Hello

My jag sat for a couple of years. I would start it and let it warm up every now and then and it started fine. Eventually I had to put a new battery. Now it will crank but wont start. I checked fuses and the inertia switch. My obd reader is showing low fuel pressure but I have no active codes. Anything else I can check for I face the fact that my pump may be out?

 

jag1022, first things first. If you have a code saying low fuel pressure, confirm that. Depending on the year of your car (2005 and before should have a shrader valve on the fuel rail for you to test the pressure with), use a gauge to measure the fuel rail pressure. Should be at 55 psig with the engine at rest (power applied to the pump) or 40 psig with the engine running.

Assuming you are getting no pressure, I would next try to start the car, but this time turn the key to the RUN position and hold there for 5 seconds or so. You should hear the fuel pump run at this stage and if it builds up pressure, will turn off at a few seconds. After the 5 second wait, now attempt to start the car. If it starts, your fuel pump is starting to go. If still no luck, keey the key in the RUN position and now go back by the passenger rear tire (since you are in the US) and if you look just in front of the tire, you will see the bottom of the gas tank. If you look closely, there are indentions on it. One of them makes a half moon. Find the center of that half moon and using your fist or other solid object smack the fuel tank on that spot. You may hear the fuel pump suddenly start working again. Again, attempt to start the car using the 5 second wait. if the car starts now, you simply had a fuel pump that stuck and needed a bit of "encouragement". But, this is also telling you that the fuel pump is getting ready to fail. So, this is where you can drive it for awhile, but it is only going ot get worse.

If you still have a no start condition, then let me know and we can walk you through diagnosing your car. I just need to know year of your car. If you have an O4, then I will also need to know the month it was made (written in the driver's door jam).

 

Hello. No codes. I tried the above. Still no start. I found the fuel control module under rear seat. Tried to backprobe the yellow and red to ground to check for voltage when put in the on position. No voltage.

 

Sorry. Its an 03 manual.

 

My assumptions:
1. fuel filter may be blocked: Swap fuel filter.
2. The small moveable inside of the fuel pump may be seized up (due to the petrol gone old and gluey): Swap fuel pump.

 

jag1022, you want to look at the brown wire with a green stripe. That has the main power coming in. It is switchable 12 VDC. So, to have power, you need the ignition in the RUN position. I would also check the black wire to make sure that it has a low resistance to ground. But, if you have a good ground and 12 VDC on the brown/green wire, then the pump should run. If not, then you most likely have a failed fuel pump module since you say you don't have power on the red and yellow wires.