One or two cylinder not firing

If US version, first confirm/deny if the frequency valve is vibrating when the engine is cranking or running. If it is (and it should be whenever the engine is running or cranking), then go after checking the ignition system components.

 

Depends - when something goes wrong in the Lambda system (like losing +12V power to run the frequency valve), the fuel delivered to all cylinders goes way lean. Depending on how equal the basic fuel delivery is to each cylinder was to start with (and no fuel distributor is perfect), some cylinders may miss more than others in that condition. It's a super easy thing to check so best to rule it in or out before doing anything else IMO -- you won't even get greasy

 

Normally, IMO, the usual suspects for a cylinder(s) misfiring are in the ignition secondary - wires/connectors/plugs/dist cap. That's where I'd start. As silly as this may sound, a good, simple check is the darkness test. Start the car outside in the dark (darker the better) and observe for any visible sparking/glowing around the distributer cap/wires. Unfortunately, with the extender covers, you won't be able to see the wires from that point down to the plugs but it's still a worthwhile test. It's sometimes quite a light show!. There should be no sparking visible anywhere. A water mist from a spray bottle will REALLY show up any 'leaking" wires/distributer cap cracks, etc.

BUT... since you are talking about the car NOT running properly after storage when it DID run OK prior to storage, it could also be a clogged injector and, with the engine sitting for 6 months, that's not an uncommon thing, especially if the engine was not run for a few miles with some stabilizer in the fuel before storage.

Then there's the oddball stuff - mice eating the wires, etc...

Good luck; let us know what you find.

 

*Bad gas
*Fouled plugs
*Fuel injection in that order.

 

Maybe a mouse chewed on one of your plug or distributor wires and fouled the ignition system... It was sitting in one's warehouse waiting for your new windshield...

 

Mine did that once, turned out to be an ignition lead. It was easy to find using a timing light, I just clipped it onto each lead until I found one that wasn't triggering the light. I then swapped plug and extender to verify but then just replaced all of the leads along with the plugs, caps and rotors... typical "while I'm in there" mission creep.

 

In the past my 328 had also done it. I did not have a timing light but used a spare plug grounded to the block to look for spark when engine ran. Found bad leads so they were replaced with a new set.

 

Mike,
Any update?
I vote for bad gas. Add fresh fuel and an Italian tune up.

 

Mike,

I had something similar. I did everything. New plugs, built new wires, got rid of the plug extenders, etc. Thought it was even the digiplex.

It ended up being the distributor rotor. Please change those first. I say this because its easy and the least costly thing you can do. Ten dollars each. The metal on the tip and points do tarnish over time, I did try to polish it first, but a new rotor is what solved my problem. Good luck

 

and coils...

Guido

 

Check for cracks in the rotor plastic. Also, check for corrosion on the extentender tips and on the tips of the distributor points. How is the ground on the battery? has it come loose?

 

When mine gets real low on gas and has sat for a stretch it will run like this for a few miles but clears up. I figure it must be the water in the ethanol. I never figure it out but since it always clears up, I don't have to. Maybe coming from the fuel side though.

 

Bad contact in the connection between coils and distributor also makes it possible that once in a while 1 or 2 cil refuses to work. Check entrance of that wire to the coil. To hit all possibilitys..
Guido

 

You can pull the wires/extenders and check the resistance with an ohmmeter. For resistance wires, 7kOhms/foot is a reasonably "normal" figure. More importantly, there should be no wires that are dramatically different. HOWEVER...the resistance could be OK but a crack or carbon track in the insulation/extender could still cause a misfire and not show up in a resistance check.

In the "old days" periodic replacement of ignition wires was just a normal maintenance thing. We replaced them at each tune-up. But admittedly, that was back in the days of points and carbon impregnated resistance wires. But carbon tracking is still just as much a possibility as it always was and it was/is a very common failure mode for distributer cap-caused misfires.