Poor Running ?

[Wyn]

Still convinced this is an ignition/wiring problem.

In one

Fixed it at last
Decided to wire the ignition as simple as poss, so found this pic as a guide
Seems I didn't need to tho !

After checking the pic against my cars wires it was obvious someone had connected the ignition module + feed to the wrong side of the coil
i.e the - side, so after all that it was just one wire connected up wrong lol
How it got there I dont know, but my guess is someone may have known

Still atleast it revs over fine now so I can actually get on and enjoy driving it

 

[260Z TT]

Wyn,
Glad you got to the bottom of it eventually.
Go and enjoy it mate!Mark.

 

[twoforty]

so the module was connected the wrong way around or the coil?

 

[Wyn]

Go and enjoy it mate!Mark.

Cheers M8 I will

so the module was connected the wrong way around or the coil?

Yep, the module B+ wire was connected the neg side of the coil
Swapped it to the + side of the coil n the misfire has gone

 

[twoforty]

oh right, I thought you had tried swapping the wires on the coil and it made it worse.

 

[Wyn]

oh right, I thought you had tried swapping the wires on the coil and it made it worse.

You're right, I did
I swapped the two negative wires to the live side n the one live to the negative side, but as said the misfire was even worse that way round
What I didn’t try tho was just one of the neg wires to the live side, until today when I had that diagram to hand n noticed it was wired wrong

 

[twoforty]

Ah I see...good job! didn't someone else have the same problem as you? wonder if it's the same thing.

 

[Rob Gaskin]

Glad you sorted it.

As a matter of interest (or not) I think with old points ignition, coils can have the polarity reversed and still work. However they gow 'spikes' quickly. Is that right?

 

[Dale]

didn't someone else have the same problem as you? wonder if it's the same thing.

Not sorted yet, grrr!

I've just got rid of the old mechanical points and fitted a magnetic air gap type system and a new coil but I still have the same problem. I suspect it is the wiring though. I have two wires that were already there, if I connect both (as it was before) the engine fires ok but the tach goes backwards on revving, if I connect one of them the engine fires ok but the tach doesn't work at all, and if I connect the other the engine fires ok and the tach works ok. Both these wires show 12v, so I'm a bit confused.