I am Don Ellington in mountains of North Carolina with a 1994 XJS V12 6L convertible with 65,000 miles.
I have had her since 8,000 miles in 1995 and given her great care and garage.
Check engine code FF77 came up
Mechanic replaced crank shaft position sensor #CSS961
Check engine light is out now but she only starts when cold......she will run as long as you want but if you cut her off once warmed up she will not start until you wait a long time to cool down and then she starts.
Since then we replaced both fuel pumps,strainers, and filter
Now mechanic says find a fuel pump module.....maybe that's it.
I can t find one and pray my problem could be something else.
Is it a coincidence that replacing the crank position sensor and the starting problem when warm happened at same time.
Or .....what could be causing this
I am desperate to save my baby from the junk or dismantle yard
Please help
Thanks
Don Ellington
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Welcome to the forum Don,

I've copied this post from your Intro to XJS forum. Members here with the same model will be able to help.

Graham

 

Hi Don

Sngbarratt.com

Looks like they have got one, so best to make sure its what you need as it looks quite an expensive piece of kit

 

If it all started with the sensor replacement, I'd be inclined to think it's a bad sensor that goes open circuit when hot.

 

Arn't there 2 sensors on this engine? Front and rear. Both mine failed within two months of each other. Similar symptoms.

 

You might check air gap on that new sensor and it's also possible other sensors (air temp and water temp) were disturbed when the work was carried out.

 

Good advice on all counts.
What is the air gap on the crank position sensor?
Are there two...one front and one rear?
Can they be installed incorrectly?

Thanks for help
Don