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not all cylinders when the weather is cold

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so, when the weather is cold ( Under 47°f ), and only in this condition, when i start the engine i don't have an ignition on every cyliinder. and the "SES" light is on.

i run in this condition and when the engine is hot, the light turn off and the ignition is ok on every cylinder.

some ideas....?     thanks and sorry for my bad English !

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Avez-vous exécutez un scanner de diagnostic sur votre voiture et a tiré tous les codes de la panne une fois que votre «service moteur bientôt" allume?


Have you run a diagnostic scanner on your car and pulled any trouble codes once your "service engine soon" light comes on? 

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Professur and Frosty,

spark plugs and wiring set are new. i don't have an OBD1 to pull the codes.  i feel that one or two cylinders are not operating and there is some smoke at the exhaust tip with a fuel smell until the engine runs correctely ( when it is hoy ).




(yes, it is the 1994 3.4 v6 firebird. )

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Don't need an OBD1 ... just a bent paperclip. If the plugs and wires are new, that would be the first place I'd look. Wouldn't be the first defective new part I'd ever installed. I take it you didn't have this problem before the tuneup? You might have a coil pack failing. In fact, it would be worth it to make sure you don't have wires cross talking on them. This might be useful. http://easyautodiagnostics.com/gm/3.1L-3.4L/ignition-coil-pack-tests-1

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Fire up the engine and have a bottle of water handy with a hole poked in on the cap.  Spray the manifolds down and watch where the water evaporates from first.  At least you can tell what cylinders are not firing first. Under the coil packs is a circuit board.  Those are prone to problems when they are old also cracked coil pack casings pop up as they age.  Since the car is cold some moisture  gets in either the coils packs or on the circuit board.  This would cause them to shut down a cylinder.  If you are going to replace one coil then do so but if you replace the circuit board then replace all of the coils.  I had this problem on a 1990 Cavalier with the 3.1l.  It took some time to diagnose it but it did pay off in the long run.

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plugs, wire and wiring diagram are ok: changed twice..    i had the problem before the tune up; it's why i changed this parts.

i wil change the 3 ignition coils in november, and have a look to the circuit board .  before, i will try to pull the codes.

thanks a lot for your answers and for the link.   

have a good day.





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So you had the problem before firing the parts cannon ... There's the necessary kernel of information. When you pulled the old plugs, did you inspect them? You can tell a lot about your engine by how the plugs look. Definitely read that article I shared before buying more parts.

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  • 2 months later...

Hi you all,

So, i bought an OBD1 to scan the car. The MAP SENSOR was out of order.  With the new it's ok !

Thank you all and have good new year fiesta !

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