JeffTT

Ok Dicky, you have completed the full picture now, the low running temp, fuel use and soot on the rear bumper is all indictaive of a thermostat stuck open, how easy to change? see below... Mmm.. so true Richard, 49 miles according to Google maps, and dicky its not a bad job DIY but if you want it doing its a while you wait job and would include a full ConZult set up, the fuel saving after it been change will soon recoup the travel cost to Zedworld, oh and it includes tea / coffee supplied by Lynda. Cheers Jeff TT

Pasted from an old tech thread of mine in 2009 Tech tip 2 The humble engine thermostat is often overlooked when performance issues arise and can have dramatic effect in particular the twin turbo and a lesser but just as important level on the non turbo zeds The thermostat is very commonly misunderstood in how it functions and this can in turn lead to ignoring the running issues that it can directly cause. The unit works from cold by restricting the flow of water around the engine block with the exception of a small by pass hole which prevents the water pump been overloaded. A simple but effective temperature sensitive action moves the valve either open or closed according to water temperature. The restriction mentioned earlier in the water flow is designed to get the engine up to temperature quickly and efficiently and also assists the heater matrix warm up time. Once the designed engine temperature approaches the stat begins to open, this allows extra water to now flow into the block and onwards. Now this is where the story ends for many remember the common misconception that I mentioned earlier? the stat is more than just an open and shut valve it is a modulating stat which in essence the stat will close again slightly after the initial opening due to the extra movement of water through it. As this now restricts the flow again the temperature rises slightly and the stat responds by opening again, this action or “modulation” is what “regulates” the engine temperature at a mean average of around 80 deg c Now take a look at the two stats below, a used and faulty one to the left of the pic`s and a new Nissan item to the right of the pic`s. Clearly the faulty one is open and as it is at room temperature it should be closed like the new one, and what effect would this have on a zed engine? Surprisingly a LOT! The twin turbo model had built in safe guards to prevent hard boosting when the engine is cold by acting on the boost solenoid valves, now this is different to safety boost as the ignition is not effected so does not feel so obvious the temperature needs to be above 68 deg c approx. to give full boost. Now typically a stat jammed open will have the effect of reducing the engine running temp by 15 to 20 deg c which clearly will mean the engine never gets out of the cold running restriction, add to this the ecu will be fuelling accordingly to the lower temperature which is not good for mpg! Sometimes a stat although jammed will be only slightly open this then means the engine will actually hover around 70deg c, so full boost is available, until you give it some beans and the extra cooling air and water volume increase reduces the temp by a small amount that is below the full boost temperature, this can end up been a cycle of good boost ...bad boost....good boost ...bad boost..... The non turbo will of course be less effected, however an engine not running at full temperature is not running efficiently and will suffer accordingly too. So what's to do? simple change the thermostat, an easy and quick job and full stat “modulation” and engine temperature “regulating” returns and so does the happy engine performance we all crave. Jeff TT

Ahhh.. the Zedworld magic touch...... Jeff

The switch is the problem for sure, to get out the problem for now unplug the seat power plug and use a couple of jumper cables from the plug back to the seat but reverse the polarity that way forward becomes backwards, once the seat is all the way back plug the connector in correctly and now you can inch the seat forward to the correct position. Jeff TT

Yes both proven correct in their thinking, not quite the same importance when dealing with car tuning compared to the planets topography, however point taken. Jeff TT

That particular zed was running a "generic" off the shelf chip as many describe them and had no other visable means of achieving the boost level it did. At the time it was a mystery and still remains so as the mapping was basically a JWT one the same as ones fitted to hundreds of zeds. Having said that, I can see why many owners will be interested in your explaination of your take on things and the work you have done, I can also see why the established theories and guys involved at the sharp end as such will have doubts and reluctant to accept controversial things such as using standard head gaskets on big builds when for the big end of 20 years it been done a "different" way. Long term reliability of both performance mods and the integrigity of them and of the tuner is of vital importance when wanting to prove your take on things, this is I think is your weak point at the moment as a newcomer to the forum and the open zed scene. You speak of generic chips as bad things in general as they can be badly written and live mapping is the way to go, however it has not passed without notice you have a history of selling generic chips? also your very recent cessation as an ebay seller of such chips as Turbonoz was not unexpected with the bad feed back you were receiving can you see where I am coming from? for owners to trust you and even the established tuners and builders its hard when you have these conflicting issues going on, new ways of doing things is not a bad thing if they are what they say. Jeff TT

Leaving the stock boost solenoids connected will give you a reduction in boost if det occurs as well as retarting the ignition so good to keep them in place. Jeff TT

Oh yes!! Jeff

Need to know a bit more of how you have connected it all up including any rf in / outs scarts, hdmi ,digital coax or any optical cables. At a guess you may have an issue with the way it is inteconnected, some cables don`t have complete connectivity at all pins and some can be reversed if you get the wrong ones, as I said a little more info will help. Jeff TT

Zedworld wishes all customers old, present and new a Very Happy New Year.

Hi Simon, sorry I cannot help you with any help in your area, however there a few things you could check yourself if you have a litte time. So as you said it tried to start and then died may point to either a flooded engine or maybe a faulty spark amplifier (ptu). SPARK Now you need to first establish if there is a spark, remove a (any) coil pack ( 2 x 12 mm bolts) and either fit and old sparkplug or insert a small scredriver into the coil pack output and place it close to the engine metal, try turning the engine over to see if there is a spark, if there is go to the un-flood proceedure below and if not the most likely issue os with either the ptu or the cas unit and either of their connections, the cas unit ( equivelent of a distributor) is located on the front black plastic cambelt cover and is a round silver unit with a single connection plug at the 3 o clock position, make sure this is firmly connected. The ptu is located on the exact opposite side and is a silver square box with cooling fins and two cable connections, if the fault lies with a conector here it will most likely be with the left hand lower one, again clean with WD40 and a knife blade. UNFLOOD First a flooded engine is often caused by a bad connection on the temperature sensor, this is located on the alloy pipe running across the front of the engine behind the fan blade, there are two sensors there, the larger of the two with a yellow connector in is the one you need to unplug and clean the both the connector and the sensor connection with some WD40 and a knife blade. Once the connection is ok, then you need to unflood the engine, remove the fuel pump fuse located in the slim black box next to the brake master cylinder on the drivers side underbonnet area, it is actually marked on teh lid which fuse but it is easy as its the green fuse nearest the engine. With the fuse removed turn the engine over for around 5 seconds with your foot flat down on the accelerator, pause and do it again for 5 seconds and keep your foot down on the accelerator, pause once more and repeat. Now switch off the ignition and replace the fuse, now attempt a restart but this time don not have your foot on the accelerator, it will either start or cough and try to start if it does this yoiu will need to go trough the unflood proceedure again, failing this remove at least the first four spark plugs and clean and dry. There is an inbuilt self diagnostic that can give some codes but is limited on what it can tell, maybe worth doing this, see link here ( has pictures too) http://www.ttzd.com/tech/diagnostic/diagnostic.html Hope that helps and update to your progress. Jeff TT

If its a case of turning over ok but not firing I doubt an auto electrcian is what you need, someone with the correct engine diagnostics and relevant knowledge is more likely going to help. Jeff TT

News not good, despite the amount of water ingress looking small the engine is siezed tight, bent con rods are the most likely cause of this, awaiting the insurance co. answer now.:sad: Jeff TT

A nice zed arrived this evening at the workshop via the AA, the sticker on the windscreen illustrates the perils of driving in bad weather, left it unchecked as time was getting on, so will see what tomorrow brings...have a bad feeling though....shame. Jeff TT

Not surprised at all, was run by complete idiots, the business side of that magazine was terrible, when it first came out we were approached by their very persuasive sales team to sign up for a series of ads, the price was agreed as well as the time scale we wanted to spread our ads over. Our first ad was a full page as they said there was to be a Nissan 300zx feature, great ok we can do this ...big gulp £1k yes thats right a grand , two months later we are greated with a fresh copy with our spanky full page ad opposite a feature for a flipping 200sx!!!!!!!!! surfice to say it was a grand down the drain, and made worse by the high cost of the mag and the very low circulation, the next 3 ads we had arranged were added each month instead of every other month and within two days of placing the ads a factoring company sent us a demand for payment of the whole series of ads (£2,500+ vat) with 7 days or interest would be added, I rang the Ceo of the mag and was surprised to get through to him, I asked why he used a factoring company for such a young company, he said it was normal practice, I suggested the mag had cash flow issues and wanted to know if they were solvent or not and if my up front payment was safe...he said he could not answer what might happen, so thats some years ago now but I bet there are some unhappy advertisers now who will be out of pocket.....shame on them, bet the ceo is on a sunny beach somewhere though. Jeff TT

Will not cost you anything James, its a very quick job to check plug in and read the map, can do it whilst you wait. Jeff TT

One of my repair threads from some time ago, hope it helps. Jeff TT Drivers side window issues? the window power amp controller has a habit of failing leading to an intermittent or non working window, lucky it is a very easy fix and free to boot if you can use a soldering iron. The unit in question is fitted in the drivers door, it is held in place with a single 10m bolt and has one 8 way connector plugged in to it, roughly just off central towards the rear of the door. Once removed the outer case needs easing off the lower connector area, the internal part then slides out in one piece. Photo 1 shows the internal parts of the unit and the pcb its all mounted on removed from the outer case, the two relays to the left are the output up and down for the window motor and the steel busbars to the right are the connection interface to the door wiring loom and the source of the problems. Photo 2 shows the unit end up where the connector goes in and again the source of most issues the unit suffers from. Photo 3 shows the rear of the pcb and the area in red is where the connector busbars are soldered to, not easy to see the problem yet. Photo 4 shows the problem in clearer detail, the pin solder has failed and this is the cause of the intermittent or no connection and the failed window operation. Photo 5 shows the method of repair, by applying a soldering iron to the effect area the solder will reflow and make a new connection. Photo 6 shows the final result, a nice solid connection that will get that window operating again, just put the unit back together and refit to the door. Happy fixing :D Jeff TT

here you go. Yours Jeff TT

Was not directed to yourself. Jeff TT

Ok just to clear this up for the unbelievers we have hundreds, maybe a couple of thousand original eprom ( chips) we have removed when socketing and fitting reprogrammed units, a good 30% appear to be the original eprom removed, reprogramed and refitted, most of these are from imports so its a good chance its from a particular tuner there that was doing it. The Japanese authorities have in the past ( mid 90`s ) came down hard on road cars been tuned and anyway to disguise the upgrades they did it in fact also many reprogramed eproms that are fitted to imports still had / have the 110mph speed limit in place again to keep it looking standard. Vern, if you want to send the ecu to us we can check it and return it to you the same day with full breakdown of the mapping. Jeff TT

The screws can be a real issue due to thread lock and soft headed screws, the trick is to tighten them first to crack the thread lock. Also its very possible the ecu is still upgraded but the eprom was soldered back in rather than in a socket, only way to check it really is via a ConZult. Jeff TT

!!!!!!!!!!!!!! Nissan UK are total robbers, £86 for a bit of plastic! the same part for a BMW M5 is less than £30! I know had to buy one last year. Jeff TT

That is well spooky!!!!!!!! Jeff TT

When you say No 4 plug wa out do you mean the actual spark plug or the coil pack / connector on top of the plug? two very different things. Jeff TT

Hiya Anthony So sorry to see this I don't know how i would feel about this if it happened to cassie, the owner should at least be made to pay something, We both hope Primrose will be okay. lynda zedworld.