300zx 1988 Z31 ignition parts needed

[scb1957]

Hi , I am after the power transistor that is located above the coil pack on my 300zx. I believe that the early Skyline and early Z32 use the same coil pack as mine, but whether they use the same power transistor as the switcher for the coil, I'm not sure. The car is dead in the water without this transistor, so any help would be appreciated in locating one of these. I can be contacted on 07989 512720 and my email is info@scbsystems.com.
Thanks in anticipation. Steve.

 

[STEVE BURNS]

Hi Have you tried Mr.F aka Mike Feeney at MJP Autos
also big thumbs for subscribing to the club

 

[jonbills]

Does it look like this Steve?
https://www.rockauto.com/en/moreinfo.php?pk=1187367&cc=1209620&jsn=367
I'm not very knowledgeable on Z31 stuff - I was just reading this thread https://www.zcar.com/forum/10-70-83-tech-discussion-forum/93038-secret-power-transistor.html and was wondering if the problem was availability or just price?

or have I got the wrong end of the stick?

 

[scb1957]

Hi Steve, that's it! Nice one.....a bit pricey at £189, but if that's what it takes. Thanks a lot

 

[scb1957]

Looking at the link you sent me, it appears that "any power transistor" should do the job, although I have just put a 30a NPN TO 3 transistor in place, and instead of the car running extremely rough, it now doesn't fire at all. Back to the drawing board.

 

[jonbills]

Yes I think he says it's not really a transistor but a hybrid device, but any such hybrid device (called a transistor on the cars) should do.

 

[scb1957]

Hi Steve, can you give me any more contact details for Mike Feeney.

 

[STEVE BURNS]

Hi Steve try here
https://zclub.net/community/index.php?threads/re-change-of-address.19949/

 

[scb1957]

Hi Steve, thanks for the contact details for Mike. He has made some enquiries, and it appears that Nissan UK no longer supply the part. There is a part on the American scene that doesn't match up with our part number at a cost of nearly £270, and it may not work. That is a no brainer, even if it did work, so I am going to trawl the internet for a power transistor that should fire under the same conditions as the original one. I can buy 80 power transistors for the price of one Nissan one.

 

[jonbills]

How about this £42+ delivery?
https://www.rockauto.com/en/moreinfo.php?pk=1190912&cc=1210600&jsn=363

and you need this too:
http://www.xenonzcar.com/z31/prw2.html

I think I must fancy a Z31

 

[scb1957]

Hi jonbills, just ordered one and should be here in a couple of weeks. Thanks for the link and let you know how I get on. Cheers Steve.
P.S Just been speaking to my electronics genius, and he tells me that a Darlington Transistor is basically 2 in one. It has a miniscule current requirement to trigger, but can handle massive output current. Sounds like what I need, but going to try this device first.

 

[scb1957]

Hi , device arrived from America, and once installed, I now have my spark back, but I am now back to square 1. The car may or may not start, but either way , It won't fire on all six. It pops and bangs with the help of a large throttle input, and on the odd occasion, actually fires on all 6 at around 4000rpm, but only momentarily, after which, it splutters and then dies. Now going for fuel problem, rather than electrical. It sounds to me like its a starvation problem. Answers on a postcard please.....

 

[jonbills]

At least its a step forward. What's the previous history? When did it last run well and what happened after that?

The symptoms sound like either very lean fuel mixture or could be wrong firing order.

 

[scb1957]

Hi, I did a lot of work on the paintwork over the decent summer period, and at the end of July, took it for an MOT. When attempting to leave the MOT garage, the engine started to cough and splutter when giving the engine some throttle, but still ticked over. I moved the car forward, and with the car pointing now downhill, the fault cleared. I got it home and thought nothing of the problem as the fuel level was low. A week later I took the car out, but within 500 yards, the fault re-appeared and the car almost cut out, but sprang back to life, so I spun round and got it home. The problem magnified, to the point that the car will not start, without coaxing it with the throttle, but it kicks up on less than 6 cylinders, popping and banging through the air filter, then the engine dies. I attempt to start it again, and it may then tick over for 30 seconds, then dies again, or it may not start at all. Can't tell you much else really. I took the fuel pipe off the top of the fuel filter, and got covered in petrol, so there's plenty of pressure

 

[jonbills]

I've had similar on very old fuel - how old is the contents of your tank?

I wish I knew more about z31s.
Maybe go back. To basics, check sparks are in the right order, that timing is roughly right, that injectors are all firing cleanly etc and see what's what.

 

[scb1957]

I have replaced the HT leads, the ignition module and the dizzy cap. The timing can't have moved, so that's why I am going for a fuel problem. I start the car regularly when its not being used, and until this problem sprang up, it started in a nanosecond. I can't go with fuel contamination, because it was fine driving to the MOT station.

 

[scb1957]

Hi, the story now changes. I can now start the car and it runs ok ish until it warms up. Then it starts to misfire and is not running on 6 cylinders. After a few minutes, the condition gets worse and eventually cuts out. No faults showing on ECU (31) Any ideas?

 

[Mr.F]

Look at cold start bypass valve or air regulator (on RH side of plenum with hose running to front of throttle body. If it remains open then engine will be lean when warmed up. Works on a combination of electrical heater and bimetallic strip to open and close the by-pass shutter. So - open when cold, closed when warm. Doesn't show up on fault code checking.

 

[mrM]

another angle is to check out the airflow meter ive had this before on the z31 with the sypmtons you describe,the fault codes may show up ok but in my experience this does not mean the part isnt duff,you can spray a shot of carb cleaner at the thin wire element inside it as it can be dirty,it probably wont work but worth a go and wont hurt

 

[scb1957]

Hi Mike, thanks for your diagnostic info. You have confirmed what I have learnt in this huge journey to find out how this engine works. There are only 2 devices under the bonnet that don't appear to be connected to the ECU, that may have an effect on the engine. Do you know if these devices are still available, but on another angle, if I unplug them, they wont affect the ECU, therefore maintaining the status quo. Any input would be appreciated. Regards Steve.