RobH

Most of the problems I've heard of with use of Iridium plugs are due to using the wrong type. All common 300ZX (Z32) use an ISO standard plug - I know some people have fitted JIS standard plugs - these are longer, Z coil packs weren't designed for use with JIS types. It's not usually a problem where simple plug caps are used but where coil packs are on top of the plugs you can see where it may be a problem. Quite a lot of folks seem to buy from US suppliers on Ebay and the like (good luck to you) - IMHO the US guys don't give a monkey if they sell you the wrong type. They may believe they've sold you the correct plugs but don't forget they're selling to the US market with different driving styles/fuel grades and hence often a different required heat range. People are also often unsure about selecting the correct heat range when going from say NGK to Denso. More of an issue is fitting an ISO plug to a JIS designed coilpack (as with all turbo Skylines and I suspect earlier model 200SX - never seen under the bonnet). There may not be sufficient contact between coil pack and plug terminal therefore creating an auxiliary gap which may be a little too much under high load. John, ZFR7F-11 is an unusual choice, being extra projected - put's the fragile bits right in the firing line. It's usual to go less projected when a colder plug is needed. BKR7E-11 would be a closer copper replacement and even cheaper (I'm not endorsing this though!) Mr Duff (hi!), valid point, but relatively speaking you're looking for the most efficient spark you can get. If you could induce a more perfect spark then you would be getting better combustion - compared to a platinum plug there is a difference in power produced. Doesn't every engine component lose you power if you look at it that way?? I have no axe to grind, I'm just as happy selling Platinum as Iridium :-) - best thing about Iridium being the availability of colder heat ranges for tuned engines. Didn't mean to give a lecture but there you go - sorry! RobH

You're more likely to get detonation with over advanced ignition timing (15+ degrees) - you shouldn't be getting any at 10 degrees advance (!?). Advancing to 15 may make the problem worse if it is an ignition timing problem. If you're at 10 degrees you should be quite down on power. One thing though, I read somewhere that if your timing is retarded your engine will run hotter so if you've got a cooling problem, the retarded ign may be making things worse. RobH

Alright Mr D?! I still have your cam belt tensioners!! People seem to report mixed results using the PTU loop - maybe it depends how good your timing light is... Ciao!

You'll need to get a strobe timing gun to measure it safely. You'll also need a piece of old HT lead and spark plug connector to get a good reading from number 1 cylinder - the loop on the PTU is pretty poor for taking the signal. If you're a gambler you could just mark up the CAS, slacken off the bolts and rotate the CAS clockwise a couple of mm at a time, checking for improvement every time you adjust (can't believe I've even written that - very bad idea!!). My guess is that my CAS partially failed which caused the shift from 15 degrees to 30 degrees base setting (this is a reference setting that the PTU does its sums from - not the actual ignition timing advance setting). HTH

As Bilky says, standard plugs are PFR6B-11C. If you've got lots of mods then a colder NGK '7' or Denso '22' may help defend against detonation. Take another loook at the plugs, they'll probably have tiny black blisters that look like specks of dust on them - this is evidence of detonation. Clean white plugs are evidence of running a bit hot - should be tan or light grey for correct running. Check the ignition timing base setting, advanced ignition has to be number 1 cause of detonation. Mine slipped 15 degrees with no explaination and similar results to those you describe. HTH! RobH

Mac - I can only comment on my own personal experience. I'm just happier with a manual and much prefer my car that way. Also used to lose the back end regularly in the wet and found it *very* difficult to get back with auto box and no traction control - just dab the clutch with the manual and all is well. ;-) RobH

Have to agree with MarkyB, I was kidding myself that I was happy with it being Auto and think it's almost twice the car with a manual box... If you are going to replace with another auto don't waste your time/money with a replacement standard that may well die again inside of 2 years - like the auto boys say, fast road rebuild is the way to go! Cheers! RobH

Oh and if you want to be really pedantic it's an ISO height. Ciao!

14mm x 19mm x 16mm hex :-D

Rich, where did you take it for the MOT?? There's some complete cretins doing MOT's in Chester - real jobsworths. There's a couple of backstreet places under the arches behind the racecourse that seem like good geezers, got my jap done there no probs... Cheers! RobH

Check your base ignition timing!! My guess is it'll be advanced by 10 degrees or more too much ;-) This has happened to me and others for no apparent reason. Maybe CAS on its way out. RobH

Hi Ant, The spark plugs section has gone from the traders forums but still very much in busines. You can still access the 'special offers' page at http://www.sparkplugs.co.uk/pages/specials/300zx.htm . No stock of BKR7EIX-11 at the moment but everything else is available. Many standard Z owners find BKR6EIX-11 work well (better in my opinion) and are cheaper than the standard PFR6B-11C. If you've done the standard mods (chip, exhaust, boost and intake) then Denso IK22 Iridium might be worth considering, one grade colder than standard - these are the same plugs that HKS market for extra cash. HTH! RobH

Hi guys, thanks for the replies, it's actually that the clutch doesn't operate until the pedal's an inch closer to the floor than it used to be. We had a proper look at it today and it looks like a leaky slave cylinder. Ho hum. RobH

Hi all, Bit of an odd clutch problem. The point where the clutch bites moved overnight - so much so that it was very difficult to get the car into 1st gear now and all other gears are a bit of an effort. Checked the fluid reservoir which was below the minimum, topped it up, bled the circuit (which seemed to be ok) and no difference. I've adjusted the pedal to maximum now so the car is driveable. S'pose I must have a leak with the reservoir being empty but it's not gone down since I topped it up last.... Any ideas?? Cheers! RobH

'k - thanks guys!

Hi All, Got a bit of a smokey problem so want to change the PCVs before chucking all the money I don't have at new turbos. My Nissan dealer is quoting a stupid price for the valves/hoses so I was thinking of buying from Courtesy. Can anyone tell me if they're sided in any way?? i.e. will US valves and hoses be ok for a Jap/UK car?? Anyone else interested in splitting the postage on a set of these? Cheers! RobH

You have an aftermarket ECU - remapped for increased performance (generally known as 'chipped') - better tell your insurers though as you ain't covered til you declare it!! The wooden panel is standard although a little odd...

Erm...Ben's car is living proof that an NA box can be grafted into a TT. Ben has TT flywheel and an uprated TT clutch I believe. I think he had to grind something down a very small amount on the bell housing. Having said that, he does have some starter motor/ring gear probs, supposedly due to a broken bolt on the starter housing though if memory serves... Cheers! RobH

Not sure about the dimensions but the TT clutch is a more heavyweight item. The TT uses a vacuum servo to assist clutch operation as without it it would be very heavy to use...AFAIK the NA doesn't use the servo (also known as clutch booster) so you wouldn't want to use it for commuting. Not sure if Ben's still got my standard 2nd hand TT clutch...never fitted it, opting for the RPS upgrade from Smithy. I'll check with Ben if you're interested... Cheers!

Belts should contract in cold weather - but then I guess so should the pulleys keeping things more or less even. More relevant is the amount of drain on the battery that cold starting causes and also the lower performance of a battery in cold weather - the alternator is under increased load for a short while to top the battery up after startup. Belts are bound to stretch/wear a bit over time. Cheers!

Easy enough job to adjust the tension but you do have to go at it from below....

Hi, I had the same problem. Probably due to a sticky shift solenoid. I was told it would need a new/recon box so I had it converted to manual. If I thrashed the nuts off it in 2nd it would occasionally change up. You could try checking some of the sensors are working correctly - TPS is known to cause dodgy gear changing, also speed sensor. If it's had a km/mph conversion check all the connections are good and your speedo is displaying correctly. RobH

Ben Wagg's done mine and his so he knows what the job involves. I think ChrisC did his own, Luke at the Z centre has also done some. Try to find a complete car (with good box!) that's being broken and get all the donor parts from one vehicle. Parts have to be carefully removed (not cut) - especially hoses, wiring, switches etc as they are seemingly less important but make a massive difference to cost if you need to buy them new to finish the job - a real problem to find some bits second hand if you can't get them all at the same time. You're prob looking at £1K if you can DIY with 2nd hand parts. HTH RobH

Maybe the battery starting to die...will cause extra load to be placed on the alternator, especially on a cold start after it's been sat draining all night. Worth checking but your alternator belt must be a bit slack anyway to slip under high alternator load. I'm assuming it's the alt belt ;) Cheers!

If it's a standard vehicle then try Carole Nash's classic policy, modded and or an import try A-Plan. I think a lot of people on here may be happily ignoring the fact that they aren't actually insured for the car they're driving - it's fine if you want to show the law that you're insured but a useless piece of paper if you want to make a claim. Insurance companies don't like paying out if they can find a reason not to... To clarify, I pay Cheers!