Hello everyone, as you can tell I’m brand new to this forum.

I want to apologize for the length of this thread although it’s necessary for the issue I’m having. Much thanks to anyone who replies in advance!

I recently purchased a 91 XJ6 Sovereign (93k miles) and am having a huge issue that’s driving me nuts. I’ll keep this as simple yet detailed as possible.

i purchased this car 3 weeks ago and it was starting and running just fine.
last week I was at Wells Fargo with the car in park and it suddenly bogged down and died. The car strarted right back up and was fine until 2 days later when it happened again. I let it sit for about a hour then took it around the block and I could barely even get it around the neighborhood without it dying while driving/accelerating multiple times in a 5 minute time frame. After several deaths, the car no longer starts at all. It cranks but no start. The car was throwing a check engine code: Fuel Fail 24. After reading up on these forums I kept seeing “ignition amplifier” so I figured that was the issue. I went ahead and replaced the ignition coil (new) and the car started. The check engine was still on so I went ahead and did the reset by disconnect the battery, waiting, and starting it back up. No check engine light. After 30 minutes the car suddenly bogged out and died again. Back to square 1. Also since I cleared the check engine code and the car can’t start to read for any faults, I’m not getting anything from the VCM besides it saying “PAD” which is referring to my brake pad sensor. Anyway Ive now replaced the Ignition module (used) from a different jag. (Note: the ignition module looked to be different but had same amount of prong connectors so i plugged it in anyway.) in the process of replacing it, I ripped the ground wire coming out of the small cylinder that sits on the same steel plate as the ignition module. I took the cylinder out and stuffed the ground wire back in and pinched it to ensure the ground was making contact inside. (Note: That ground wire connects to the ignition coil.) also in the process of replacing the ignition module i set my wrench on the battery and it made contact with the positive and negative which caused a gnarly spark for a second. I don’t think that messed with anything but figured I’d mention it. I’ve also checked the fuel pressure regulator by unplugging the vacuum line and there was no gas coming out so I’m assuming that’s good. I’m at a loss of hope and don’t know where to continue with this. This car is mint inside and out, garage kept 1 owner and I’d love to keep it on the road as I really appreciate these classic cars.

 

Try a new rotor first, see if that makes a difference.

Larry

 

Hopefully an admin will see this thread and move it to the XJ40 section

Cheers
DD

 

Next time it dies - try giving the fuel tank a good bang with your hand and see if it starts.

I had an issue on my 94 XJ40 where it would act like it was going to die then be fine. This was very intermittent so I decided to wait till it became more consistent. After about a year, it started to die every time it was bogging down, but would restart straight away, however this would only happen every 2 months or so. Eventually it was happening once a week, turned out to be fuel pump, died on me in the Wendy's drive through one day. Had to push it out of the way, gave the fuel tank a good bang and started straight away. Replaced the pump and no more issues.

Also, when its cranking, is the needle on the tach moving? Crank sensors give problems, will cause to die once hot and after they cool down, allows the engine to start

 

Also - have you updated any of the relays??

 

Also, when its cranking, is the needle on the tach moving? Crank sensors give problems, will cause to die once hot and after they cool down, allows the engine to start[/QUOTE]
I will double check when I get home to see if the tach moves, the fuel pump wasn’t making any noises when I turned the key so I unplugged the relay and plugged it back in and the fuel pump turned on, would that be a sign of a bad pump?

 

I agree about banging on the tank to impulse iffy pumps, although IME fuel pumps that develop dead spots tend to fail on start rather than on run, although anything is possible.
If we are dealing with an electrical rather than a fuel/air issue and you need to check your crank sensor, JBzXJ40 has given you a good way to get an idea if it's OK by looking at the rev counter ...
The rotor on these cars is not your "normal" rotor - it has an electronic component embedded between the pick-up and the distribution terminal. That electronic component goes high resistance occasionally and a failing unit will cause running problems and no-start conditions.

This rotor is reasonably priced, RockAuto has a selection of them from US$8 to US$14, but I think you will find they are all the same and probably re-branded FACET units made in Italy, so pick up the cheapest - the FACET.
Even if your problem isn't the rotor, every XJ40 driver should keep a spare in the car as this thing will stop you dead in your tracks if it ever fails.
Stopped me twice over the years.

Good luck

Larry

 

Crappy blue HELLA relays are a known fault!!!!

Thanks for reminding me!

 

Thanks again for everyone who responded ! It doesn’t go unseen!
[UPDATE]: I had my buddy tap the fuel tank and the pump while trying to crank, still no start. I forgot to watch the tachometer as well, stupid me. One thing I noticed is the fuel pump wasn’t turning on while having the key in ignition 2. The other day we didn’t hear it so I unplugged the relay and plugged it back in and the fuel pump made noise. Today it was dead silent, even after unplugging and plugging the relay back in, still nothing. I went ahead and bought a aftermarket fuel pump and relay. I put the new relay in and still nothing. Tomorrow I will be installing the fuel pump and hopefully that has been my issue. I will post the results.

 

Hi Matt,

Welcome to the Jaguar Forums! It's great to have you with us, and we look forward to some photos of your Jag!

That small cylinder mounted at the ignition module is a noise filtering capacitor, and it is highly unlikely that you were able to repair it by stuffing the wire back in. It's a non-essential component that just helps reduce radio frequency interference (RFI) from the ignition. But if you find you are having interference in the radio you can probably find a generic filter capacitor to replace it with.

Cheers,

Don

 

Thanks don, I was losing my mind over that thinking it was something important. Here’s a few pictures for whoever is interested

 

UPDATE: So yesterday I attempted to replace the fuel pump. Once I had it removed out of the tank and went to put the new one in, I realized orileys sold me a import-direct fuel pump and there’s no way it will work in this car considering it’s 2.5 sizes bigger than the original. Today I will be ordering the right one. Soon as it’s installed I’ll give another update
PS: instead of removing the gas tank for this project, I cut a square in the center of the metal of the car where the 6x9 speakers would usually go to gain access to the pump. (Behind rear seats under rear window)

 

I currently have a FF24 code as well, haven't looked into as my car runs good. Putting the cat down to do some hose replacement now. But I did have an intermittent stall awhile ago, what seemed so solve it was cleaning of all the grounding points and relays and also cleaning of the CPS sensor.

 

For some reason there’s a list of issues that can throw a FF24 Code, not sure why it doesn’t direct you to one specific issue like the rest of the codes but it would be nice to have a list of what causes FF24 for easier troubleshooting

 

So after replacing the fuel pump I’m still not hearing it turn on and the car has a quarter tank of gas. Also when cranking the RPM needle is not moving , I’m assuming that leads me to the Crankshaft Position Sensor, but why would I still not hear the pump? It has a new relay as well. I wired it correctly with new prong connectors that the wire slips into and you crimp the wire into it so I don’t see how it wouldn’t at least turn on. I may have to take this to a British mechanic Wednesday because I’m getting too frustrated with this lol, again, all replies are very much appreciated

 

This might be a long shot, but have you tried resetting the one switch under the dash? I forget what its called but its the switch that activates when you get into a crash? I think this car has it, if I'm remembering correctly

 

The “inertia” switch?

 

I’ve located the Inertia Switch, which turns out to be a switch that shuts off all power to the fuel pump in the event of a accident. I’m not sure how to tell if this has been tripped or not and would rather not mess with it and cause more issues. I assume it hasn’t been tripped considering the push-pin isnt sticking out. This car has also never been in a accident.

 

Ya, that's it. Just push that button on top. You won't hurt anything if it isn't tripped.

 

thanks Jerry. I pushed the pin downward but the pin is already pushed in. Assuming that mean it’s not tripped. When I pull it upward the pin exposes more red which I assume is to signal you that it’s been tripped. Therefore this pin has not been tripped in my car.