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Help - Running on 3 cylinders!
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Author:  joyce1bro [ Sat May 24, 2014 12:09 pm ]
Post subject:  Help - Running on 3 cylinders!

Hey,

Well Ive been having a little trouble with my 1293. The car has been a bit of a pig lately with some flat spots and it absolutely loves to drink! I started looking at plugs first and possibly timing which yielded a very slight improvement, also looked at the carb (HS4) and oil in the dash pot and all is ok. I then decided to check if all cylinders were firing by starting the car and removing the leads one at a time. On number 3 I took the lead off and nothing!! no note change, no drop in idle, no nothing! I thought that I might have blown a HG so did a comp test. Numbers were between 158 and 164 across ALL cylinders. I checked if there was spark getting to the plug and there was, I swapped a lead out to see if the number 3 lead was faulty (even though it had good spark) and nothing.. Checked the resistance on number 3 lead and it was about 1.86 (note number 4 lead was about 2.1).

I pulled the dizzy cap off to check it and it looked ok. To be honest I only looked for excessive wear or corrosion as im not an auto electrician. I did get some 1200 grit and give the rotor and the cap points a little scuff to make sure. Still the problem remains...

Am I right in thinking that the Dizzy and or Coil is knackered? how can I find out if it is? can I rebuild or is it better to purchase a new one? if so is there a better dizzy for a fast road engine, as I will be upgrading the head, cam and carb etc...

What I do know;

1293
23D Electronic Dizzy - Timing is at about 10deg
Lumination Coil
Lumination 8mm leads
BP6ES Plugs - about 3 wks old and yes i have tried other plugs
Single HS4
Small Valve head
Compression is 158 - 164 across all 4 cylinders
There is spark at the end of the lead to number 3 - I thought the spark might be weak so I bypassed the ballast resistor for a greater spark with no difference

EDIT: Also worth noting that the number 3 plug actually looks like its burning, its the same colour as the other plugs.. Im not sure if its kicking in at a higher RPM rate or its because maybe the fuel is igniting on its own somehow during acceleration? but still the car seems to have flat spots and compared to my mates 998 his will for sure stomp me...

Appreciate the help.

Author:  MiniVLT [ Sat May 24, 2014 12:36 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Sounds like a dud #3 spark plug to me by your description and fault finding!
How long since you replaced your plugs? Maybe time for a new set, shouldn't be a costly exercise, $20 or so!

Cheers Shane

Author:  mini0998 [ Sat May 24, 2014 12:45 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Try swapping number 3 and 2 spark plugs and see if the miss moves to number 2 cylinder. If not then try the same with the plug leads. Then I wound try replacing dizzy cap.

Author:  joyce1bro [ Sat May 24, 2014 12:54 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

I have swapped plugs and leads with the same result. Even bought a new plug and it was the same...

Author:  MiniVLT [ Sat May 24, 2014 12:59 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Doh, I didn't see the plugs were only 3 weeks old!
That's pain medication for you!

Cheers Shane

Author:  Thorlek [ Sat May 24, 2014 1:04 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Perhaps a problem with valves? and no fuel is getting into the cylinder on the intake stroke, hence, nothing to burn when it does spark?

Author:  joyce1bro [ Sat May 24, 2014 1:11 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Thorlek wrote:
Perhaps a problem with valves? and no fuel is getting into the cylinder on the intake stroke, hence, nothing to burn when it does spark?


thats what I thought as well but wouldnt the compression test see a drop if the valve was open? or sorry you mean its stuck shut? I pulled the rocker cover off and hand turned the fan to see if the valves were opening and closing and if the clearances were ok and they seemed to be fine...

Im pretty stumped...

also heres a funny thing... the plug itself looks as if its burning... it looks the same as the other plugs... but once again... you take the lead off and no change in idle...

Author:  kiwiinwgtn [ Sat May 24, 2014 1:26 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Unlikely to to be the coil if its just number 3 cylinder. Does the plug spark if you unscrew from head and hold it close to the head and spin the engine.

If its just one cylinder not sparking then you only have three choices. Plug, cap or lead

Author:  boomini [ Sat May 24, 2014 1:38 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Stupid question time. Are the plug leads in the correct posistion?

Author:  drmini in aust [ Sat May 24, 2014 1:41 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Does #2 do anything when you pull the lead off? If you have a big cam in and pull #2 or #3 lead off at idle, you would swear neither is working.
IMO it's because of the siamesed inlet ports.
Don't expect them all to drop the same rpm when you pull a lead, it ain't an Alfa...

Author:  joyce1bro [ Sat May 24, 2014 3:18 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

umm according to the previous owner it has a 266 cam "at best". And yes number 2 drops in idle.

Author:  Phil 850 [ Sat May 24, 2014 4:22 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

You could rotate the dizzy cap 180 deg and move the plug leads 180 back to where they were.
Now see if #3 is the same or the problem has moved to #2.

Some leads/plugs will fire with no load (sitting on the head) but with compression pressures may not have the strength to fire.

Author:  joyce1bro [ Sat May 24, 2014 5:54 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

Phil 850 wrote:
You could rotate the dizzy cap 180 deg and move the plug leads 180 back to where they were.
Now see if #3 is the same or the problem has moved to #2.

Some leads/plugs will fire with no load (sitting on the head) but with compression pressures may not have the strength to fire.


maybe i'll give it a go... I might re check the tappets as well..

Author:  9YaTaH [ Sat May 24, 2014 6:17 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

MiniVLT wrote:
Doh, I didn't see the plugs were only 3 weeks old!

Cheers Shane


Newness don't mean a damn thing these days :cry:

Author:  joyce1bro [ Sat May 24, 2014 6:28 pm ]
Post subject:  Re: Help - Running on 3 cylinders!

9YaTaH wrote:
MiniVLT wrote:
Doh, I didn't see the plugs were only 3 weeks old!

Cheers Shane


Newness don't mean a damn thing these days :cry:


haha agreed. but i did buy 1 new plug to test and it didnt work either.. what a waste of 5 bucks ahaha

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