When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi all my name Jason and thanks for your time,I've aquared a 1995 xjr by play pool.its a very Kool car but I've owned a couple years an its bin a nightmare trying to get it running.it ran when I got and one I moved it to plow and quit and hasn't run since,I believe the original problem was line off pump in tank.it sat for atleast a year,so I the pumps wer sized and the injectors,I replace them and fuel pressure regultor.still nothing,so I dug alittle more and found I had lost injector pulse,I replaced the crank sensor and cleaned the blancer,still nothing.so I cleaned every ground and connector I could find and replaced the ecm,o and starter,probably because I've bin trying to start it.so now I've got lost of fuel spark.the injectors are pulsing great.so I changed the Oil a put a st of plugs in it fig finally its going to start and nope it offers then make a horrible sound like back fire,anyway long story short I'm thinking timmings off but I can't find anything on how to set it,I really hope someone reads this and helps me out,I'll mail ya a bottle of scotch if it runs agin, I'm just about to give up and cut my losses,it would be a real shame the rest of the car is in pretty good shape, thanks for reading either way and I hope u all are safe an sound . Happy Easter 🐣
Jason,
It sounds like you have already done many of the obvious things, and if she was running when you got her, it should be possible to get there again.
You havent mentioned scanning for codes, and if you can, this would make sense.
Two other thoughts occur to me: low battery and contaminated fuel. Even if she will turn over on the starter, unless you have a healthy battery, she will not start. You mention some sort of backfire, which would make me wonder about fuel contamination, especially as she has been sitting for a while.
From what you have said, I wouldnt think it is timing, as nothing you say you have touched would affect it
Agree with @countyjag that unless you have done engine work it's unlikely the timing has moved. However, if you want to check it, it's straight forward.
There is a timing mark on the crankshaft pulley. It's a dot on the face of the pulley (not to be confused with the missing tooth on the pulley which is for the Crank Sensor). There is also a pointer on the engine block that the dot should align to at TDC. The pointer on the block is just below the Crank Sensor. It's very hard (impossible?) to align the dot and pointer accurately in situ, so for complete accuracy I use a long bar through the spark plug hole on No. 1 cylinder, and measure when the piston reaches TDC - ideally with a Dial Guage, or just trust the sensitivity of your fingers.
There are cut outs in the Camshafts at the front end, just behind the first cam bearing. When No. 1 is TDC on the firing stroke, the cut outs in the Camshafts should be at the top. There is a special tool to insert in the cut outs to confirm this. The tool is widely available and cheap. Search AJ16 Cam Locking Tool.
If you find the timing is out, you will need to adjust the Camshafts. That's a bit more involved. Let us know how you get on first.
Old fuel or a bad fill up from a couple of years ago , fuel can be siphoned from the fill cap , at least on mine
During starter rotation the voltage on your gauge should not get below 11.4 volts to properly power the ECU
CEL codes ?
when you rotate the ignition key the # 1 fuel pump will come on for 4 seconds then off
This will trap 43 psi in the fuel lines for starting then the pump will turn on again for the duration of your drive
You can swap 2 relays that power the ECU
Right engine fuse box for left engine fuse box
# 5 right large ECU controlled relay with a headlight ( same part number )
Right heelboard fuse box relay with the left . the fuel pump control power comes from there fuse # 10 / 5 amp
someone had a bent pin in the OBD 2 connector which shares this # 10 fuse
Jumper the # 1 fuel pump at he frd most socket , Pump will run at all time with keys in pocket so plan accordingly
The camshaft sensor CEL code p0340 aids in the engine starting with few if any rotation
It is a hall effect sensor different then the inductance sensor for the crankshaft
It will read about 600 ohms as a fundamental meter reading different then 1300 for the inductance
Do you have a Andy bracket on the crankshaft sensor ?
Last edited by Parker 2; Mar 30, 2021 at 11:06 AM.
I got it running, but cant get it to Rev and exhaust is red, surpriit didn't catch f
Originally Posted by countyjag
Jason,
It sounds like you have already done many of the obvious things, and if she was running when you got her, it should be possible to get there again.
You havent mentioned scanning for codes, and if you can, this would make sense.
Two other thoughts occur to me: low battery and contaminated fuel. Even if she will turn over on the starter, unless you have a healthy battery, she will not start. You mention some sort of backfire, which would make me wonder about fuel contamination, especially as she has been sitting for a while.
From what you have said, I wouldnt think it is timing, as nothing you say you have touched would affect it
Old fuel or a bad fill up from a couple of years ago , fuel can be siphoned from the fill cap , at least on mine
During starter rotation the voltage on your gauge should not get below 11.4 volts to properly power the ECU
CEL codes ?
when you rotate the ignition key the # 1 fuel pump will come on for 4 seconds then off
This will trap 43 psi in the fuel lines for starting then the pump will turn on again for the duration of your drive
You can swap 2 relays that power the ECU
Right engine fuse box for left engine fuse box
# 5 right large ECU controlled relay with a headlight ( same part number )
Right heelboard fuse box relay with the left . the fuel pump control power comes from there fuse # 10 / 5 amp
someone had a bent pin in the OBD 2 connector which shares this # 10 fuse
Jumper the # 1 fuel pump at he frd most socket , Pump will run at all time with keys in pocket so plan accordingly
The camshaft sensor CEL code p0340 aids in the engine starting with few if any rotation
It is a hall effect sensor different then the inductance sensor for the crankshaft
It will read about 600 ohms as a fundamental meter reading different then 1300 for the inductance
Do you have a Andy bracket on the crankshaft sensor ?
no I'd don't but I'd really like to .i want to rebuild s/c and get pully upgrade ,I've also bin trying to get an ecm remap. Hard to find
Anyone that's does it.o
Hello Jason
I had a 95 XJR with a very similar symptoms, it was a running car for several years, and then no start. It taunted me for several years. I did all the stuff you have done and got the same results. It would crank and crank, backfire through the intake. Rarely it would start and kind of idle, but would rev and then die.
Eventually, like you I came to the conclusion that it had to be cam timing. I found a post on this site about with the motor at TDC using the front pulley. if you looked in the oil fill and looked at the #4 intake lobe it should be pointing more or less straight up. And mine was not. A halalula moment, as at least I found a reason after 2+ years. Now to the cause. Timing chain was intact, and my cams were way, way off. So they could not have possibly jumped that many teeth.
What I found was the key on the crank pulley had completely sheared allowing the timing wheel on the pulley to rotate on the crank by about 100% so of course it would not start. The computer was firering everything 100% off.
As an aside you would be shocked how small and feeble the key is on the XJR. It is tiny, ridiculously tiny. And it has the full load of pulling the supercharger.
The V12s have 2 keys and they are easily twice as big and thick. But yet the XJR makes more torque and is pulling the supercharger that can a fair amount of horsepower when you are working it.
So there you go, I hope this helps. And something every R oner should be aware of if you ever have a running car that suddenly acts like it is out of time. Suspect the tiny crank key
Xjr from hell
