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Thank you for posting those photos, frenchfairplaydriver! Perhaps in some markets the non-4.0L cars received electronic transmissions? I just looked at the diagram for the U.K. cars up to VIN 594575 and it shows both a pedal stop, part 12, and a kickdown switch, part 16:
All that to say, Terry, you may have a kickdown switch after all!
I can confirm my 1989 3.6l car does have this switch, and my car has the fully hydro-mechanical transmission.
I imagine this switch is not to command an upshift, but to tell the ECU to retard the timing, as to not send maximum torque through the transmission during a WOT downshift.
While I cant see the wires by simply lifting the carpet, I can push down on the switch and hear it "click" so to speak.
I tried to push the switch while idling in park, and then give it throttle, but it made no difference in run condition. However that was only in park...
Today I went looking for the TCM, it simply is not there.
The plugs are there; however, this is usually the case as the same looms are used across modules for the optional extras to be added at significantly inflated prices. For example; I have a sunroof plug in the top of the car but no sunroof.
There is also no signs of any part that would have been fitted there either. The plug is cabled tied back out of the way and it has a significant amount of dust over it and in it. It has now been cleaned as a result. No signs that a TCM module was present either as the sight to put it in shows no wear or scratches that would indicate something was there previously.
Additionally, the car has a transmission kick down cable fitted. [3 cables on the throttle body] One running back, to pull the cable during acceleration.
The switch at the bottom is non-existent. Just a plastic and oddly adjustable stump.
I do thank the members of the forum for their contributions on this idea though. I did investigate it and took it very seriously.
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Fingers crossed tightly that the CPS is what is causing the problem. A certified spare parts dealer is sending a new one, it should be here on Monday. Fingers crossed very tightly that it does the job.
Last thing on the list of things to investigate anyway.
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Thank you to all the members who have helped thus far.
One last thought, perhaps you've checked this already - but if not, might be worth having a look at the teeth on the pulley that the CPS "reads"?
AFAIK the CPS looks for a "missing" tooth to determine timing ...maybe the pulley has some damage or crap build-up on it that's interfering with the pickup signal? ... (final straw clutch from me )
3 - Remove the distributor and check the tensioner.
4 - Refit the distributor checking alignment marks, even though this ultimately is not a precision exercise as with conventional distributors.
Just reading a thread on another XJ40 forum ..."Engine Misfire" - similar situation?...
Apparently after I removed it I misaligned the splines when re-inserting it. The engine would run but under some situations apparently the ECU couldn't adjust the timing right and so it started to misfire and use too much fuel.
I removed the distributor, advanced it one spline and now the misfiring is gone.
I checked it out a few days ago, but have not played around with it yet.
The closest thing that came of it, was to accelerate and advance it back and forward. Did not make much of a difference aside from the extremes where it bogged down from firing between two points.
I decided today to move the #1 position on the distributor one peg to the left. Literally by drawing a chalk mark on the side to TDC1, and re-fitting the distributor. All the plugs were then re-arranged into the correct firing order. The distributor can be advanced or retarded about 30deg easily before it cuts out on either extream.
No difference.
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One way of getting the engine to rev seems to be to pulse the throttle. Don't particularly want to look like I am trying to kill a spider on the peddle just to get about town though.
If anything it proves that air/fuel ratio is good. It is just down to the electronic timing issue. Once up to speed in this fashion, the ignition at TDC is quite stable.
This concerns me as the new CPS to be fitted will not solve the problem at hand.
It is a timing advance and retard problem.
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As observed today yet again.
The application of the throttle seems to delay the timing about 40deg after tdc at its worst. The retarding of the timing is the problem.
Remaining things to check out will be to;
a) Check the throttle kick down the cable condition at the transmission end.
b) Continue investigating what plays a role in retarding timing on the 3.2l engines.
c) Install the authentic Jaguar CPS, which is on its way: [unlikely fix].
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Note;
The harmonic balancer actually has 3 slots on the reluctor, to fire the CPS and the ICM. All clean and free of damage.
There is also a small arrow on the harmonic balancer to help find TDC, on the timing peg on the engine block. Never noticed that before,...
Managed to find out that the reason why the cam-cover was leaking oil so badly was that it had a cable tie traversing its seal. Not sure how it got there, but that was rectified today as well.
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Summary
Need to find a way to electronically fix the retarding problem. Inspecting the way this happens and why will be the key to fixing the problem.
Today a massive workload was unleashed at the vehicle. This was in a last ditched effort to avoid putting in a transplant engine from another vehicle; such as a 350-chev. As the title suggested the work done today was successful.
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First up, the intake manifold was taken down and completely flushed. With that out of the way all of the looms was taken apart to the bulkhead where the wire was still flexible and not brittle. Some wires although conductive were replaced entirely to the nearest node inside or electrical connector. This included tapeing over the coaxial cable coating with aviation grade tape, past the injectors back towards the ECU. Then everything was put back together with great care and attention. Lastly, a Jaguar approved spare CPS was installed with a new style 3 prong connector replacing the soldered joints and avoiding the old style connector too. At the last moment, the car was pushed onto a host and the negative engine earth was inspected. The resistance was 0.01 ohm better. The transmission kick down cable was inspected, later replaced and adjusted. Then the miracle we all needed arrived. The car was drivable as normal again after the first key turn down from the hoist. I suspect that the cps was the problem all along; however, the car is in really good shape now.
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The CPS fault in retrospective.
Inspection proved it was on the maximum clearance threshold away from the relutor rotor on the harmonic balancer pulley. The readings were 1.26 ohm between the trigger wires, and 0 on the coaxial coating whilst testing for internal connectivity.
The new one was 1.52 ohm in resistance between the trigger, and the coaxial was 0 until it was hooked up. It then read 1.52 to earth. Which was the figure from + to - on the block whilst resting?
A theory could have been that the coaxial cable was not earthed in the old one. Either way it is a good measurable observation.
Overall the CPS was half dead and dying. I have learned that inspecting it electronically will do no good. You have to judge the car and its cps from its symptoms. One of the big ones seemed to be timing issues and the backfiring. As the sensor was ok to run at low speed but, at higher revs, and it died out ultimately in confusion to what the reluctor wheel was doing.
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In Summary; Use Jaguar authorised parts !!!
I am certain that the majority of the work done so far, often in odd directions is good preventative maintenance. However, everything came down essentially to the dodgy CPS I bought.
The cps that was in there was new and did function: somewhat. However, ultimately it was on the threshold when it was inspected. Lesson learned that the engines main timing, and running problems will come from here. So don't cheap out. Replace it and always have a new unused spare handy.
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Looking forward to getting a good summers worth of motoring in now.
Thank you to all the volunteers and gurus who helped resolve this one.
09-28-2017, 12:29 AM
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