs. They're on the www. There might be others, I'm not sure.

It would be easy to rewire the circuit so the pump runs whenever the key is on. Others have done so. There is a safety aspect involved, though. If there was an accident or fire fuel would keep pumping even if the engine isn't running

Cheers
DD

 

Hi guys, Doug, not tried this on a Jag but in my old V8 Off Road Landies and Rangies I used to fit a prominent battery cutout switch to kill the electrics in the event of a compromising situation.

This by default also killed the fuel pump.

 

The Jags do have an inertia switch for that purpose but I'm not sure what the triggering parameters are. We'd have to crash the car to find out :-)

I wouldn't wring my hands with worry or have any sleepless nights because of it, but I can think of several scenarios where you wouldn't want the fuel pump to run with key on, engine off.

Cheers
DD

 

I'll try to dig out the pics of my old spares car. It was rolled approx 5 times with 4 adults onboard.

Not only did the inertia switch not go off, but the air bags also did not fire!

No injuries to anyone BTW, but the car, flat would be an understatement.

I agree, about not to worry too much, but if you hard wire the fuel pump then at least add an on/off switch somewhere.

Jfrog, you refer to this being a continuation of a previous thread, to avoid going around in circles, with try XYZ, when you have already tried XYZ, please will you post a link to your previous thread here.

Cheers,

 

Great! Thanks guys! So, how would I go about re-wiring the fuel pump? Would it be cheaper to do this compared to having my ECU repaired?

Sorry about that Translator, here is the link to my other thread: https://www.jaguarforums.com/forum/s...ad.php?t=28084

Thanks again guys!
Keith

 

As I recall....others will chime in....it's simply a matter of taking the orange wire at the f/pump relay and attaching it to a permanent ground

Cheers
DD

 

So, I see that the orange wire is feeding into one of the relays. Where exactly is the orange wire coming from? Do I just cut the orange wire at the bottom of the relay and ground it out in the trunk?

Thanks,
Keith

 

It comes from the ECU, which send a ground signal to energize the relay. Yes, just clip the orange wire and run it to a good ground

Cheers
DD

 

I went ahead and clipped the orange wire from the relay and ran it to a good ground. I still have no power to the fuel pump. Any other suggestions??

Thanks,
Keith