Hi,
Since I have owned my XJ6 it never had any problems at all until a few nights ago. On two occasions that night I thought that when I hit the gas pedal the car didn't respond correctly but didn't think much of it. Then later that night the car stalled on me. It started right up but started running badly by not responding to the gas pedal initially, then the car responded to the gas pedal then didn't etc. It also stalled in between and the transmission light came on. I managed to get it to go the 4 miles to my house where it died in my driveway. I tried starting it but it would just crank. The battery was a little low at that point so I charged the battery which is 12.4 volts now. A few days later, today, the car started right up with good rpm but 20 seconds later it stalled and hasn't started since.

Having owned an X300 for a while now I immediately thought that it might be crankshaft position sensor even though my tach was reading 200 while cranking. Since I also own a XJS I swapped the CPS with the XJ6 and the car still does not start. After my car was misbehaving the other night every time I turned the key to restart the car the transmission light would stay on. However, today the light did not come on even once.

What should I be looking at next?

Thank you,
Jomo

 

Codes , but you were more concerned with getting home

The fuel pump can be failing on you , you can jumper the fuel pump relay to directly control and power it

The transmission light may be a clue you have a crankshaft position sensor ,, throttle position sensor ,or a mass air flow meter failing

There are some volt meter test

Are you familiar on how to test the TPS with a volt meter ?

If you put a meter on the swapped CLPS it should read 1300 ohms to be a good swapping match

 

No, I don't know how to test the TPS with a volt meter. Can someone please give me the process?

 

on the middle wire of the TPS it will read 0.60 volts DC at the idle stop

You don't have to have the engine running but the key should be in the run position and the TPS must remain connected

The connector is on the bottom of the throttle body so you can follow the Green / Yellow color wire as it comes over the top of the fuel rail

slowly very slowly rotate the throttle open and the voltage will smoothly increase

If the meter jumps or have no voltage to start with you will have a bad TPS

There should be a lock clip on the connector to keep it connected as mine was missing

to unlock the clip, it is just like the camshaft position sensor as you need to compress your finger tips to release it

The mass air flow sensor will read 1.2 volts DC at the idle stop on the middle Green / Pink wire of it's connector which must remain connected

The engine has to be running

By twisting the throttle butterfly and RPM increasing the MAF voltage will increase toward 5.0 volts DC

Ask questions

 

Parker,
I am confused about how you claim to use the volt meter. You clearly told me that the middle wire of the TPS will read .6v. Of course, you can not read voltage from one wire. I suspect, but want to be sure, that the other 'wire' is ground? That is, I read the voltage between the middle wire of the TPS and ground?

Thanks for your help.

Jomo

 

Yes your black meter lead would lead would be on a ground

of the 3 wires on the TPS one will be 5.0 volts constant reference volts DC

one will be a ground

the middle wire will read the 0.60 volts DC and change with throttle movement

 

I tested the TPS and found it to be fine. I then squirted some starting fluid into the throttle and the car started and ran just fine for about 30 seconds and then died. I tried again with similar results. However the car will not start on its own. So we established that I have a fuel problem. Tomorrow I will investigate this more closely. I guess the 1st thing I should do is bypass the fuel pump relay?

Any suggestion on what to try next will be appreciated.

Thanks,
Jomo

 

Jumper 3 ( power ) to 5 ( pump ) with a heavy gauge wire with blade type connectors on the ends of the wires

Socket 5 will be the forward most socket.

The local auto parts store can make one for you

With the relay jumpered it will drain the battery with your keys in your pocket

There is a second relay that powers the fuel injetors which is the large right # 5 ECU controlled relay which is controlled by the ECU and brings power back into the ECU and places power sitting on the injectors as well as several more engine sensors and valves.

This large relay can be swapped with a headlight and such of the same part # as there are several

The fuel pump relay control comes from fuse # 10 of the right heelboard fuse box in which the small relay in the corner must close , you can swap this relay with the left engine bay fuse box which in reality only runs the car horn

This will be point 7 double hash circle on the last pic

 

When I arrived home today I checked the fuel pump relay and it seemed not to be working so I swapped it with another relay and the car started.

Thanks for all your help.

Jomo