Good day chaps! I'm still muddling my way through my 86 VDP but making decent progress. I can now push the engine all the way to what I can reasonably assume is redline (the tacho is useless for a true indication) before shifts and it's not stalling on me as much. I'm still fighting the urge to kick the TBI into orbit and replace it with a carb but an approaching northern US winter has kept my common sense in line. Like it or not, my Jag is a daily and I need to keep it that way.

Given the aforementioned approach of winter, here are my most urgent issues with which I could use some group thought.

1) My shifter detents are still way out there. I know that for the most part my shift tower is the stock XJ tower. The bezel, lever, etc are what you would expect to find in an ordinary SIII XJ. Where I become confused is what I'm going to call the detent plate. The little notched piece of metal that provides the positive shifter positions. Are these typically left stock when a car is lumped or do they get changed out? Does anyone know? Presently, mine locks into park (albeit with a good amount of force required), shifts into a spot between reverse and neutral which results in a horrible clicking from the trans, shifts into a solid reverse, neutral and then drive (overdrive?). It runs out of notches at this point leaving 2 and 1 unavailable. It's worth also noting that outside of park, all of the points are indicated one too low which also makes me think the plate is wonky. Why is this a problem? Well, primarily because when it gets really cold the shift cable seems to either ice up or stretch and the lack of movement at the bottom end causes difficulty or near impossibility getting the car into drive. It was too windy to feel comfortable putting the car in the air today but the next chance I get I'm going to look at cable adjustment. Any other thoughts would be met with great thanks!

2) The trans clicks in drive when rolling forward at slow speed. It's not loud enough to hear inside, it's only noticeable with the windows lowered. It's definitely a repetitive click almost like a gear that isn't quite fully engaged. It actually reminds me of my motorcycle when the primary slips out of adjustment and the chain pops when in gear, clutch in. I've rebuilt many manual transmissions but I will admit to being a bit out of my element with autos. This is only the 3rd autobox I've owned and I'd trade it for a manual in a heartbeat if that wasn't a major undertaking. Anyone with any expertise in the R4/4L60 who knows what might cause this, I'd love to hear your thoughts!

Those are my major concerns. Otherwise the big cat proved itself a capable winter warrior last year and I don't expect much issue with it this year. Knowing I do have my Saab to fall back on this year is also encouraging. I'd love to keep the kitty off of the road to avoid further rust issues but I've come to terms with the fact that I did not buy a garage queen and as pretty as it is on the surface, it has some issues underneath and I'll just have to face them and fix them as they require. Why own the car at all if I'm not going to use it, I reckon.

Thanks again all!

 

As to the detent plate, the answer is both ways. Or even three!!

In keeping the XJ 6 shift tower, the detent must be aligned with the transmission position via cable adjustment. There is clamp that clamps on to the cable swaged metal,
Place lever in park and undo or loosen the clamp. place the lever in park. tighten the clamp. Now, the lever should move rather nicely in most positions. Some do not have enough reach to get to the 1 position. A minor annoyance as most of us rarely need low to drive in.

Access is via a plate on the left die of the console (LHD) cars and probably RHD as well. Or get under as the plate acess is tight. Now the BW detents and the GM detents are close, but not quite.

Cables wear and get sticky. and have a habit of parting in inconvenient places and times. I was an exception, mine popped in my driveway during the lump process. I installed an improved model and all is well.

I swapped in an XJS shift tower. it has GM detents and needed switches, n/s and reverse lights.

The BW detent has annoying notch to some requiring a lateral movement as well as to and fro, some grind it away and allow smooth fore and aft. it doesn't bother me.

Beware of placing the trans in park and against a curb. the force needed to overcome a bind may snap the shift cable.

Your tach is getting six cylinder pulses and needs 8! They can be fixed, but, I don't know how. Jaguar Specialties or John's cars can do this for a fee.

 

Thanks JagCad!
It sounds like my car has the Borg-Warner plate still and the builder just did a slapdash connection of the cable to call it good (this is no surprise at all with this car as 90% of the mechanicals are slapdash). Given that it has the lateral gate at neutral and lacks functional reverse and neutral switches. I actually kind of like the lateral movement in the shifter except for the sloppy shifting of the trans in general. I feel it gives the car a little more quirk. Quirk, I can live with.

The lack of complete low is fine but I would like to have the option of pulling out of overdrive to save my brakes on steep grades. As for the cable, I've not had it bind on the top end, at least not in a way that it wouldn't come out of park. I have had it stick several times where the trans is in park but the lever isn't quite far enough forward to engage the park switch. Always good for a mild infarction when you attempt to crank the engine.

As for the tacho, I've had it apart and checked that it had the necessary added resistors to calibrate it. It does and it very closely matches a connected outboard inductive at idle. It's only at high revs that things go pear shaped and truthfully with all of the unknowns on this car I don't intend to drive it at high rev too much until all of that is sorted. Likely I'll just add an aftermarket tach somewhere inobtrusive once I get it to the point that I'm more confident in its mechanical soundness.

 

YUP!

Get under and align the cable and tower and you will be a happier man.

Adding a N/S inhibitor is not hard. Just a micro switch. The reverse is an XJS part and can be added to the side of the tower. I have a modifies XJ6 tower in my bits. If you are interested, contact me PM.

The tacho is running off ignition pulses as you know. So, if the ignition is acting up, so will the tacho. That connection thing again!! My tach is just fine, I drive by it as my speedo is nuts. I know how to fix it and have the part, just inertia.

Mine goes in for SMOG in a day or so. Purrs, so it should be just fine. I take a freeway run to heat the converters good and hot.

Retarding by the trans on steep hills, not so good anymore. Disk brakes are well capable of the task, unlike the old days. And brake pads are easier to install than transmission bands!! But, not preaching, merely commenting. To each his own.


Carl

 

Appreciate the thought of the modified tower, but I've dealt enough with adding micro switches into odd things in odd places. I reckon I can get mine sorted. I had a brief look at it this morning and I can see there are actually several switches in the housing, they're just not hooked up to anything. Probably an unfinished part of the project.

Ignition messed up? My car? Surely you jest! I do have that very, very dodgy harness running to the distributor that I'm certain is not helping matters. I'd be willing to wager the tacho is connected into that bodged up bit of hackery.

As for retarding by trans, I suppose that's an "old habits die hard" issue. Part of my desire to have that ability in the Jag is the present state of the brake system. Simply put, it needs a complete rebuild. Of major concern is the warped rear rotors which were developed when the brake pedal was being held partially depressed by its helper spring and keeping the brakes engaged during driving. This was shortly after I'd bought the car in barely running condition so I (wrongly) assumed it was just another manifestation of the engine's poor attitude and smoked the rear brakes. Most likely, once I get all of that sorted I'll be much more comfortable.

Good luck with your SMOG. That's one thing I'm very glad I don't have to deal with.

 

Thanks. It passed. perplexed the tech for a bit. Exprected a straight six and viewed a V8. but, i showed him the decal on the rear door with the barcode he needed to run the checks. The locked gas caps got him. So, I snuck by the vent leak test!!

A shift tower for a GM trans needs three switches. A green one on the side for reverse lamps. One micro on the front for the N/S interrupt. And another alongside for the cruise interrupt. Te tower can be essily opened to add the needed micro for the N?s or if cruise isn't in use, adjust it. It merely completes the ground leg of the starter relay.

The reverse lamp switch is a little tougher, but quite doable.

Yeah, redoing the ignition harness would probably do wonders. Start with the S57 scematics fopr the Jaguar way and adopt to the GM needs. Quite similar.

Fun, isn't it.

Carl

 

Good deal! I did that to a tech in Ohio with my old XJS. Even though that was obviously a V12 car, he had it in his head all Jags were inline 6's and was flabbergasted to see the big 12 under the bonnet. I lucked out on that one and was largely exempt from the tests because that was the day the distributor on the right bank decided to seize. Raw petrol pouring from the tailpipe didn't do me any favors. They passed it on the promise I'd fix it but made me tow it home. I traded it off on a 2003 Merc C230K Kompressor coupe and thought I was doing great until the first of 3 times it shed the rotor seals from the supercharger into the inlet tract of the engine.

Anyway, back to the proper subject, I'll be back to trans issues once I've fixed the slightly more pressing one. The passenger fuel tank ruptured yesterday. The really curious part of that is that I had fueled it up on the driver's side the day before. I guess I have some decoding of the bodged-up fuel system to do now... and a rusted tank to patch and seal.

 

I'm having similar fuel issues in mine. BOTH fuel pumps are leaking. Haven't figured out if I should replace both pumps or put in one pump with a switcher valve.
Is this tank repair an easy one? I'm sure replacement tanks arent cheap.
That transmission noise you referenced reminded me of a repair I did on a customer's 70 Chevelle. The parking pawl spring broke, which allowed the pawl to drop into the path of the output shaft, making a clicking noise. It was a pain getting the broken parts out, but with a new spring it was fine.

Hope the repairs go well. I'm hoping mine do, too

 

That's really odd that it has two pumps. By my reckoning, I would be replacing it with a single pump and a switcher. I still haven't sorted the bloody mess out that exists with mine. It's a single pump and parts of the stock Jag fuel lines but it has a crossover line between the two tanks, probably still the factory switching valve, etc, etc. It's a total bleating cluster flog.

The tank repair should be easy... as easy as any other tank repair anyway. The tanks on these Jaggies are really simple to drop. Just disconnect the lines, remove the lower valance, a couple of fasteners and out she comes. Where it gets messy is the same as any other weathered and broken tank; how do you clean it and how do you patch it? Acid works a treat on rust but it's a bugger to dispose of. I reckon I'm going to try electrolysis. I've done it on a bike tank and while it took two or three sessions, you just end up with rusty water as a byproduct (well, that and a little gaseous oxy and hydrogen). As for patching, I'm hoping I find a hole in a convenient place for an epoxy weld. Otherwise, I guess that's another benefit to using electrolysis to strip the rust; it should neutralize the fumes enough to allow a quick braze or buzz weld.
You're correct about the replacement tanks. The cheapest I've found have been $400 a pop. While that's not totally out of the realm of possibility, I can think of a lot better things to spend that kind of money on.

Best of luck on your repairs. I'm hoping to begin my undertaking this weekend so hopefully I'll have updates on the progress.

Cheers!