Resistor Spark Plugs

iis_iis

iis_iis

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NSW
..me again, been chasing a Toyota 2004 Estima "CVT" transmission problem only at 2000rpm on the road, local service workshop were only making things worse, and not worse in the sense of actually working on the problems, ie making something worse usually means your onto the fault, just the wrong direction. Various tradesman were floundering.

Had ( bought the problem vehicle from a lady owner tired of repair bills that were way to high ), taken me near two weeks to undo the incorrect misleading "repairs" and then concentrate on the actual fault. Easy things first brought marginal improvement, though not convincing. Ordered a set of new plugs, NGK resistor type, grade 6. Well well... its a new motor and no transmission jerking at 2000rpm. Here is the cause, only a 500V megger though you can see it jumps all over the place for a conductivity test, for those not familiar with a hand crank megger, the actual resistance was moving from 1 to 50Meg Ohms a long way from nominal 5K Ohms.

While we may now be using internal resistor plugs, we may well find a new problem to deal with, not so easy to diagnose in certain types of engines.

3 out of the 4 plugs were high impedance centre electrode. Movie to witness. j
 

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Interesting. Something to bear in mind. In your opinion were they genuine NGK's fitted ?
OE Toyota here in NZ seems to be ND. They're the agents here too.
 
Many are the not well knowns Greg, will work through what can be verified. In this case these plugs came from a 2ZA-FE 2.4L 4 cylinder motor well known around the globe. COP ignition system, failed cam cover ( rocker box..oz description ) gasket and cover, ie the plugs were drowned in engine oil for some time. To my eye, genuine high mileage plugs removed, genuine installed.

Clean oil does not conduct electrically, contaminated oil can. This motor started and idled, free rev unloaded. Was only in overdrive at 2000rpm ( yes i know a bit low to engage overdrive ) that this jerking started to become noticeable or worse.

There are many rectifications i performed, concentrating on the CVT in the main. Did all the usual injector clean, et al. j.
 
John, a little confused here. Were the plugs in the engine bad or the new ones you just bought?

Also, I was going to say you are living in the past with your had crank megger but I remembered my megger is a vacuum tube one so yours is even newer than mine.
 
New NGK plugs good, original ( came fitted to the motor when i bought the van ) 3 out of the fitted 4 NGK plugs failing in series resistance Bruce, j
 
You're a braver man than me John. Taking on a dodgy CVT transmission.

I was talking to a bloke a year or two ago who had a Nissan Murano with CVT in which the transmission failed at some fairly low mileage, but the car was over 5 years old so out of warranty. He was told by a service agent that the CVT is not repairable. He was quoted something over $3000 for a new transmission, plus the labour to install it. Last I heard he was looking at putting an ordinary automatic transmission in it (out of a Nissan Maxima I think) but there were some issues with the Murano's ECU not working with the Maxima's auto box. I dunno what the outcome was. I reckon if it was mine, it probably would have accidently caught fire and ended up as an insurance claim.

I'm an old fart. As far as I'm concerned, even a common as muck automatic transmission is some new-fangled product of the Devil. Give me a dumb old manual gearbox with a stick I can push around to find the different gear ratios. :)
 
As you say Cam, CVT was not on the local commercial workshop radar, rightly or wrongly, prices have changed, rectifying a CVT even the Toyota ( sub company of theirs makes them ) will run you to $4.5K now days, plus or minus remove motor and transmission. This model van comes in a 4 or 5 speed manual box in Japan, though only offered in Australia as 4 or 5 speed auto. Was hoping to find a manual gearbox to try and fit.

Again your on the money, Cam, its the tie up between engine ECU and auto transmission that brings issues for modifying factory setups. Did some solder reflow work on the combined ECU/Transmission controller pcb, which did result in a changed operation ( for the better ) of the CVT and then i turned my attention to the motor proper. Easy things first, took 2 weeks for new plugs to arrive, when fitted the Engine CVT were matching much improved. Disable the overdrive for town work, as 3 speed is adequate and keeps the 280K kms motor from lugging.

Must say though the CVT is overall a good performer for 280K kms, if the original, and the previous owner bought it as a jap import. Some 10 years ago. While there are wins, time will be the arbiter as to what has been rectified in my 3 week ownership. Already removed all the rear seats ( 6 person ) to make way for gig equipment transport.

Nice to see you here Cam, you had the touch of the "CVT" about you, shifting not as should, ECU brain required a bit of reflow work... hope your suspension does not pack it in... keep moving, else rust will get you, j
 
I took my mitsi 3.5 to our mechanic with a gearbox problem once, I’d already decided it was terminal, he took it for a drive and decided it was just a miss. Looked under the bonnet and found oil from a gympie rocker cover gasket running down on a plug 👍
Good mechanic that, shame the bugger’s retired!
 
Reminds of the saying “ most carburettor faults are the ignition and most ignition faults are down to the carburettor! “
I once fixed an XT600 that was a twat to start-been to every shop, carb stripped, valve clearance, air leaks blah , blah. It had the wrong short reach plug fitted and everyone just kept fitting like for like instead of checking for correct plug.
 
Nissan CVTs are particularly bad. Here in North America Nissan is coughing up over $275 million following a class action lawsuit that's forced them to extend warranties and provide free replacement and even compensate owners who had other shops replace failed CVTs.
 
S
I retired from 40 ish yrs. as a Honda tech and have no love for CVT transmissions. Low speed shudders were common and often caused by neglecting the oil change interval and sloughed off crap embedding itself in the start clutch. To rectify it we were told to "burnish the clutch" by changing the oil when warm and then holding the brake on and flooring the fucker for about 30 sec. holding the revs to about 2500- 3000 for 15 sec. then idling in neutral for 30sec. then doing the same in reverse,15 sec. @ 2500-3k. rinse/repeat about 10 times and change the oil again. Then do it all over again, change the oil again and drive it to see if it was better. Usually it was, 12qts. later. Also if your engine has an EGR valve check if that is leaking [soot/carbon on the pintle] So glad I've retired!
 
Transmission, Continuously Variable Transmission, abstraction of an Auto transmission, many have pusher belts rather than normal pull belts...j
 
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