Hi,
My 4.0 car has been sitting for about 6 month. Yesterday I replaced the battery with a new one, charged it to be sure it was ready to work but the car doesn't start. It cranks well just doesn't start. I put some starting fluid into the air intake and the car didn't start. This leads to me think that there is an ignition problem. A few years ago this same thing happened (after the car sat for a bit) and it turned out to be a bad cps. How does this part go bad just by sitting in a car? Do you think that it might be the cps again?
Jomo

 

Any of those sensors, or whatever people call them, are basically a magnet, and magnets go "flat" coz they get old.

AJ16 I am assuming here ?

The small loom connector for that sensor, on the timing cover, is notorious for getting gunked up internally. Part it, Lemon Juice clean it, rinse with Solvent, reconnect, try, that bit if free.

Apart from that, my AJ16's were super reliable, so issues were a no event.

 

Orangeblossom is the King on the no-start six cylinder models. I am sure he will be along soon. Something to do with the blue relays going home, I seem to remember.

 

What's going on Greg!

I was just Cooking Lunch!

Hi Jomo

Crank Sensor as mentioned by 'Grant' ( I've had 3 in One Year!) many with AJ16's keep a Spare one in the Glove Box (Amazon are the Cheapest by a Mile!) and they are what I use (The last one was and its still going strong)

Water Temperature Sensor (Try the Paper Clip Trick)

Blue Relays above the Fuses (Passenger Side Knee Panel) they sometimes don't fit properly in their Sockets and need jiggling about as well as a Clean

Fuel Pump Relay underneath the Fender in the Boot Trunk (its the Silver One) but you will need a Mirror on a Stick to find it, unless you can stand on your Head

Water got into the Spark Plug Coil Tube

If it's Fuel come back its another long list

Almost every trick in the Book to Start my 4.0L AJ16 Engine 'Carmen Won't Start!'

 

I removed the CPS from my xjs and put it in my xj6. As strange as it sounds I hoped that my xj6 would not start--and it didn't. I then proceeded to put the cps from my xj6 into the xjs and it started right up.
This is the 2nd time this has happened after the car sat for a few month. Does anything think that I should remove this sensor before storing it? How does leaving a car cause this part to go bad. Very strange to me.
Now by xjs is back on the road. She (oh yeah, since it has a cigar lighter it is a he) drives better year after year!
Thanks for everyones support!
Jomo

 

Update. The XJS is still starting up after I replaced the crankshaft position sensor with the one from my xj6.
The problem is that the car is misfiring (cylinder 5 and 6) and I get a code for a bad crankshaft position sensor.
I put the sensor back in my xj6 and it works fine.
What do you think is going on?
Thanks,
Jomo

 

Crankshaft Position Sensor wires are shielded... is there any chance that something has happened with the shielding on those wires? I'm throwing that out there.

Other than that, I would check for oil in the spark plug wells. I would also pull out each spark plug and check them out. Lastly, I would inspect the wiring at the coil packs. Are they brittle and flakey?

CPS is a cheap part, where aftermarkets seem to do the job just fine. Maybe the magnet is good enough for the x300 ECU, but not enough for the XJS ECU?

 

Thanks for your reply. I will have two new CPS units arrive on Friday. And yes, the shielding has seen better days. So hopefully a new cps will fix everything.

 

+1 for check the plugs and the plug wells.

Paul

 

Shielding is on wires from the harness back to the ECU....it's not on the CPS.

 

You folks are amazing. I installed a new crankshaft sensor and saw no improvement. I check the spark plug wells and well number 6 had a little oil in it so i removed as much as i could. Then i pulled out the plug and it was a little wet with oil. I dried off the plug, put back the plug etc and then went for a drive. The car drive perfectly. On the way home from my drive I stopped by my auto parts store and ordered 6 new spark plug tube sealers along with a new gasket which will arrive tomorrow. Guess what I'll be doing to my xjs tomorrow?
Jomo

 

probably not much.

You still need 13 (?check my math) bolt gaskets. NBC2575CA

Make sure you have a little bit of RTV for the half moons.

I literally just completed this work yesterday….

If you’re using aftermarket gasket, I would recommend getting the RTV in caulk gun form and applying it that way. The gasket will be difficult to fit without it. The spark plug gaskets do not have this same problem.

Using the caulk gun is cost effective, and easier to apply a nice small consistent bead! Basically I ran it around all sides except the one with the half moons on it, installed the gasket, then laid it on the edge of a table with some weight on the cover. The half moon edge was the only part of the camcover not laying on the table.