Quick backstory. My jag would crank but not start about a week ago, and after some research I concluded it was the fuel filter. So after replacing that it ran just fine up until today. When I started it, it ran super rough and was idling at roughly 700 rpm, then stopped. Does anyone know what this could be and how I can fix it?

 

If it's running rough..There should be a check engine light.

Do you have a way to pull any fault codes?

If you choose to go to a parts retailer to have the codes read..Do not let them clear them. We will have to start from scratch if they clear the codes.

 

What led you to change the fuel filter? Did you have low pressure at the injector rail? If so, did you check the fuel pressure again after replacing the filter?

If you did (and still do) have low fuel pressure, I'm wondering if the pump itself could be marginal. Maybe the new filter helped just a little, but was masking a problem with the pump.

Another possibility is crud in the tank clogging the filter again, but this is kind of remote as this would probably kill the pump first.

 

yeah, I’d be surprised if anything abnormal was in my fuel tank because I only put premium fuel in it(unless some asshat but anything in there). So I’m going to go w/ my fuel pump causing the problem. Knock on wood that the problem’s fixed after that.

 

Hi Momma's Cornbread

It may not be the fuel pump.

If the engine is missing, it could be a number of things such as, coils, plugs or vaccuum leaks.

If the fuel pump is on the way out it will become difficult to start (like it has no fuel) and often will blow the fuel pump fuse in the trunk.

The fuel pump can be tested at the shraeder valve. This link at post 4 shows the correct fuel pressure in lbs per square inch.

https://www.jaguarforums.com/forum/s...essure-200148/

If the car has done a few miles and it is the original fuel pump, then it might be worth changing, but it may not solve your problem. My fuel pump went at about 180,000km (110,000 miles).

Good luck
Paul

 

thanks for the insight, I’ll check the shraeder valve. But upon some further inspection, the engine lamp and battery lamp are on. What could this signify?

 

If the check engine light is on there will be a code.
If you go to Autozone, O'reillys or one of the others they will check it for you free, get a note of the code and let us know.

 

If the ignition is on but the engine is not running, this is normal. These lights go out when the engine starts if all is good.