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Doug
if I understand your first reply in post 19 above correctly, the engine oscillates with your foot lightly ON the throttle? If that id so, does this happen only with the new red Jaguar TPS?
Doug
if I understand your first reply in post 19 above correctly, the engine oscillates with your foot lightly ON the throttle? If that id so, does this happen only with the new red Jaguar TPS?
Yes, if I just barely crack the throttle open the wild behavior begins and yes, only with the new red Jaguar TPS.
At the risk of a brick on the roof, even from PNW.
You do have that slack in the throttle rods. to allow the electric bit to be slightly ahead of the mechanicals.
About 1mm. Should I increase that a bit?
Would be interesting the split volts of both TPS units when this is happening. .50v seems to ring a dull bell as the magic number.
Not following you on this, sorry !
I've returned the new red TPS...which I believe to be defective. The vendor will send another. We'll see what happens.
Although the engine is running fine with the Mustang TPS I have to wonder if it is masking a different problem.
Hopefully I'll have time tomorrow to really roll-up my sleeves on the high idle thing. I have that funny feeling that I've overlooked something simple and obvious. Wishful thinking, maybe? This...all these problems....began after I replaced the vacuum advance canister. The high idle is present even with the vacuum advanced unplugged. But I haven't checked the timing. I wonder if, somehow, in the process of changing the cannister, I did "something" to advance the timing? I replaced the canister with the dizzy in situ. But adding advance would certainly increase the idle speed.
I use a 2mm spacer when setting the 2 rods. Not sure on 1mm, but too tight and "stuff" does happen.
By the split voltage I mean to leave the DVM attached after the thing is reassembled, then when the "stuff" happens, note the voltage, maybe a dud TPS, which I know you have now returned, so highly probable.
Timing is a good suspect, as I have had some of those capsules with SLIGHTLY different length pull rods, and 1/2 mm shorter there would advance the timing a good few degrees.
Doug,
Please excuse this point if already checked! As you have eliminated the AAV, and as you have had the dizzy apart, how are you arranging the dizzy ventilation? And is there possibly an overlooked air path because of that?
Doug,
Please excuse this point if already checked! As you have eliminated the AAV, and as you have had the dizzy apart, how are you arranging the dizzy ventilation? And is there possibly an overlooked air path because of that?
The distributor vent that was on the AAV hose now goes to the back side of the LH air filter housing.
I would focus on the advance issue. Suppose that even with the hose off,, the unit or the linkage pulls an advance in the distributor. Unhook the link and see if the is is lower???
I would focus on the advance issue. Suppose that even with the hose off,, the unit or the linkage pulls an advance in the distributor. Unhook the link and see if the is is lower???
I'm sure leaning in that direction, Carl. I'm running out of places to check for vacuum leaks.
You guys are gonna love this...on the basis of "....and the hits just keep on coming"
Checked the timing. At idle it shows 20º retarded! The engine is running way too well for that to be accurate so my assumption is that my balancer is delaminating ! Oh well, one more thing to fix. Wonder how long it has been that way?
Just for the heck of of I did retard the timing just a bit and the idle dropped a bit.
It also dawned on me (better late than never, right?) that this is an adjustable vacuum advance. I installed it straight out of the box. I'll look into the adjustment and how it works. There were no instructions. Looks like a locknut and a screw. If I turn the adjuster screw I'm not sure what I'm actually moving inside the capsule. Maybe the length/pull of the little pushrod? If that's the case, maybe I'm onto something....in light of Grant's and Carl's remarks of varying length push/pull rods? If that's the fix I'm gonna feel really dumb for not thinking of it sooner.
Meanwhile the car is driving like a dream so I'm enjoying it a lot.
Tempted to leave it be. don't fix what don't need fixing?
Think back to GM days., Teh Allen head in the vacum spigot on the diaphram.
Two means of doing the same thing., Preset the position of the diapphram?
I guess finding TDC on the V12 by the rod in the sark plug hole is easier said than done. Confrm the timing mark or dispell it..
Mark it and watch? Still moving or found a set.
Way back when the dampener on the 292 in my 61 Ford delaminated completely. .
I had been working in Las Vegas and needed to get home in LA. I limped in.. Easy on the gas or get an awful screech ! Made it. fixed over the week end as I had to return to LV and continue to be the temp claim manager there... It was fun... No gmbling, but got to see some shows...
You guys are gonna love this...on the basis of "....and the hits just keep on coming"
Checked the timing. At idle it shows 20º retarded! The engine is running way too well for that to be accurate so my assumption is that my balancer is delaminating ! Oh well, one more thing to fix. Wonder how long it has been that way?
Just for the heck of of I did retard the timing just a bit and the idle dropped a bit.
It also dawned on me (better late than never, right?) that this is an adjustable vacuum advance. I installed it straight out of the box. I'll look into the adjustment and how it works. There were no instructions. Looks like a locknut and a screw. If I turn the adjuster screw I'm not sure what I'm actually moving inside the capsule. Maybe the length/pull of the little pushrod? If that's the case, maybe I'm onto something....in light of Grant's and Carl's remarks of varying length push/pull rods? If that's the fix I'm gonna feel really dumb for not thinking of it sooner.
Meanwhile the car is driving like a dream so I'm enjoying it a lot.
Cheers
DD
Doug,
Its all the joys of V12 ownership.
You need more coffee mate, too much thinking been going on.
If its running as you say, and you have that V12 smile on your diall, worry not for now. There will be time for all those catch ups when you get a decent break, so as not to be pressured to sort it.
VERY logical diagnosis as only you can do, and the pulley will last a while, and you will HEAR it when really lets go, and teh battery goes flat for no logical reason.
The Vac advance, HA, I got trapped with those pull rod lengths a few times, and ALL were OE parts in the correct packaging etc etc.
After 55 years in Auto Spare Parts I should know better.
Thanks Grant. And you're right. I'm not worried about it. When you have a 36 year old car as a daily driver this is what you get I reckon I was having a bit too much good luck the last couple of years.
I'll set aside some time soon to roll up my sleeves again.
(Aside: I have a 1995 Ford F250 truck that I keep just for the times when, well, you need a truck. Year after year it has always idled perfectly; smoother than any of the Jags I've owned. In a wicked bit of coincidence it has now developed a high and surging idle!)
As for the balancer I reckon I'll find a used one and send it out for re-bonding. Then I'll have it on hand when the time comes to tackle the job. Actually, I have several pending non-urgent projects so I might take the car out of service for a bit and just dig in. We'll see. It kills me to not drive the car, though !
Yeah, oh man!!! All mine has done, is back out of the garage, idle in the dive. Put it back..
Making room to clean up the messy garage. and continue my planer boxes project. boxed doe, fthree of them. Second batch First was two. Paint phase begun. Barn red on the pine end caps.
Boiled linseed oil on the cedar boards... Made a lot of saw dust. it's everywhere...
Jaguar cranks immediately, idles perfectl;y. Cold at 10000, warm at 500...
Enjoyed the car a lot this weekend. Made a small road trip to visit my daughter and son-in-law for the weekend...which is like a mini-vacation for me !
Anyhow.....
Been very short on time lately but decided I had to go back to square one so I found a few minutes to pull the cap off and look at the innards of the dizzy, the vacuum advance rod, and such. Remember, my trials began when I replaced with vacuum advance. I didn't have to look very hard or long to find a problem.
What's the very first thing every V12 owner does when he removes the distributor cap? He gives to rotor a twist, releases it, and sees if it snaps back smartly. Heh heh....mine won't even turn. At all. Something is amiss with the centrifugal advance mechanism.
Maybe I dropped something in there and it jammed things up? In such as way that the timing is advanced and thus the high idle? Or....? We'll know more when I dig deeper, probably tomorrow.
Not sure this is the final answer but I'm encouraged to find a unambiguous, actual, repairable fault !
...What's the very first thing every V12 owner does when he removes the distributor cap? He gives to rotor a twist, releases it, and sees if it snaps back smartly. Heh heh......
Cheers
DD
Doug, I thought Everyone twisted the rotor first thing after pulling cap.
Dutifully adding a couple drops of oil into the distributor shaft from time-to-time doesn't do anything if the oil doesn't dribble down to the advance weights!
On disassembly I discovered the advance weights were seized. This was surprising as I DO service the distributor. I assumed that I simply waited too long between intervals but I soon found out that wasn't the problem, or at least not all of it. There was still a drop of oil visible in the oiler from the last time. Long story short, the oiler shaft was clogged. I confirmed this by filling the well will light oil and checking it a few hours later. It was still full. So, I cleaned the shaft (and everything else) with copious amounts of brake wash and refilled the well. The next day almost all the oil had dribbled down to the weights.
I don't know what the innards of the shaft looks like nor what exact path the oil takes. But, whatever it is, it can become clogged.
OK, everything cleaned and lubed and the advance weights free and smooth. That's good. The downside is that the weight were stuck in the closed position. Thus, the notion that they might be stuck partially open and thus causing my high idle went right down the drain.
That's OK. I'll keep moving on. I'm glad to have fixed something, though
Pick-up coil scuffing
As you can see in the attached picture the reluctor wheel has been scuffing the base plate of the pick-up coil. Not sure why. The picture shows the wave washer that fits between the two. Some discussions and sources mention a flat washer rather than a wave washer. I'm not sure what significance this has, if any. My assumption is that the base plate is a bit bent or (more likely) wasn't flatly seated when the pick-up coil was replaced 3-4 years ago. A bent dizzy shaft also comes to mind.
Any thoughts on this matter? The scuffing is actually very light.
I am replacing the pick-up coil anyway. Not because of the scuffing but because I'm uneasy about it being right on the cusp of no good, according to my resistance check. Spec calls for 2.4K - 4.8K ohms. Mine is right at 2.2K ! This is money I probably didn't to spend but...well....I'll feel better.
Dutifully adding a couple drops of oil into the distributor shaft from time-to-time doesn't do anything if the oil doesn't dribble down to the advance weights!
On disassembly I discovered the advance weights were seized. This was surprising as I DO service the distributor. I assumed that I simply waited too long between intervals but I soon found out that wasn't the problem, or at least not all of it. There was still a drop of oil visible in the oiler from the last time. Long story short, the oiler shaft was clogged. I confirmed this by filling the well will light oil and checking it a few hours later. It was still full. So, I cleaned the shaft (and everything else) with copious amounts of brake wash and refilled the well. The next day almost all the oil had dribbled down to the weights.
I don't know what the innards of the shaft looks like nor what exact path the oil takes. But, whatever it is, it can become clogged.
OK, everything cleaned and lubed and the advance weights free and smooth. That's good. The downside is that the weight were stuck in the closed position. Thus, the notion that they might be stuck partially open and thus causing my high idle went right down the drain.
That's OK. I'll keep moving on. I'm glad to have fixed something, though
Pick-up coil scuffing
As you can see in the attached picture the reluctor wheel has been scuffing the base plate of the pick-up coil. Not sure why. The picture shows the wave washer that fits between the two. Some discussions and sources mention a flat washer rather than a wave washer. I'm not sure what significance this has, if any. My assumption is that the base plate is a bit bent or (more likely) wasn't flatly seated when the pick-up coil was replaced 3-4 years ago. A bent dizzy shaft also comes to mind.
Any thoughts on this matter? The scuffing is actually very light.
I am replacing the pick-up coil anyway. Not because of the scuffing but because I'm uneasy about it being right on the cusp of no good, according to my resistance check. Spec calls for 2.4K - 4.8K ohms. Mine is right at 2.2K ! This is money I probably didn't to spend but...well....I'll feel better.
More updates as events unfold
Cheers
DD
Doug,
Similar irregular idle, 6 weeks into T/S'ing found "scuffing" on my pickup coil, set gap with brass feeler gauge etc. no help... turned out to be worn upper bearing...
Rgds
David
03-25-2021, 08:27 AM
