My N/A has developed a missfire.....

On the journy home it cleared after, 1/2 a mile?

 

Anyway seems more consistant now, ive pulled all the connectors off and each one makes a change in noise apart from the one at the back on the right of the engine, as u look at it, Behind all the pipes etc....

 

I managed to get a knife between the pipes and prize the connector off, if this isnt creating a change in noise is that likely to be the problem zone?

 

Is getting to this connector hard? being behind loads of crap, if so Theres no way i can try a diff coil pack as im a total newbie.

 

Any ideas?

Probably needs the injector connector cleaning. Bit closer to the centre of the engine than the coilpack

Umm right gone out the morning to clean the connectors, started her up before i done anything, and she sounded fine, took her round the block, no problems?

 

Can these things cure themselves somtimes?

It was a cold damp night as well

It's a very common problem with the 300zx.

The connectors become britle over time and the rubber seal that keeps them pressed in and secure gets lost over the years.

 

You can rewire all the connectors to the coil packs and injectors if you are frequently getting this problem. I did this on mine. You just need to know how to use a soldering iron and obtain the new connectors, I think the ones form a pulsar fit if I remember rightly, obviously you need two sets of these and you will have a couple spare (pulsar is 4 cylinder).

 

Another cause if it's not the coil pack or injector connectors could be the PTU, although the most common fault with this would effect all the sparks and not just one.

 

If you want to test the coil pack individually, disconnect the fuel relay, remove one coil pack and attack a spark plug to it, earth it to the plenum and crank the engine to see if you are getting a spark.