RobH

Thanks guys, I'll check it out tomorrow. Typical - I can take out and replce the engine, gearbox etc but don't have a clue when a fuse blows ;-) H

Hi guys, This wouldn't normally be a problem but I'm 200 miles from home doing some exams and my lights appear to have packed in. I can still get high beam but no tail lights (brake lights still work tho) and no low beam. I have to assume it's this fkn weather, it was well covered in snow last night and badly iced up this morning, presumably a short somewhere. I only have limited tools with me and very little time to spare at present, I'm not looking forward to a drive home with only high beam in this weather! Just wondered if anyone has had the same problem and whether there is a known prob/easy fix... Tia! RobH

Very interesting (no, really!) I guess I'm going to have to think some more. Cheers H

Ok, thanks guys - hats off to ya ;-) As has been pointed out to me elsewhere, I'm thinking of an old system of simultaneous injection rather than sequential, I assumed our old motors were pre sequential... Cheers H

Hi All, I suspect I won't get an answer to this now Duffer has been banned (what a sad loss to this site, anyone know if he's haunting an alternative site?) Anyway, I'm hoping someone can offer a definitive answer/confirmation... I've had some injector problems which have lead me to consider the fuel system as a whole. I believe that the injectors have a common power/signal supply and all pulse simultaneously, I also suspect that if a single injector goes down or is unplugged that the rest will receive a larger signal and inject more fuel leading to a rich mixture on the 'good' cylinders and unburnt fuel. This would explain a lot, can anyone confirm that this indeed correct? Thanks in advance. RobH

you can get a 1/2" square drive 900mm extension, think mine was Laser, - makes the top bell housing bolts really easy! Wish I'd bought mine before taking the box out :-\

I think the logic is that a 'bad' tank of fuel will cause det at low revs and adjust the ECU to run a knock map (retarded ignition and safety boost) instead of a standard map. Engine noise above 3K would make detonation difficult to identify by the crummy Z knock sensor, I think there are aftermarket sensors which work better at higher revs.

check the pressure with a gauge teed in between the fuel filter and metal pipe attached to the top of the plenum, think it's supposed to be 42 PSI at idle but get confirmation of this..

Z32, do you mean extra boost needs more fuel rather than vice versa? If you compare to SMW's AFR plot on the previous page, James' looks very rich, I wouldn't expect lean AFR to be the issue. Was it detonating when the dyno run was made? Have you confirmed all injector connectors are good? You may have one dropping out occasionally. If the problem is limited to 1 cyl then the plug from that cyl will look different, check for a clean, glazed appearance of the firing end and possibly tiny 'blisters' on the ceramic insulator - that should at least narrow it down to the offending cylinder. Cheers H

Finally got the old heap back on the road but the MOT tester said there was an issue with emissions - rich at idle and lots of hydrocarbons, he let it go anyway as he said it wasn't a prob for a jap import and especially at that age. He did say it had a prob of some kind though to make emissions that bad. I've been messing about with it this evening and found a couple of things which I'm not sure about, the AAC is reading partially open all the time and varies with RPM - is this correct? Secondly, the MAF is usually around 1.26V at idle but occasionally dropping to zero volts. I'm pretty sure the MAF is ok as the car still revs ok, is an occasional zero reading to be expected? Last thing, I logged the boost curve as I suspect I may still have a leak somewhere, I've not attempted 1 bar yet as I need to set the car up properly first. For a constant throttle setting the boost ramps up ok, levels off and then begins to drop gradually. Is this normal behaviour? If so I can compensate for it with an increasing duty cycle v RPM, or is it indicative of a boost leak? Cheers RobH

I think it was 3 months in the end (!) I wasn't in any hurry though as the engine was out for most of that time. According to the retailer Autobahn hadn't had a production run for some time and hence I had to wait until there was a kit available. If they have one in stock the turnaround would be quick, I'm sure... H

Why not buy from Flat4online? I did, £200 delivered :-) from a UK supplier, took an age to arrive though. I was reasonably impressed with the quality but it is quite difficult to get a good seal on all the pipes and hoses. I was sure mine was fitted well but found some small leaks around some of the joins after attacking it with a squirty bottle of diluted washing up liquid... Seems to do the job but I've only just got my car back on the road and haven't hit 1 bar yet... Cheers H

Maybe check the stock boost sensor hose and connections (rear drivers side of engine bay). I would say the boost sensor hose was off or damaged but having the boost drop again when the engine goes off is illogical... H

You prob need to get the front bumper off to have a proper look. The inner tube will be a bit strong to give you a good indication, a surgical glove or condom :P will give you a better indication as they will actually inflate when the leak(s) have been bypassed... Other prime failure locations are the large, flexible plastic pipes that run from the intake 'T' to the turbo compressor intake hardpipe, very difficult to see without removing some other stuff, may have come adrift at the join or can split (I had a split one a few years ago). It's an unfortunate fact that to eliminate a boost leak you have to make yourself familiar with the whole intake circuit and get an idea of the route that incoming air takes through the turbo compressors, intercoolers and ultimately to the throttle bodies. It's made particularly difficult on the Z32 thanks to the lack of space in the engine bay but you will feel a better person for understanding how the system works and it will make future investigation much easier. Cheers H

You won't be able to pressurise the system if the leak is anything bigger than one of the small hoses (and it sounds like it is). Best you can do is break down the intake into smaller sections (start off by taking each side in turn and checking up to the intake pape which runs to the throttle body), gradually add new sections as you prove each section as 'good'. I use a surgical glove over the end of the hoses with an elastic band to hold it secure, if it inflates to the point of expanding then you know it's ok. You may also need to plug up the front PCV's to keep some pressure in... FWIW I'd be tempted to check all your large IC hoses

Vern, if you mean it's as though the engine is 'revving itself' every time the revs drop then I would expect a BIG boost leak - probably around the intercooler hoses. I had the same thing, pretty sure that's what it was (although I also corrected some other stuff at the same time) By disconnecting the MAF it will go into limp mode, will probably run nicely at idle but will not rev much past 2000, if it feels bad in a different way with the MAF disconnected then this isn't your problem. Mine would rev higher (though very badly) with the MAF connected, revs hit a 'brick wall' with MAF disconnected. Might also be worth checking the vent from the carbon can is not blocked, could have been that that was my issue - I can't be sure without blocking it up again! HTH H

Use the standard NGK's unless you've got big mods. Part is PFR6B-11C, these are pre gapped to 1.1mm (11 at the end of the code). A lot use PFR6B-11B for minor mods, slightly longer shroud/less projection, this is not a UK part and is no longer in production, you'll need to find someone who imports these from a stockpile in Japan or the USA if you want to go that way...It's a bit of a myth that these run colder, they simply afford more protection to the firing end and have a shorter ground electrode (hence less chance of det.) - If they ran colder they would be a '7' ;-) Wouldn't bother with plugs from the 'tuning companies' (Blitz, Apexi, HKS, Greddy etc) they're made by NGK or Denso anyway, you pay extra for the badge... Cheers H!

Think I've sorted it, latest changes are relocating the engine block ground strap, refitting my bigger injectors, new plugs (again!!), put the Nistune daughterboard back in and programmed with a 550cc image, had to fiddle with one of the injector connector terminals which was being pushed out of its housing when pushing it onto the injector. Took it for a spin last night and got half a bar (that's all I'd set the AVCr for). Sounds good and idles quite nicely. The downside was that a fkin RX7 pulled up behind me at the lights and was able to get past me due to my low boost setting :-( BAH! Bet he thinks his car is faster than a Z now - fker! John, am I right in thinking I shouldn't be dicking about with the injection multiplier and latency until I've got a wideband O2 sensor installed? It's awfully tempting ;-) Cheers H

Hi guys, It appears that I wired the AVC-r's optional injector monitoring connector into the RPM connection (this allows self learning mode) - it was in the dim distant past so I had forgotten. The downside to this option is that the injector duty cycle reads a load of b*ll*x. I made some other changes yesterday - including a gaping boost leak (tut!) and opening the fuel tank vent hose (previously connected to the carbon can which has been binned) - the original metal tube it connected to was blocked solid!! The carbon can was split hence venting was not a problem when it was in use ;-) It's still running like a pig and sounds pretty awful but the black smoke has gone and I have been able to hit half a bar! Not bad considering it only seems to be firing on 4 or less most of the time! Compression test and new plugs today, new injector and coil pack connectors are in the post (they're all fkd)....might be running again by next summer... Cheers H

Double check the timing, make sure it's properly warmed up when checking and that temp sensor is working correctly. If you use the inductive loop for checking timing try the alternative method with a length of HT cable and plug cap between direct fire coil (incorrectly referred to as a 'coil pack' ;-) ) and plug terminal. Both methods have been reported as giving 'odd' results so trying both should rule out any inaccuracy... Has your det sensor been bypassed? Have you checked all injectors and CAS are working reliably? Fuel pressure also looks like a good bet...filter replaced? What plugs are you using? You should be on a colder grade and pref with smaller preset gap (= shorter ground electrode) if making over 400BHP, 2 grades colder if making 500BHP+, downside being idle may not be as smooth and fouling may occur in town traffic. Cheers H

Yep, it was ;-) TBH I think it's well on the road to recovery, just took it for a spin and apart from dreadful misfiring/backfiring/general roughness and an assortment of extremely embarrassing noises I was reasonably happy. I know I have some dubious injector connectors and my plugs are badly fouled, once I've replaced these I'm expecting an improvement... Cheers H

Cheers, will have to pull the cover off and have a look I s'pose :-(

Hi guys, Making some progress with my 'dodgy motor'. I've been trying to pressurise the system without much success, I've resorted to breaking the system into sections and testing one section at a time. Found some big and small leaks but when attempting the entire system it won't seem to hold anything. I'm only using a cheapo air compressor which is pretty slow to inflate a bike tyre. It seems all my pressure is escaping through the front PCV hoses - presumably into the crankcase? The hoses appear to have a baffle and a wire filter inside, is there a particular orientation for fitting these? (i.e. baffle or wire filter on engine side). The system can be pressurised by blocking these hoses. If I had cr*ppy compression (i.e. stuck valves) would it be impossible to pressurise the system? Cheers RobH

Ok, bit of progress from me, one of the intercooler pipes was hanging off and there were other smaller leaks around some other IC hoses. Interestingly I checked the metal vent pipe that the fuel tank breather runs to (the only connection left after bypassing the carbon can), it was blocked solid and leads me to think this may have caused an issue with over pressurising the tank and possibly leading to increased fuel delivery. I've removed the pipe now so it is again venting to atmosphere. It must have been like this for a while but my carbon can had split (bottom had come off) so this was probably venting any excess pressure previously. Car is running much better but I haven't had chance to drive it yet. Sounds like you have other issues with your ECU now Trond but might be worth checking the vent as mentioned and IC hoses for your original over fuelling prob. RobH

I'm wondering if it has anything to do with the egr/aiv/prvr (carbon can?) delete. I deleted the same parts and have almost exactly the same symptoms. Are there any other issues to be taken into account when deleting exhaust gas control stuff? Perhaps a fuse to pull or something still connected which shouldn't be??? Maybe a vacuum line been removed which shouldn't have been or one disconnected which needs reconnecting to the intake? Oh, and one more thing, the 90% injector duty at idle, a friend of mine also made the observation that this was working in reverse, if that is the case wouldn't it be reading 100% with ignition on and engine not running (!?) - mine reads 0%.