Aphrodite

ok... next problem to deal with

My car was idling really rough and accelerating even rougher in lower rpm's... so I took it to the shop and it turns out my number 4 ignition coil was shorted out... so replaced that but still doesnt run smooth, so broke out the oscilliscope and checked the wiring going to the coil... and the red wire going to it is getting surges like it has a partial short which is causing the low rpm roughness... soo through all my attempts at troubleshooting this problem (Im still a noob when it comes to cars) I have come to the conclusion that I should replace the wiring there especially since it looks a bit corroded... so I was wondering where exactly these wires go and if they are part of a harness where I can purchase a replacement... because although I work on electronics and am confident I could just cut and splice in some wire of the same gauge I would prefere to do it properly.

and if Im just off in the corner of space somewhere on the wrong track any help would be appreciated, Im still learning

CanyonCarver

You might try checking the PTU per the FSM...... HERE and clean the connections.

Aphrodite

Thanks, i'll try that... time to break out the multimeter.

btw is that where the wires from the ignition coil go? or do they go to a module under the dash on passenger side(I forgot the name of it)?

CanyonCarver

C/P wires go to the PTU and then the ECU........ SEE HERE

Aphrodite

Ok, THANKS for pointing me in the right direction... I was checking the PTU and noticed it was not the same as the one in the manual, so I checked the adapter pigtails and noticed some of the shielding was gone... upon close inspection 3 of the wires were exposed and probably shorting with eachother, and one was broken completely... sooo I cut out the bad parts and spliced them back together, then ohmed it out to make sure good connectivity... apparently whenever the PTU was replaced they added 6 inch pigtail adapters not thinking that the longer cables would now be hanging down next to a belt so... let a wire bounce off a belt for awhile and soon it will be destroyed!... soo... its fixed temporarily but im gonna have to rebuild those pigtails, or throw them out and change the connector on the origional harness... but it runs freakin BEAUTIFULLY puuurrrzzz at idle and pulls hard through the whole power band now instead of just over 4000 rpm, WAAAY better throttle response and power... accelerates to 100 much quicker now... not to mention that fixed my 14 mpg problem (ran it about 100 miles and averaged about 26mpg), Im actually kinda glad my ignition coil shorted out so I found this wiring problem... I always had this gut feeling it had less HP then other 300zx's i'd driven... and now I know I wasnt just imagining it... man im sooooo happy. thanks again for pointin me in the right direction