Hello,

Just bought myself another Jaguar yesterday. It is a Green1999 XJ8 w/ 101k miles. I bought it at auction in "Won't start" condition, so I am not aware of the history of the car. What I do know is the following: Car appears to have been well cared for, there are many new coolant hoses, its a clean car, and there was an indicated of an oil change completed in January 2012 about 300 miles ago, so the car likely sat for about 3 months. However, when I first got the car, it would do nothing. Put in a new battery, and it turns over, but won't start. I checked all fuses in the engine bay and trunk, all good. I also inspected the relays, none appear burned or damaged. No loose wires that I found in engine. Fuel pressure tester shows a strong 40psi. I have an AutoEnginuity scan tool w/Jaguar expansion. With the new battery, and attemping to start, it will only show code P0102 related to MAF fuel/air mixture, likely a result of the engine not firing.

Next step, I removed a coil, put in a small metal punch in the boot, grounded it, but no spark when attempting to start. I will remove plug and ground to the throttle body to see if the plug will spark later today. I notice that fuel is pooling in the throttle body and appears to be in the spark plug area too, and I have had no indication of a spark. Just a strong, consistent turn, turn turn, turn (it sounds just like my 98XK8 when it tries to start). The battery is new, a charger is hooked to the battery as well. So, I think spark may the issue. Now, on to the steps of getting it started!

What components should I check (and, in the case of relays or other electronics, where are they?)
I've heard mention of the Crank Position Sensor. Does this control spark in any way? (I have put this part on order, just in case I need it)
What else can I check? all fuses are good, not sure how to check relays.

Thanks for any tips, can't wait to get this car running, it is so close.
Thank you, C.J.

 

On your '99, each ignition coil has 4 wires. First thing, confirm that you have 12 volts between the pink/white wire and the black wire on each ignition coil connector when the ignition is in the full on position.

 

How are you checking for spark? Has any work been done on the car lately? Has anything happened to the car that might be related?

 

I actually bought this car in "won't start" condition, so I don't know its history. I have put in a new battery. Car is otherwise in good condition, and has no evidence of tampering with any wires.

I checked for spark by removing coil (kept connector plugged in), insert spark plug, kept the ignition coil and plug grounded to throttle body, had someone turn car over many times, I looked very close and no evidence of spark on the spark plug tip. This was true for two coils/plugs that I tried, note that I tried with plugs from the car, and brand new plugs. Still no spark. I will have to check the voltage across those wires.

 

I tested every coil connector plug. I have 12V on all 8! This is good news. Doesn't this mean that I should have spark? Maybe my basic method of testing for spark was inaccurate....remove one coil and remove plug, insert plug in coil boot, ground to throttle body, check for spark in the gap while someone else attempts to start the car.
I just tried another way of checking for spark. I pulled 4 coils (one at a time), removed the coil boot, and rested the coil tip a few millimeters from the frame of the car where I could see it. Its late and dark, so I turned off all garage lights, turned the ignition key to the crank position, no spark at all on any of the 4 coils I tested, the coil connector still reads 12V. Could it be something else that I need to check?

I still have a new, strong battery at 12V and strong (consistent) 40psi fuel pressure. I have no Check engine light codes, just a wheel speed sensor code.

What's next?

 

Actually I was hoping you did not...that problem would be easier to resolve. You are going to need to check the other 2 wires on the coils between the coils and the ECM. It sounds like either there is a wiring problem, a connector that is unmated, or the ECM ignition circuits are bad.

A copy of JTIS would be very helpful for you at this point. See if you can download it if you do not have it.

 

Thank you for all of the suggestions, I am getting close, I can feel it. I will try to download JTIS for this car.
For the other two wires on the ignition coil connector, should I also see 12V With key all the way on, but not in crank position? or just see 12V when attempting to crank?
Would it be possible, in the case of ECM malfunction, that no relevant codes will show when I scanned with AutoEnginuity?
I will try and find a good ECM with matching part number on EBay. Looks like they are running about $100, I don't mind buying one to swap it out. In the meantime is there another electrical check that I can perform? Off to find JTIS.

 

Reading through the thread, you bought the vehicle in a 'no start' condition.

It's almost certain the vendor will have tried everything to get it going and the lack of codes probably means this included clearing any that were stored.

If this is the case, as the vehicle hasn't been started again, it explains the lack of relevant codes.

Graham

 

The other 2 wires have pulsed signals, which you really need an oscilloscope to see. JTIS does have an ignition troubeshooting guide, which gives you some resistances to to check on these lines, which could shed some light, however.

 

Your spark test method is fine, you do not have spark. The most likely suspects are the two ignition modules or the spark circuits of the ECM. It is unlikely that both modules would fail at once though. It is important to note that each module controls only two coils on each bank. I suggest pulling the ECM harness and looking at it carefully, cleaning the plugs with electronics cleaner. If this doesn't do it, try another ECM. There have been some problems with this symptom on the 97's and 98's and the cause has been the ECM's. A bad ECM could also be the reason for no codes.

 

According to JTIS, the '99 XJ8 that Mr. CJ has does not have the separate ignition modules. The ignition is integrated in the ECM.

 

I will hunt down a matching ECM on ebay and see it that might do the trick. I did remove all the connectors, cleaned them with CRC electronic cleaner, no change. If only the ECM is bad, and a replacement fixes my problem, I will be a happy man.

 

A shot in the dark...

I'm not sure if this applies to the electronics in a Jaguar or not but are you sure the key has been married to the car?

I say that because last summer I had a Ford Excursion (I call it my Fordasaurus) and my brother borrowed it and called me telling me the damn thing wont start. Turns over all day long but wouldn't start. It turns out that his daughter dropped the keys and the built in chip had broken off of the key. He discovered that the key was chipped, found the missing piece, super glued it back to the metal key and it's been running fine ever since.

This might be a question to ask one of the Jaguar super techs. How does the car prohibit starting if the key is not programmed to the car? Does it keep[ the fuel pump off or does it kill the spark?

Good Luck,

Barry

 

Hello

Did you hear a one click when insert key turned on ignition?
if yes check chassis ground to starter
I've experienced one click problem 2 years ago
the fix was cleaned ground cable connection because of plastic cover melted all over it is cable so there was no continuity.

I hope it helps....

Mrdigi

 

Sounds like bore wash - a small amount of oil in each cylinder and hold the gas pedal to the floor all the time you crank - maybe some ezestart in the throttle.

 

You won't see a spark if you ground the coil like that.
Remove a plug or use a spare one as you suggest.

 

Did some more investigation, down to no spark. I tried the plug in the ignition coil, grounded, in the dark, no spark. I discovered that ECM is where ignition control is on this car.

So, far, I have determined the following:
Turn key, no security light, all systems appear good, turns, turns, turns, turns, no fire.
I have a new, and strong, battery, always hooked to charger when attempting to start.
I can hear fuel pump run, I have 40psi fuel pressure at the rail, and I can see fuel entering engine.
I removed and installed all new plugs.
I have 12V on each of the ignition coil connections pin 1 & 4. I checked for spark many different ways, including removing coil, inserting plug, grounding, no hint of any spark at all when turning over.

I downloaded JTIS last night, the 4th possible cause of problem is ECM malfunction. I am definitely pursuing the no spark condition and will provide updates. I also ordered a replacement ECM (same part #) from eBay, just in case there is a problem with my current ECM.

 

Yes, I am positive the key is ok, it activates all functions of the car including starting, just no spark. My XK8 had a bad key, and all it would do is turn the lights on and electronics, and not even attempt to start. I think the ECM is my next bet. I ordered one from eBay, and also downloaded JTIS last night. Its like the Holy Grail for a Jaguar DIYer! The 4th cause of no spark, according to JTIS, is ECM malfunction. I found the section on how to test the ignition control pin resistance in the ECM. I will work on checking this tonight and provide updates.

 

Good luck, you'll need advice from someone on the Forum who knows more about ignition problems than I do. Post no 6 from Gus here has a fault finding chart for your car.
https://www.jaguarforums.com/forum/x...r-pulse-52963/

 

Hope you don't mind my saying but it is a Bad Thing to have the same subject in two posts.
I am replying to your original and only found this because I look at the XK8/XKR forum regularly.
It means we can't see all of the Q+A's for the problem.
Maybe a DemiGod should shovel the two threads together?