How's it going everybody? Been quite a while since I've last been on here and figured I'd share some updates on my project XJS. I bought the car in November of last year and it didn't run at all.

After waiting out winter I decided to try to make some progress on it. Today I went and bought a battery for it to actually see what may or may not be wrong with it. To my much great surprise, it started up after about ten minutes of turning the key on and off. It idled pretty rough there for a little while and eventually smoothed out. Non of the dash gauges for fuel, temp, battery, etc seem to work but I decided to see if it would move. I drove it down my road and everything was good until I tried to come back up. It seems to idle fine but when you give it gas it barely tries to move and just gives a brief moment of power to the wheels. It basically just spins the wheels for like half a second then looses power. I noticed that there was a pretty loud hum coming from the trunk when it was sitting there idling which I guess is the fuel pump? Would like some words of wisdom as to diagnose why it wont really rev up while sitting still or driving. I did manage to get it to rev up to about 3k not long after it was first started and it seemed fine but not sure. Thanks.

P.S I'm not sure if it's possible to upload videos on here but if it is I'll gladly post one up, sure it would help a lot.

 

The hum is indeed the pump trying to overcome all the crud that is in the fuel system. Fuel starvation may well be the reason it will not rev. It would be best to take the boot hoses off, remove the fuel sender and look in the tank to see if it is full of crud, change the filter behind the spare wheel, clean the sump tank under the battery, change the filter in that tank, blow out the fuel lines to and from the motor, change the plugs and try again!
Greg

 

Thanks a bunch for the info. I will try to work on that the next weekend that isn't raining. I was tickled to death when it started. Can you send me a link or a photo that show's where the fuel system first meets the engine under the hood(bonnet)? Also I noticed what looked like transmission fluid in the passenger side throttle body, kind of a redish liquid, not much but it was there. Any ideas?

 

It is sucking ATF up from the gearbox through the modulator vac tube, as the diaphragm in the modulator has failed. New modulator, easy fix, part is not expensive.


The fuel supply line is fixed to the fuel rail on the US passenger side just before the fuel pressure regulator. towards the front of the inlet manifold. The line comes up into the engine bay at the firewall and along the inner wing sort of under the air cleaner box.