I have a check engine light on my 1998 Jaguar xk8. Fuel pump is locked out. fuse is good, relay is good, fuel pump is good. The ECM just has pump locked out. How do I clear the check engine light. No codes show up with a scanner I disconnected the battery and drained off the power still has the light. Where do I go from here???

 

Hi,
I woud try another scanner. I'd expect codes if the check engine light is lit.

'Fuel pump is locked out'? Do you mean it's not running, hence no fuel pressure and the car will crank but won't start?

 

I have been trying to find someone with a different scanner but no luck so far. I can jump around the relay and make the pump run so it is good and so is the relay but it will not energize as it should.

 

Bear in mind that the fuel pump only runs for 2 seconds or so when you first turn the key, until the engine starts.

So the motor will crank but not fire?

 

Yes the motor does cranks. It just appears to me that the check engine light is causing the problem. The car was working fine when I parked it. I had a small coolant leak around the thermostat housing so i decided to check the bolts to make sure they were tight. I had to unplug a sensor that is near the housing (two wires). The sensor itself is under the intake but the connector is next to the housing. I am assuming that is what caused the check engine light but I can't get the light out now. I have tried the code reader no codes so I disconnected the battery for about 30 min with a jumper wire connected from negative to positive leads to drain off all voltage still no progress. Thanks for the reply all advice is appreciated .

 

Yes, there is a connector on each side of the thermostat housing - one for each knock sensor. The CEL may be as a result of a problem with one of the sensors, but that shouldn't stop the car starting. You've done the hard reset so that's out of the way.

Member Gus has put a no-start checklist on his website that may give you some ideas:
JagRepair.com - Jaguar Repair Information Resource

Is the battery up to scratch? You should see around 12.5V across the terminals with the ignition off.

Check fuel pressure at the Schrader valve on the front LHS of the engine. Turn the ignition on briefy and then off again. Unscrew the plastic cap (it's blue on mine) and depress the centre pin. You shoud get a good spurt of fuel when you do this, but have a rag handy to catch any spray and watch your eyes...

See this thread from Johnken showing its location:
https://www.jaguarforums.com/forum/x...0/#post2204863

Check for spark (see Gus' guide).

Finally, did you run the engine very briefly from cold then stop it again, and/or does it appear to crank more quickly than usual?