Reached my limit of time anger and busted knuckles with this car. Has I towed to the shop today after the new CMP and CKP did nothing. Im sure ill have an update in a day or so for you all

 

The starter motors on car engines draw current in the range of 300-500 A, more towards the upper figure in the case of our V8's (up to 1,000 A on diesel pick-up truck engines). With this kind of current draw, the battery voltage will (temporarily) drop significantly during cranking. It is, however, possible that the Jag ECU will not allow the engine to fire-up if the battery voltage is below 11.4 volts before attempting the engine cranking as, at this voltage, the battery has just some 15% charge and, whilst it may still crank the engine, its voltage drop during cranking would be so much that it would confuse much of the car's electronics.

 

Been a while since an update. Just so you guys know the car is running again. Andy at Jaguar Doctor here in Orlando got it going. Turns out a wire somehow pulled out of the bottom of the front fusebox and 2 relays (ignition and injectors) were kinda hit or miss working sometime and not others. $230 bucks and we're on the road again. There's a couple issues to clear up (cylinder 5 misfire and that fuel return hose in the tank) but other than that we are 100%. Thanks for all the help

 

Might want to be more careful next time you work around the fuse box . . .

Must feel good to get it going tho . . I am glad this worked out.

 

Likely last question regarding this issue. The car is running and all is well. Gonna replace the corroded section of rubber hose on the return line in the tank mentioned above. It was so bad I didn't need to taken off the clamps, just pulled it and it broke in half. It had a small plastic one way check valve inside it and uses a molded hose to fit the valve in the hose. Seems it allowed fuel to flow from engine to tank but not in the other direction. What issues might I encounter if I left this check valve out for Now? The valve won't fit in the hose I have and I have to search for the molded one.

 

I have not heard before of a check valve in the fuel return line. Normally, it is an unrestricted line through which the excess fuel released by the FPR flows back into the tank. It appears that the check valve is inserted to prevent complete drain back of the fuel from the fuel rails if the car is parked for a long period of time. After the engine shut-down, if the injectors are not leaking and the fuel pump check valve is good, the only way for the fuel to slowly drain back into the tank is through the FPR which, I think, does not seal 100% when not in operation. The check valve in the return line will, in its direction in which it allows flow, hold some very small pressure and this will prevent complete emptying of the fuel rails.

I wouldn't worry about it as it is not really necessary. If you park the car for a month or so, just switch the ignition on and off a few times prior to cranking the engine and the fuel system will be primed well even if the fuel rails were completely empty.

 

I don't know the Jag fuel circuit well at all, but the fuel pressure of 2.5 Bar almost has to be maintained by a back-pressure regulator somewhere between the rail and the tank. That regulator would keep fuel in the rail unless it won't close tight. Is this that valve?? Surely a cheap, crum version, if so

 

I went ahead and fitted a rubber hose without the check valve. Car seems to be fine. It was fitted inside the hose in a direction where it would allow flow from the fpr to tank but not from tank to fpr. Anyway, seems fine without it