MattDaKav

Wow. Top stuff! Great to see another one saved!

Hi all, I've still been enjoying the Z, even with the occasional cloud of smoke. However, the rev limiter is set pretty low, I guess as part of the safe map to try to protect the (potentially) damaged engine... The spark cut limiter fouls up the plugs. I have been running the NGK PFR6B-11C gapped to 0.035" ... do you think that I could get away with using a slightly hotter plug at 1 bar of boost? I see that the PFR5B-11B was the stock plug before this was superseded to the 6. Thanks.

Quick update here... I've been super busy and haven't done any more investigation into the cause of the problem, but I have been using the car occasionally with no issues other than the smoke itself. I went for a proper two hour hoon last week, the most aggressively I've driven it, and it didn't miss a beat.

Nice one, thank you.

I found your old thread about this: https://www.300zx.co.uk/forums/showthread.php?181790-I-am-losing-it-need-advice It does sound very similar although you mention that it only happened when warm, pretty sure mine is initial driving when cold too... if anything, it seems to smoke less as it warms. I'd be interested to know if the crown(s) showed any damage as I might be able to see something similar when I put the endoscope down the plug holes. Cheers.

Cracked crown? Do you know what caused the crack on your engine?

:excl: Uh oh!

Guys, I appreciate the input from all. I didn't mean to cause any conflict... just trying to figure out how to get this Z healthy again.

Thanks

Sorry, just so that I'm clear, do you mean that the timing would've damaged the pistons because they may have hit a valve? ... or some other reason?

Thank you. I have just bought myself a cheapo endoscope so I may discover something over the weekend.

Yeah, but then I wouldn't have ended up with a Z32... so... silver lining (for me... kind of). If it needs a rebuild, it is what it is. It's not my daily so no biggie... I'm just hoping it turns out to be something more easily resolved, even if that's a long shot.

Hi Mike, thanks for the further details... although my understanding of the mapping process is limited, it may help me figure out what the current state of things is. Cheers. Any thoughts on what damage having the timing off that much may have caused?

Johnyboy, Jimmer, I like your optimism! Although if the cause of the smoke is now left over oil in the plenum or in the exhaust, I would've thought that it would be more constant (once warm), rather than coming on after the intake has been in vacuum as before when the suspect was oil being sucked up the PCV pipes... I would have expected a change. I will certainly give her a spirited drive and will report back. Thanks all.

I haven't driven it hard and only went for a 20 min drive. There was certainly oil in the plenum beforehand. I will take her out for a longer drive on Thursday night.

Thanks all. The PVCs were new but my theory was that they were picking up the over filled oil, like the sloshing of oil on track reportedly does. I deleted them anyway as I hate the idea of PCV systems.

All VG powered too. :punk: I have a 928 that I will be selling shortly and then I'll have more time to spend on the Zs.

It's running an AEM EMS 1 and the MAF is redundant now so BOVs should be ok? I haven't got to plugging in a lap top to have a look around yet.

Z32 currently looks like this: Z31 currently looks like this (with bonus Elgrand):

Hi all, I'm a longterm Z31 owner (still have one) and have also had a few other Japanese cars over the years, amongst German stuff and classic British stuff... also into bikes. The Z32 is now retro enough to tickle my fancy and is a JDM legend in my opinion... so I picked up a semi broken manual TT to play with: https://www.300zx.co.uk/forums/showthread.php?190299-Risk-it-for-a-biscuit-bought-a-potentially-broken-Z Although it's broken, I cant help myself and have started doing the fun stuff; wheels, spoiler, steering wheel, etc I'm in Weybridge, Surrey, if anyone's about that way. ??

Indeed. Compression and leak-down tests are on the to-do list.

Thanks Gaz. I've spoken to Mike via FB and he has been very helpful, although I don't think that he ever got to see the car again after finishing the build.

Hi all, I bought a manual TT that had recently had an engine rebuild but still had some problems. I took a chance on it... this is generally my preferred approach, it's more fun... kind of. When I picked up the car, I discovered that it smokes on overrun; decent plumes after engine braking at low speeds, then when the throttle is reapplied or if the engine settles at idle (typically when pulling up to a junction or slowing and accelerating between speed humps). No smoke when accelerating or at start up / idle. I have been doing a lot of googling and reading a lot of old forum threads about these symptoms, but none of them finished with a conclusive result. I will make sure that this thread has a conclusion even if it takes a while to figure out. Advertised spec: Engine rebuilt by Outlaw Customs Wiseco forged pistons Eagle rods AEM series 1 ecu 615cc Nismo injectors NA rear diff and hicas deleted Rebuilt turbos Stainless steel custom exhaust with H pipe and Greddy back boxes HKS blow off valves Currently running 380hp, mapped by DWR Performance Culprit #1 - PCV I noticed that the car had too much oil in it, and thought that maybe the PCV pipes are pulling oil up into the intake plenum during vacuum, which would then get burned off as the engine idled or accelerated. I looked into the balance tube holes and there is oil in the plenum. I then did an oil change and deleted the PCVs for good measure (into a catch can), the pipes were full of oil! I also swapped the spark plugs from Iridium BKR7EIX (which sit too far in the head) to NGK PFR6B11C gapped to 0.035. I have only driven the car around five miles since, at first it seemed much better but the smoke problem returned. Perhaps I need to drive it a bit more. Should I also reroute the breathers at the front of the engine? My next potential culprits are: Culprit #2 - turbo seals Culprit #3 - valve seals Culprit #4 - piston rings ... anyone want to add to the list of possible culprits? Cheers.