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1996 Jaguar XJ6 Crank no start issue ( camshaft sensor)
Hello all!
I might have a doozy for you. have a 1996 Jaguar XJ6. I was originally told the fuel pump needed replaced due to cranks but no start. If I use starter fluid it will start but shuts off. You can however hear the fuel pump hum when the key is in the on position. I originally thought it was the initial switch. Which I do not think it is any longer. If it started with starting fluid, by theory of deduction i have spark. I did have to replace the battery because it died so I'm though security was tripped not allowing fuel to the injectors. Which would have activated that switch. I do not have any flashing key symbols.
Today I got to dig alittle deeper and found that I am getting fuel, fuel pump is kicking on. So that rules out the Inertia switch. I forgot I had the engine code read ( P0340) before I parked it. I believe this to actually be the issue. Please see the attached photos.
Where is the camshaft and/or crank position sensor located? I've been searching and on other forums they say if I have the 4.0L there is no camshaft. On part websites they sell the cam shaft so I am entirely too confused. Please see the photos attached!
For 1996 you will have the AJ16 engine with a camshaft position sensor ( PO340 ) where the old distributor cap was on the fwd right side of the engine , hockey puck with a small round window
In the starting sequence the fuel pump will run for 3 seconds only
It will trap this pressure until the front of the engine pully crankshaft sensor ( P0335 ) sees engine rotation, safety design , AND THE FUEL PUMP RELAY CLOSES FOR THE DURATION OF YOUR DRIVE
So you will feel 3 clicks of the fuel pump relay on - off - on
The camshaft position sensor ( P0340 ) is only used in the beginning of the start sequence and then the crankshaft sensor take over
You can have the camshaft sensor connector off and the engine will start with a few engine revolutions
There is an adjustment to the CMPS as you are getting it's code to replace but you can get that later ( I would leave the adjustment alone for now ) at the local parts store where I found mine
To get your car started you can jumper the fuel pump relay from socket 3 ( power ) to 5
This will drain the battery with the keys in your pocket as socket 3 is hot at all times
There is a secret fuse which is the control power of the fuel pump relay as # 10 right heelboard fuse box , THIS WILL BE POINT 7 DOUBLE HASH CIRCLE ON THE BELOW PIC
For this fuse to be powered the relay in the corner of the fuse box must click closed on key rotation to run , you can leave the key in run and remove the relay and it should click back to the open / relaxed position , it can be swapped with the left engine bay fuse box , only controls the car horn
The crankshaft position sensor can fail in the fuel pump enable and not give a PO335 code
Age of fuel as verry sensitive to wanting fresh , water can get into the fuel by the fuel cap in the well that can fill with water , just a bad tank of gas from the last fill up can be trouble
If your fuel pressure regulator is bypassing too much fuel you can pinch off the rubber return line to the fuel tank as a short start
if you remove the vacuum hose on the fuel pressure regulator it should be dry and not leaking after a fuel pump run
There are 2 power sources for the Engine ECU , the right engine bay fuse box relay ( ignition positive relay ) and the large right # 5 ECU Controlled relay which directly powers the fuel injectors
You are getting the first one sinse you have spark plug ignition
This large relay can be swapped with a headlight and such of the same part # as there are several large of the same part #
You do have a cold engine coolant sensor that can be left alone to start your engine and look at later for when the engine warms up and goes into closed loop engine regulation
The engine normally starts in the cold engine coolant open loop mode
To take the secondary air pump out of the picture you can unplug it leaving the 2 wire engine coolant sensor alone
See page 54
This Doc is in 3 sectiona AJ6 , V12 , and what you have the AJ16
The first thing I would do is swap the large Right # 5 ECU controlled relay to ensure the fuel injectors are opening
Second would be jumpering the fuel pump relay
Third insuring you have fresh fuel
Leaving everything else alone
The large ECU control relay can be stuck in the socket holder base and can be flipped upside down and sprayed in the joining seam halves with some penetrating spray
there is a waterproofing O - ring in the seam that can bind
The initial no start condition the previous owner may have experienced is a bore wash condition where the cylinder walls are stripped of ring sealing oil not allowing compression to start
This can be from the car sitting and is common in that case
It can also accure from short engine runs
you can remove the plugs and pour a penetrating oil into the cylinders to let soak and reestablish your compression for a start
It will smoke as it burns off but is a smoke of joy
your starter spray can be overcompensating for this condition and give you the short light off
I read the codes again. I now only have P1157 and P1138 "HO2S sense circuit lack of “swing” – cylinders 4, 5, 6 (B bank), downstream (2) Sense circuit indicates lean combustion (No HO2S response)". I opened the fuel cap and low and behold... there was water in it. Fuel cap is worn. I'm going to drain the tank, replace fuel filter, and go from there!
Some of the X300s you can siphon from the fill cap with a 1/4 inch hose of 5 foot length , some have a anti siphon trap below the unleaded nozzle trap door at top of the fill cap
Plenty of glass jugs at the glass recycle bins
with the fuel filter off you can pump it out by jumpering the fuel pump relay to get the last bit out not siphoned
The fuel filter is just behind the left rear tire
on the fuel filter the flow is from inboard to outboard
The tubing wrench is a common 11 / 16 if I recall , a crescent wrench can hold the other fitting , you're not going to get much of a swing
There should be O - rings recessed down in the filter end fittings
there is a cap well water drain line that gets clogged and is common
on fresh fuel cycle the key several times as this would push through pass the trapped fuel in the engine lines into the Fuel pressure regulator return line back to the tank
Your O2 sensors will not be used until the engine coolant reaches 88 C and the codes may disappear as a nuisance flagging
So you can start it regardless of the O2 sensor codes
If there was water in the fill well this can affect the security lock control module located below the well if the water gets pass the well upper rim seals to the rear quarter panel sheet metal
Some of the X300s you can siphon from the fill cap with a 1/4 inch hose of 5 foot length , some have a anti siphon trap below the unleaded nozzle trap door at top of the fill cap
Plenty of glass jugs at the glass recycle bins
with the fuel filter off you can pump it out by jumpering the fuel pump relay to get the last bit out not siphoned
The fuel filter is just behind the left rear tire
on the fuel filter the flow is from inboard to outboard
The tubing wrench is a common 11 / 16 if I recall , a crescent wrench can hold the other fitting , you're not going to get much of a swing
There should be O - rings recessed down in the filter end fittings
there is a cap well water drain line that gets clogged and is common
on fresh fuel cycle the key several times as this would push through pass the trapped fuel in the engine lines into the Fuel pressure regulator return line back to the tank
Your O2 sensors will not be used until the engine coolant reaches 88 C and the codes may disappear as a nuisance flagging
So you can start it regardless of the O2 sensor codes
If there was water in the fill well this can affect the security lock control module located below the well if the water gets pass the well upper rim seals to the rear quarter panel sheet metal
Update!!
Siphoned what I could, Replaced fuel filter, added HEET to some clean fuel, and voila! She starts! But only with starter fluid. I can only get it to run at idle for about 20-45 seconds. Then it shuts off. Tomorrow I'm thinking I should just go ahead and drop the tank and replace the fuel pump. I can hear it prime, but it could be faulty and priming is all it's doing.
The security lock control module does enable the starter by way if the BPM
The SLCM is powered and hot at all times
With your finger on the fuel pump relay it should click 3 times on - off - on , the 3rd click will be above a certain engine RPM , the starter is 300 RPM
There is a crash switch that can be fickle and be jumperd with a wire at the connector between the 2 white wires
Your fuel pump control power is point 7 double hash circle , the same point in the above pic on post # 2
There is the troublesome BT 4 connector above the fuel tank that can become disconnected
When she runs at idle for 30/45 seconds, does she run cleanly/ smoothly? There could still be water in the fuel rail, pressure regulator etc, but I would expect her to run unevenly if this was the case. If she is running unevenly, I would keep repeating the starts till it burns through the system.
It didn't at first but after a few starts I can get it to start smooth and idle fine. I can put it in Drive and everything is fine. But as soon as I touch the gas pedal it shuts off.
I'm thinking there's still water and the pump is picking up the water at the bottom. But I am not totally sure the pump isn't bad either. So I'm going to check that out as well today!
The fuel pump will pump fuel fwd to the fuel pressure regulator and what natually bypasses the FPR goes back into the tank
So it is mixing the fuel for your
The fuel pressure should be 43 PSI.
Have you done a throttle position sensor check ?
in the driveway and you first put the transmission in gear there is a transmission body connector if dirty can interfere with the transmission ECU talking to the engine ECU as they dance together and corrdinate the activities
Can you hold a higher engine RPM in the driveway before shifting out of park ? this is not a test to see if can transition into a different gear with a higher RPM and not stalling but a stand-alone test if the engine can maintain a higher RPM.staying in the park position
This would be testing somewhat the throttle position sensor and mass air flow sensor.
This is your transmission connector on the left rear side without jacking the car
to remove the connector the barrel must translate aft about 1/8 th inch to unlock and only then twist off , notice the use of tie wraps to grip the connector barrel in someones Pic he took
As soon as I touch the gas pedal it shuts off. It holds a low idle and I can inch forward for about a second and then it dies.
I also noticed that if I hold the key in the door to the "unlock" position, the windows don't roll down like they used to. I saw this on another post as a potential fix"what you need to do is disconnect the ground from your battery and touch it to the positive lead on the battery for about 30 seconds, and reconnect the ground to the battery. This seems to work for a lot of people. What it does is drains all of the power out of all the electronics and forces the cars computer to reset itself, you will lose trip data (MPG, and mileage). Your odometer will be fine. Also, do not be alarmed if you do this and your car idles incredibly rough the next few times you start it. The computer simply needs to relearn the idle habits of the car and it will return to normal."
As far as this goes, does he mean disconnect the postive and negative terminal, and touch the ground to the postive term ( not the cable itself)?
Since you have a US model without the security lock out codes for your stereo head..................................
The Hard Reset only applies to the items that are directly wired to the battery like the SLCM and BPM
On the fuse boxes only the fuse # 10 ,12, 14 , and 16 are not directly wired to the battery., the rest are as is wired inside the fuse boxes bypassing the corner king relay
In the X300 case the engine ECU is not directly wired to the battery so no reset
Bring both battery cables together away from the battery post and hold touching each other with a tie wrap over night.
Since you have a US model without the security lock out codes for your stereo head..................................
The Hard Reset only applies to the items that are directly wired to the battery like the SLCM and BPM
On the fuse boxes only the fuse # 10 ,12, 14 , and 16 are not directly wired to the battery., the rest are as is wired inside the fuse boxes bypassing the corner king relay
In the X300 case the engine ECU is not directly wired to the battery so no reset
Bring both battery cables together away from the battery post and hold touching each other with a tie wrap over night.
Got it!! I'll give an update shortly! I'm going to check all of those things. Thank you for all the help!
I disconnect the battery terminals. And reconnected. I now get the alarm beep! When I go to start the car, I get nothing. Lock and unlock the doors with the key, no alarm beep but they lock. Car will crank no start again.
01-07-2023, 09:46 PM
1996 Jaguar XJ6 Crank no start issue ( camshaft sensor)
