96 Z24 1 and 4 spark plugs not firing

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96 Z24 1 and 4 spark plugs not firing

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Chevrolet Forum >> Past Vehicles >> Cavalier >> 96 Z24 1 and 4 spark plugs not firing

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96 Z24 1 and 4 spark plugs not firing - 8/9/2007 12:40:25 PM

charms0

Posts: 2
Joined: 8/9/2007
Status: offline

My '96 Z24 with 125k miles is not firing the #1 and 4 plugs and sputters. I swapped, then replaced both coils, had my ICM checked at 3 different Autozones(all ok), change the plugs, boots, MAP sensor, and fuel filter. I brought some spark plug wires to allow me to test the plugs. When I disconnect the plug wires on 1 and 4 the car starts and run with some sputtering. When I reconnect 1 and 4 and disconnect 2 and 3 the car turns but does not start. Also, when I let the car run for a while to see if the spark plugs will get the signal when the car gets warm unburned gas is heated in my converter and it glows red, so I know fuel is available.
Anyone know what could prevent 1 and 4 from firing. Looking in the book there are two signals ckt "A" for 1 and 4 and ckt "B" for 2 and 3 coming from the PCM.

Please Help........

Post #: 1

RE: 96 Z24 1 and 4 spark plugs not firing - 8/9/2007 10:14:23 PM

waltd140

Posts: 23
Joined: 6/28/2007
Status: offline

Spark starts at the plug. I would get a multimeter & take the wire off the plug. Then have a pal crank the car & check for voltage at the plug itself. Might flicker, which means plug is good.

Now trace back from there. Hook the wire to the plug & disconnect from the pack. If flicker / voltage then good. If not try a new wire or a good wire from another plug (but put it back before you forget where it goes).

Might be a wire is crossing with another. Are all the wires running where 1 is not crossing over another?

Another thing to think of is a bad pack (yep.. had 2 bad ones in a row before)

Hope this helps
Walter

(in reply to charms0)

Post #: 2

RE: 96 Z24 1 and 4 spark plugs not firing - 8/16/2007 3:00:40 PM

charms0

Posts: 2
Joined: 8/9/2007
Status: offline

It was the Ignition Coil Housing. Resistance readings were good, continuitiy was good between the coil contact and spark plug boots, yet it prevented the signal from reaching 1 and 4 boots. Thanks for the suggestion waltd140.

(in reply to charms0)

Post #: 3