Hi, was checking all components+ wiring etc because had a really bad missfire /hesitation all of a sudden car cut off wont restart and when it does come on cuts off again, so when i checked coilpacks+wiring harness all were ok i could see spark apart from one tryed different coilpack but made no difference so the wire harness the bit you attach to coilpack is faulty but ive used a multi meter on all connecters and get same reading but get no spark from one harness really confused what can i check also would car missfire that badly with one coil not working plz help thanx.

PTU (power transistor) is probably on it's way out

I had the same thing, my car cut out 3 times coming home from work, eventually after getting home i looked at everything like you have and it refused to start. I was soo pi**** off that I left the car for 2 days and tried it the 3rd day and it burst into life right away, turned out to be the PTU as Lymon says in previous post. I got one from Courtesy Nissan in USA, a S2 PTU with the adaptor looms as the plugs are different.

 

HTH Cheers John Crisp

PTU (power transistor) is probably on it's way out

but ive tryed two different ptu's

checked injector connectors as well ? (especially the one of the failing cylinder)

checked injector connectors as well ? (especially the one of the failing cylinder)

have checked all and cleaned them and made sure there all pushed in,as mentioned there was spark in 5 coilpacks so tryed different coilpacks on faulty one and made no difference so its deffo harness but i used a meter to check reading and its approx same on all six but theres no spark from one cylinder plz help really pi***d off thanx.

tried different sparkplugs ?

 

> would car missfire that badly with one coil not working

 

The car should still run and idle ok with one coil not working, be it a little lumpy

If it doesn't idle, there's probably something else wrong

 

other things you can try:

pull the widest plug from the PTU and check resistance of the wires.

from the top of my head, the middle thick wire (black) on every coil plugs runs to a single pin on the wide PTU connector (-) and the other pins all run to an individual coil plug (+)

 

the wires from the other/smaller PTU connector run straight to the ECU.

fuel pump control unit ,,,just a thought happened to me kept starting then it didnt then that was it ,never started after that

fuel pump control unit ,,,just a thought happened to me kept starting then it didnt then that was it ,never started after that

have bypassed control unit, weird thing is used another ptu and got spark from previously faulty coil pack harness and thought hopefully problem solved but when tryed starting car no difference and i did check ptu you before as well also i have hks iridium plugs which i have just cleaned and put back only had then approx 2000 miles so cant be them, im very confused now