Cold idle mis fire

crita_76 · Post by **crita_76** » Wed Jul 30, 2008 8:21 am

Hi guys,
looking for a bit of help with my ET. Its a granny car, stock as. Problem is:
1. starts when its cold-a little bit lumpy but idles ok.
2. touch the throttle- really bad miss fire (2 cylinders) up to about 3000rpm
3. let the car warm up for about 10 minutes (1/4 up on temp gauge) and the car runs fine.

checked the distributer cap and it looked ok. plugs have been replaced. one thing that i did notice with the dizzy cap was it appeared as though it needed an o-ring or gasket. the surfaces didnt appear to match properly. i did use some silicone to seal it up though. when i replace the cap 12 months ago i had trouble sourcing one are there a couple of differant types.

Post by **etking** » Wed Jul 30, 2008 9:27 am

im guessing the AFM - might need some tweakage of the screw on it - also make sure the plug is nice and clean and well connected

or could simply be dirty plugs/fuel filter/injectors

crita_76 · Post by **crita_76** » Wed Jul 30, 2008 1:01 pm

A few months back when the weather started getting colder it was doing this. onceiIt stalled and wouldnt restart. l changed the plugs, coil and coil lead. it then started first go. by this time it was mid afternoon and the car had been sitting in the sun for the day. The car is left in the open over night.

et_rider · Post by **et_rider** » Wed Jul 30, 2008 2:18 pm

what about timing try cheaking the electric timing it should be 12 degrease advanced when warm i think or the timing belt make shore they are all setup dot to dot let us now how you go man good luck

crita_76 · Post by **crita_76** » Wed Jul 30, 2008 2:41 pm

timing is spot on. As far as valve timing goes, woulnd it run shit when its hot as well. Its a definite miss on one or two cylinders. but only when its cold

photoglossy · Post by **photoglossy** » Wed Jul 30, 2008 5:21 pm

Water temp sensor?

Post by **tassuperkart** » Wed Jul 30, 2008 5:44 pm

Plug leads M8
Cold and damp will amplify any resistance issues.

Start the car cold and run it in the dark and check around the dizzy cap and tyhe coil tower.

Ill be there plenty of St Elmos Fire around there.

Use quality SUPRESSED leads only.

L8tr
E

crita_76 · Post by **crita_76** » Wed Jul 30, 2008 6:13 pm

was waiting for that reply. also what brand dizzy cap is best. the bosch ones dont appear to be a really good fit. a bit had to describe but the dizzy itself appears to have a slot or groove around, but the mating surface on the cap is flat. if that makes any sense.

Post by **tassuperkart** » Wed Jul 30, 2008 7:07 pm

Just get one from, Nissan M8
Change your rotor button as well.
Yep there are a couple of different types. Might pay to take your dizzy in with you.

From memory there is sposed to be a rubber seal in that groove. I think???/.....cant remember..lol
L8tr
E

dexi_styles · Post by **dexi_styles** » Wed Jul 30, 2008 7:26 pm

tassuperkart wrote:Just get one from, Nissan M8
Change your rotor button as well.
Yep there are a couple of different types. Might pay to take your dizzy in with you.

From memory there is sposed to be a rubber seal in that groove. I think???/.....cant remember..lol
L8tr
E

yup where the cap meets the disy it has a rubber seal.

while your at it check the C.A.S as wel.

Cheers,
Dexi

crita_76 · Post by **crita_76** » Wed Jul 30, 2008 8:50 pm

checked out the dizy and leads before i drove home tonight. it was playing up when i started it. i couldnt see any leads shorting out. it only played up for a few minutes though. just to make sure, when i say miss fire i really mean mis fire. there is nothing there at all. kind of reminds me of when i mixed up the leads(wrong fireing order) except when it gets warm its fine.

dexi_styles · Post by **dexi_styles** » Wed Jul 30, 2008 9:09 pm

crita_76 wrote:checked out the dizy and leads before i drove home tonight. it was playing up when i started it. i couldnt see any leads shorting out. it only played up for a few minutes though. just to make sure, when i say miss fire i really mean mis fire. there is nothing there at all. kind of reminds me of when i mixed up the leads(wrong fireing order) except when it gets warm its fine.

does it get spark or no spark???

check the C.A.S. (its in the dissy) and see if its not dirty in there. I know its prob not cos if that is playing up its constantly no spark, i know i had it happen to me once.

crita_76 · Post by **crita_76** » Mon Aug 04, 2008 9:10 am

replaced cap,rotor and leads, little to no change. i did notice this morning that is was a bit smokey when i started it this morning. the first time that ive started it in daylight for a while. i work 12 hour shifts, so the car is parked between 7am and 7pm. it smelt like it was running really rich. could this misfire be a leaky injector fouling a plug when the car is not running? any other ideas?

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