I think I may have Spark issues
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 3,479
Likes: 92
From: Between Tally and Gatorville ,Florida
I think I may have Spark issues
Just changed plugs and wires( GM red wires) and thought of checking the spark with a held to wire type spark tester. The spark is intermittent in all cylinders. I checked my truck and cadi with same tester and spark is very fast and steady. could all coils go bad? is there something else i could check ?
Tech Contributor
Joined: Jan 2007
Posts: 19,475
Likes: 1,171
From: Dyer, IN
Just changed plugs and wires( GM red wires) and thought of checking the spark with a held to wire type spark tester. The spark is intermittent in all cylinders. I checked my truck and cadi with same tester and spark is very fast and steady. could all coils go bad? is there something else i could check ?
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 3,479
Likes: 92
From: Between Tally and Gatorville ,Florida
I should have given more info. Sorry. Engine has 100k and run,but had a intermittent miss. I thought I would change plugs and wires in hope that it would fix it.. However,the miss is still there while running at idler. When you hear the miss the spark goes intermittent for a second or two. I'm using one of those press to wire spark tester which i know they are not the best of tools. When I use the tool on my truck and on the cadi, the spark is constant so it's not the tool.
Team Owner
Joined: May 2001
Posts: 87,380
Likes: 1,593
From: Western NY
"Lucky" is well known for his ability to create sarcastic posts that add absolutely nothing to the discussion. "-r2h" was making note that this wasn't one of those.....
Tech Contributor
Joined: Jan 2007
Posts: 19,475
Likes: 1,171
From: Dyer, IN
I should have given more info. Sorry. Engine has 100k and run,but had a intermittent miss. I thought I would change plugs and wires in hope that it would fix it.. However,the miss is still there while running at idler. When you hear the miss the spark goes intermittent for a second or two. I'm using one of those press to wire spark tester which i know they are not the best of tools. When I use the tool on my truck and on the cadi, the spark is constant so it's not the tool.
1) Do you have a flashing check engine light?
2) Any misfire codes?
3) Is the miss only at idle? Normal driving?
4) Does the miss occurr cold, hot, all the time?
5) Any recent maintenace performed/history of car?
6) Is this is new problem? If not, when did it start?
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 3,479
Likes: 92
From: Between Tally and Gatorville ,Florida
It really helps if you provide details.
1) Do you have a flashing check engine light?
No
2) Any misfire codes?
will check late.r
3) Is the miss only at idle? Normal driving?
More notiable at idle
4) Does the miss occurr cold, hot,
all the time? all the times
5) Any recent maintenace performed/history of car?
new plug n wires
6) Is this is new problem? If not, when did it start?
1) Do you have a flashing check engine light?
No
2) Any misfire codes?
will check late.r
3) Is the miss only at idle? Normal driving?
More notiable at idle
4) Does the miss occurr cold, hot,
all the time? all the times
5) Any recent maintenace performed/history of car?
new plug n wires
6) Is this is new problem? If not, when did it start?
Hope this gives u a better idea
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
LOL 
WOW... I have a very simular issue right now. I have a very slight random miss. I cant even track it down to one cylinder yet. (I have to break out the TECH2 
) Anyway,,, I may have a bad coil and i plan on measureing each one for the correct resistance and doing a very close inspection on all aspects of the coil. Look inside the coil secondary tower and MAKE SURE the metal contacts inside are not burnt or corroded.
Next: " MEASURE THE HOT IN ON AND START power on the fuse that supplies the power to the coils and injectors." There are TWO test points on the TOP of each fuse. Measure each test point to chassis ground. YOU MUST read full battery voltage on the fuse with the ignition ON. If it's significantly LOWER than battery voltage,,,,,,,,,,,,,,,,,,,, your IGNITION SWITCH is causing the issue and is not suppling the coils and injectors the proper voltage to operate correctly.
FUEL
Read the voltage DIRECTLY on the battery and compare it to the voltage readings on the fuses that supply power to the coils and injectors. IF,,,,, theres a BIG difference, the contacts inside the ignition switch are dirty/burnt.
WOW... I have a very simular issue right now. I have a very slight random miss. I cant even track it down to one cylinder yet. (I have to break out the TECH2 ) Anyway,,, I may have a bad coil and i plan on measureing each one for the correct resistance and doing a very close inspection on all aspects of the coil. Look inside the coil secondary tower and MAKE SURE the metal contacts inside are not burnt or corroded.Next: " MEASURE THE HOT IN ON AND START power on the fuse that supplies the power to the coils and injectors." There are TWO test points on the TOP of each fuse. Measure each test point to chassis ground. YOU MUST read full battery voltage on the fuse with the ignition ON. If it's significantly LOWER than battery voltage,,,,,,,,,,,,,,,,,,,, your IGNITION SWITCH is causing the issue and is not suppling the coils and injectors the proper voltage to operate correctly.
FUEL
Read the voltage DIRECTLY on the battery and compare it to the voltage readings on the fuses that supply power to the coils and injectors. IF,,,,, theres a BIG difference, the contacts inside the ignition switch are dirty/burnt.
Last edited by Bill Curlee; Jul 13, 2012 at 01:06 PM.
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 3,479
Likes: 92
From: Between Tally and Gatorville ,Florida
LOL WOW... I have a very simular issue right now. I have a very slight random miss. I cant even track it down to one cylinder yet. (I have to break out the TECH2 ) Anyway,,, I may have a bad coil and i plan on measureing each one for the correct resistance and doing a very close inspection on all aspects of the coil. Look inside the coil secondary tower and MAKE SURE the metal contacts inside are not burnt or corroded.
Next: " MEASURE THE HOT IN ON AND START power on the fuse that supplies the power to the coils and injectors." There are TWO test points on the TOP of each fuse. Measure each test point to chassis ground. YOU MUST read full battery voltage on the fuse with the ignition ON. If it's significantly LOWER than battery voltage,,,,,,,,,,,,,,,,,,,, your IGNITION SWITCH is causing the issue and is not suppling the coils and injectors the proper voltage to operate correctly.
Read the voltage DIRECTLY on the battery and compare it to the voltage readings on the fuses that supply power to the coils and injectors. IF,,,,, theres a BIG difference, the contacts inside the ignition switch are dirty/burnt.
WOW... I have a very simular issue right now. I have a very slight random miss. I cant even track it down to one cylinder yet. (I have to break out the TECH2 ) Anyway,,, I may have a bad coil and i plan on measureing each one for the correct resistance and doing a very close inspection on all aspects of the coil. Look inside the coil secondary tower and MAKE SURE the metal contacts inside are not burnt or corroded.Next: " MEASURE THE HOT IN ON AND START power on the fuse that supplies the power to the coils and injectors." There are TWO test points on the TOP of each fuse. Measure each test point to chassis ground. YOU MUST read full battery voltage on the fuse with the ignition ON. If it's significantly LOWER than battery voltage,,,,,,,,,,,,,,,,,,,, your IGNITION SWITCH is causing the issue and is not suppling the coils and injectors the proper voltage to operate correctly.
Read the voltage DIRECTLY on the battery and compare it to the voltage readings on the fuses that supply power to the coils and injectors. IF,,,,, theres a BIG difference, the contacts inside the ignition switch are dirty/burnt.
Last edited by Dale002; Jul 14, 2012 at 05:24 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Take good voltage readings on the fuses. Just because the fuse reads good at one time, cycle the ignition switch on and off and see if you get the same voltages.
BC
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 3,479
Likes: 92
From: Between Tally and Gatorville ,Florida
OK, Checked all coils,wires and connectors for visual damage and corrosion. None noticed.
Checked Battery voltage ignition off and it was 12.5
Checked Battery voltage with ignition on 12.4
checked battery voltage at fuses 16,18 and 22 and it was 12.4 at fuse 16 and 18 and 12.3 at fuse 22.
Started engine and rechecked voltage at fuses 16,18 and 22. fuses 16 and 18 at 14.5 fuse 22 at 14.3.
Accomplished voltage check as recommend after cycling ignition switch and voltage remain constant with the above readings. I was kind of hoping of finding a bad ignition switch. I've cleaned them numerous time using your techniques.However, not on this car.
Checked Battery voltage ignition off and it was 12.5
Checked Battery voltage with ignition on 12.4
checked battery voltage at fuses 16,18 and 22 and it was 12.4 at fuse 16 and 18 and 12.3 at fuse 22.
Started engine and rechecked voltage at fuses 16,18 and 22. fuses 16 and 18 at 14.5 fuse 22 at 14.3.
Accomplished voltage check as recommend after cycling ignition switch and voltage remain constant with the above readings. I was kind of hoping of finding a bad ignition switch. I've cleaned them numerous time using your techniques.However, not on this car.