How do I test my coil packs?
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,550
Likes: 2
From: Woodbridge VA
How do I test my coil packs?
I’m troubleshooting a hesitation while accelerating. It’s fine at wide open throttle. All plugs and wires have been replaced. No codes at all. I don’t think it’s the coils but I would like to easily eliminate them.
I looked at some videos on the web but I’m not sure I did it right. On the videos it says to test the ohms at the plugs. I tried to read the ohms on the coil it’s self, but could not get a reading. But was able to get a reading at the plug where they all look to come together. A picture is below with the reading. I think they all look good. This is the passenger side. The driver’s side was very much the same.
I looked at some videos on the web but I’m not sure I did it right. On the videos it says to test the ohms at the plugs. I tried to read the ohms on the coil it’s self, but could not get a reading. But was able to get a reading at the plug where they all look to come together. A picture is below with the reading. I think they all look good. This is the passenger side. The driver’s side was very much the same.
Melting Slicks
Joined: Mar 2004
Posts: 2,388
Likes: 403
From: Horseshoe Bend ID
If you trust your DIC, you should get one of these with a bad coil pack:
DTC P0351 Ignition Coil 1 Control Circuit
DTC P0352 Ignition Coil 2 Control Circuit
DTC P0353 Ignition Coil 3 Control Circuit
DTC P0354 Ignition Coil 4 Control Circuit
DTC P0355 Ignition Coil 5 Control Circuit
DTC P0356 Ignition Coil 6 Control Circuit
DTC P0357 Ignition Coil 7 Control Circuit
DTC P0358 Ignition Coil 8 Control Circuit
DTC P0351 Ignition Coil 1 Control Circuit
DTC P0352 Ignition Coil 2 Control Circuit
DTC P0353 Ignition Coil 3 Control Circuit
DTC P0354 Ignition Coil 4 Control Circuit
DTC P0355 Ignition Coil 5 Control Circuit
DTC P0356 Ignition Coil 6 Control Circuit
DTC P0357 Ignition Coil 7 Control Circuit
DTC P0358 Ignition Coil 8 Control Circuit
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
The best way to test coils is with an ac delco st125 ignition/spark tester or equivalent. It will load test the coils and wires. Pull a plug wire, plug it in and groud it (jumper wire with alligator clips works well). You can also unplug the injector for the same cylinder. Start the engine. It should fire consistently, if not swap in a known good wire and try again. If you do not get a good evenly timed spark, the coil is bad. If it passes, that coil and wire will fire under any load.
I use these all the time. They don't lie. Test all 8 coils. If they pass, keep looking. Here is a YouTube clip with a demo, and no that's not me. Not the best, but at least you can see what it looks like
I use these all the time. They don't lie. Test all 8 coils. If they pass, keep looking. Here is a YouTube clip with a demo, and no that's not me. Not the best, but at least you can see what it looks like
Instructor
Joined: Apr 2008
Posts: 142
Likes: 11
I’m troubleshooting a hesitation while accelerating. It’s fine at wide open throttle. All plugs and wires have been replaced. No codes at all. I don’t think it’s the coils but I would like to easily eliminate them.
I looked at some videos on the web but I’m not sure I did it right. On the videos it says to test the ohms at the plugs. I tried to read the ohms on the coil it’s self, but could not get a reading. But was able to get a reading at the plug where they all look to come together. A picture is below with the reading. I think they all look good. This is the passenger side. The driver’s side was very much the same.
I looked at some videos on the web but I’m not sure I did it right. On the videos it says to test the ohms at the plugs. I tried to read the ohms on the coil it’s self, but could not get a reading. But was able to get a reading at the plug where they all look to come together. A picture is below with the reading. I think they all look good. This is the passenger side. The driver’s side was very much the same.
Did you ever see a resolution to this issue? I think my 99 FRC is doing the same thing, intermittent misfires, unburned fuel out of the tail pipes over time etc. any info would be much appreciated!
Thanks!
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,550
Likes: 2
From: Woodbridge VA
Hope this helps.
