Poor Running ?

[Wyn]

sounds like a faulty module.

Well I just tried a “brand new” dizzy that came complete with “new module“
So unless they both have exactly the same fault?
I cant see it but you never know

 

[Wyn]

what does your rev counter do when it missfires?

The rev counter is taken from the coil isn't it?
Could the rev counter cause it

 

[grolls]

The rev counter is taken from the dizzy isn't it?
Could the rev counter cause it

If it had a short in it, I doubt it though as it would be all the way through.

 

[twoforty]

So it's defo ignition then.

Sounds like you have covered pretty much everything!

Checked the grounding between the engine and battery? battery and the chassis?

Checked the voltage to the coil?

advance mech? sticking maybe?

 

[twoforty]

I see on your first post it runs on sometimes...running lean or ignition retarded too much maybe...have you checked the timing advance mech is working? and that it's set right in the first place.

 

[Wyn]

So it's defo ignition then.

Sounds like you have covered pretty much everything!

Checked the grounding between the engine and battery? battery and the chassis?

Checked the voltage to the coil?

advance mech? sticking maybe?

If it were that poor it would shorley cause starting probs aswell, deffo on cranking ?
That it doesn't.

I see on your first post it runs on sometimes...running lean or ignition retarded too much maybe...have you checked the timing advance mech is working? and that it's set right in the first place.

I checked the vac mech by sucking on the vac pipe and it seems to move ok without any obv air leak
As for setting it up in the 1st place 4***s "tuned it" a few weeks before I brought the car from the previous owner

It ran sh1t from day one

 

[Albrecht]

As for setting it up in the 1st place 4***s "tuned it" a few weeks before I brought the car from the previous owner

It ran sh1t from day one

I think you should reserve judgement about that situation until you hear their side of the story. Have you asked them about it?

If they were brought a car that was running badly, and the owner didn't want to go to the full expense of putting it right by exploring all possibilities, then I very much doubt that they would have wasted too much time on it.

The person who owes you a full explanation is the person that you bought it from, nobody else.

 

[twoforty]

Check the rotor arm at the end, the metal section maybe too wide causing it to crossfire at high revs....take a photo and compare to one off another members car on here.

 

[Mr Ex]

Does the rev counter wave about when it misfires?

Take it on full throttle somewhere in third or fourth and press the clutch & switch the engine off at the same time (this is called a plug chop) & check all the plugs & take a pic & post it up & if some are different colours take them as well.

I think the dizzy is too far advanced what is it timed up at?

 

[Wyn]

I think you should reserve judgement about that situation until you hear their side of the story.
The person who owes you a full explanation is the person that you bought it from, nobody else.

No I haven’t n maybe I should. As you say maybe the line was drawn before I brought it?
I’m just saying that from day one when I collected the car it wasn’t running right and that they had tuned it only a few weeks before hand. By that I hope/ assumed they would have tried/ set all the obvious?
No mention of any issues in their invoice tho?


As for the rotor arm I’ve tried 3 now !
The original, a new one I brought with the cap n leads n one that came with the new dizzy
Will look at maybe changing a few wiring plugs next, fuel flow n maybe even disconnect the rev counter just to rule it out

Need to get it sorted so I can get on with fiddling with the next bit

 

[260Z TT]

Have you tried checking the cam/ distributor timing?
I have seen many cars in the past that are either one tooth out on the dizzy drive, or even 180 degrees out, meaning that plug leads have to be rotated!
Another one to check, where is your Facet fuel pump fitted?
When I first got my 260, it was running on triples with a Facet pump. The pump had been fitted in the engine bay, in place of the fuel filter. When engine bay temps rose, car used to cut out. Get checking!

 

[Wyn]

Does the rev counter wave about when it misfires?
I think the dizzy is too far advanced what is it timed up at?

Correct me if I’m wrong, but if the rev counter hops about when it misfires it must be an electrical problem?
If it were fuel related would the rev counter flicker or just die when it misfires ?
I can try a plug chop but with an elec misfire will it show up or will it misguide ?
As for the timing I honestly don’t know what its set to
I marked its original position as it was set to when I brought the car and have tried various amounts of advance n retard, but all to no avail.

 

[Wyn]

Have you tried checking the cam/ distributor timing?
I have seen many cars in the past that are either one tooth out on the dizzy drive, or even 180 degrees out, meaning that plug leads have to be rotated!
Another one to check, where is your Facet fuel pump fitted?
. Get checking!

If it were that would it rev ok one minute but miss the next?
I cant see it
If the cam/ dizzy timing was out then it must be out with no in between ?

The pump is mounted well away under the rear rear body section
The filter looks clear aswell

 

[260Z TT]

I read your thread from start to finish last night and was only picking up on things that others hadn't. If your fuel pump is under the car, then you should have no fuel problem.
I also read at one point, you had said that it would just die at higher revs. If your rev counter is bouncing around, then it must be electrical. Are all terminals to coil tight?
Have old ballast resistor wires been joined together badly, then taped over? If they are, then you will get a poor 12v feed to coil, I always solder wires together to eliminate this from happening! Never heard of a Z tacho giving a misfire before, just one unit failed in 28 years of working on zeds!
Don't give up, we are all here to help. Pity you are not nearer, or I would be tempted to come and check it out for you!

 

[Wyn]

Don't give up, we are all here to help.

Appreciate the offer of help, inc those not seen!
Yep the pump is under the car
Having driven the car a few hundred miles plus now the prob is still more or less the same.
From cold and after each time it cools I notice it will slightly rev higher for the 1st few gears or so. As it warms and into the journey the misfire will progressively happen at lower rpm until it misfires as low as 4k, but then randomly it will rev to 5k+! Certainly the way it misfires violently it feels like ignition to me.
As and when I’ve changed a part and tried it again it does exactly the same thing each time. The rev counter seems unlikely but having asked a few peeps it seems a faulty rev counter can cause a high speed misfire? So it sometime to look at and costs me nowt to try anyway along with re-crimping the wires to the coil/ dizzy as advised.
Looking through the invoices I have for the car it seems Fourways previously fitted the 280 dizzy etc, so I would assume they know how to fit it/ wire it up correctly. But yes a wire where I guess the ballast resistor would be have been next to the coil has been soldered up.
As for giving up not on your nelly lol. Ive a track day booked @ Bedford this weekend n to be honest if my "other car" fails the noise regs I can see me coming back n taking the Zed, misfire or no misfire lol

I will sort it !!

 

[Rob Gaskin]

If you run out of ideas it might be worth getting it tested on something like a Crypton Tuner (showing my age now). That should establish fuel/air ratio, timing, lead problems etc.

 

[Dale]

I don't know how I've missed this thread, but I seems that I am having almost exactly the same problem!

I can't call my misfire a 'violent' one, more like I'm 'hitting a wall' at about same rev range as you, and lose all power until I ease off slightly.

I've only tried changing the HT leads, checking the plugs and adjusting the timing slightly so far, none which have helped.

The one thing that stands out from reading your symptoms, which I never even considered could be related before now, is that my rev counter also dances about wildly! That can't be a coincidence, surely?

So how is the rev counter wired in relation to the ignition? Would a faulty unit cause it, or somewhere in the wiring itself?

 

[twoforty]

If the rev counter dances then the problem must be in the low tension side of the ignition

 

[twoforty]

Guys pull the low tension wires off your coil and connect them around the other way....maybe the coil polarity is wrong. Worth a try.

 

[Dale]

You may have something there. Not that long ago I had a fauilty ignition switch that wouldn't 'switch off', which meant I had to stall the engine to stop it. I also disconnected the coil so it wouldn't burst into flames, so I may have wired it back up wrong after I replaced the faulty switch. I'll try that, ta.