Hello I have a 1998 XJ8 that ran fine one evening and next morning would not start. I have had a very rare problem where the engine dies randomly while driving but it happened so rarely I couldn't pinpoint it.
I have checked fuel pressure(40psi), spark, replaced camshaft sensors and crankshaft sensor. Camshafts are turning. When I pulled plugs to check spark they were saturated in fuel. If i disconnect fuel pump and hold throttle wide open while turning it over it acts as if it will start but as if timing is also off. I can put a tiny bit of starter fluid in it and it will turn over but backfire on some tries.
Only codes are 1000 and 1336 Crankshaft/Camshaft Sensor Range/Performance.
I know the camshaft and crankshaft sensors work because i swapped them with a running 1998 xk8 with the same part numbers, tried them on the XJ8 and put the parts from the xj8 on the xk8 - xk still runs fine.
Any Ideas would be welcome
And thank you in advance

 

Do some research on cylinder wash. If it ran last night, but only for a short period, that may be your problem. Sounds like there may be other issues too.

 

Check the forum for "her majesty won't start." That might give you some ideas.
search "won't start" and "cylinder wash".
I guess there is a problem with having almost zero compression. Adding a small amount of oil will allow you to have compression so it will start. I don't have any
personal experience with this though. I did have an issue with random cutting off
when accellerating hard and then as soon as I backed off the throttle the engine
stalled. Cleaning the Throttle body fixed that for me.

 

I don't think it's a wash issue. We drove it for about an hour the night before. Before I replaced the sensors I disconnected the battery for a day to hopefully reset any issues with the CPU.

 

Oops, posted reply without looking at what was typed (A hazard of not having typing skills) Last part of message didn't get typed. I will push some oil in the cylinders and see what happens. I know I'm getting ahead of myself but if it is cylinder wash how do you prevent it? I didn't see anything on the other threads about why it happens just what to do if it does.
Thanks

 

When you start from cold the fuel mixture is rich, and if shut off too soon there is enough fuel in the cylinders to wash the oil off the walls as it leaks past the rings. You do not have to run to full operating temp to avoid the problem, but that is a good idea, as it also helps prevent condensation of moisture in the valve covers and crankcase.