Flattery will get you anything.

It seemed like you were getting a better response in the XK8/R section MR CJ but it is an XJ8 so I've merged the threads here, I've left a redirect in the XK section for anyone that wants to follow it over.

 

Quick update. I downloaded JTIS as suggested. Its a great resource, now I can do all kinds of other projects. I tested the ECM connectors according to the JTIS instructions. While I do have 12V to the ignition, the ECM itself seems to be bad. Where the JTIS says you should have no more than 5 ohms of resistance, the measured resistance reads infinity. I am confident that I am reading it correctly, because I have the multimeter set at 200ohm (tried 2000ohm too) and I can measure an accurate ohm reading on resistors with a known value. I suspect my ECM is bad. I also am getting a code P1638 (before I did anything with the ECM), and I can clear the code, attempt to start a couple times, and code P1638 comes back, referencing CAN Link / Engine Control Module Fault.
The replacement ECM with same part # is on order, and I hope to receive next week and try it out. I will provide an update as soon as I install the ECM. I hope that fixes the problem.

 

Did you check the Ignition relay in the control module enclosure?
Look on page 29 http://www.jagrepair.com/images/Auto.../jagxj1999.pdf

 

I had checked the brown relays in the enclosure and swapped all the relays with a known good brown relay. It did not change anything, so I think the relays are good.

I also took the starter relay and swapped it with the ignition coil relay and no difference, the starter still engaged and the car still did not have spark. I wish it was just a simple fuse, or a relay. I really hope it is down to just the ECM swap that will do the trick. I should know if the replacement ECM fixes the car later this week when the part arrives.

 

Are you saying that the starter engages the flywheel but does not turn the engine over? Check your PM

 

Did you try the multimeter 'both ways' - reversing the connection to the terminals?
I've no idea what the plumbing is like in the ECM but if there's a diode you will get infinite resitance one way (because the meter applies a small voltage to measure resistance and it won't go through the diode).
Just a thought.

 

The Crankshaft Postion Sensor (CKPS) will cause a loss of spark if it goes bad. I'm not sure of how to test it, but I have read posts about them failing and causing a no-start condition.

 

I replaced the CPS under the car and no luck. Hoping that the replacement ECM arrives soon and will resolve this problem! Can't wait to hear the car roar to life.

 

You've tried the cylinder wash trick that Sean B. mentioned ? Just a thought. It has been known to happen.

 

Yep, I am becoming a no-start professional. I have tried the cylinder wash, oil in the cylinder, trick too. Same no-start condition, and still no spark. I am down to the ECM, which should arrive this Wednesday, if that doesn't work, I have to go back to the drawing board. Issue currently still remains that I have 12V at the coils, but absolutely no spark.

 

I played with the multimeter a little more, terminals that the JTIS tell me to measure still have high readings with the probes tested both ways. JTIS says that readings over 5ohms = high resistance circuit failure. Also have a P1638 code that I can clear, try to start, and comes right back. The code relates to "P1638 CAN Link ECM/Major Instrument Pack Circuit/Network Malfunction" which, from reading more about, can be as simple as a battery disconnect when the car's ignition was switched on. However, I have never done this, and the code comes right back on when attempting to start after clear, without any change to the battery connections.
This code, on top of everything else that I tried, keeps pointing to three little letters, ECM.

 

Thanks, Gus. It was nice talking to you. Thanks for all of the tech tips on your site. It saves me a lot of time scratching my head. I can't wait to post a happy dance smiley guy when the car starts. It is so close, I can feel it...

 

Well, let us know when you've got a new brain in place.
Good luck, fingers crossed.

 

Have you tried re-seating the IPK connectors, they're at the base of the instrument pack, pull the veneer off drop the 4 screws out and disconnect-reconnect them?

 

HAS ANYONE HAD EXPERIENCE WITH RODENT WIRE PROBLEMS ON 98 xk8s and when it effects the computer and the ignition sensors and fuel system. The issue is more to the cost of the dealership to find the problem and if the fix is worth the value of the car. Can repairs without total system replacement work within the dealership policy and will the insurance coverage pay for it?

 

You would have a better chance of getting relevant responses if you posted a new thread with a accurate title.

 

UPDATE: I received the replacement ECM today (same Part #, same model year). I disconnected battery, installed ECM, reconnected battery. Went to the driver seat, turned the key, and nothing changed. :-( The car still turns over, has 40psi, fully charged battery, 12v at the coils. I still have NO SPARK on any of the 8 coils. (I removed plugs, installed in boot, grounded, had someone watch for spark when cranking, also had someone crank while I watched for spark.) I am still concerned that I have no spark.

I ran AutoEnginuity for all modules. I have the following:
U1135: SCP (J1850) Invalid or Missing Data for Ignition Switch / Starter
This code is specifically under the Driver Side Rear Door Control Module.
I cleared all codes, checked again, and U1135 was there again.

This code sounds suspicious. Especially since it has the word "ignition" in it, and that is what my problem is. What's next? Does the driver side rear door control module someone affect the ignition of the car, or in some way prevent the ignition from activating?

Can I somehow jump the ignition relay in the engine bay to see if I can get spark and maybe fire the car up? If so, what connection would I need to jump?

I am confident that the key is not at fault. I had a bad key on my XK8 and I would not have been able to initiate the starter, fuel, and have engine turn over, and the code would not be under the door module codes.

 

Have you checked or replaced the Crankshaft position sensor?

 

Yes, I had replaced that as one of the first things in hopes that it would fix the problem. It made no difference, but I kept the new sensor installed.

 

You said you purchased this car in a no start condition and if that is the case then was the car a repo? It could be that the key that you have is a new key that was not setup for this car or that the exciter ring may have failed and you need to replace it. The exciter ring is a cheap fix the key programming is not cheap and can only be done by a certified person Jaguar in most cases