how to tell if a coil pack is bad? [Archive] - GrandAmGT.com Forum

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GrandAmMe
05-25-2009, 11:10 AM
how can you test a coil to see if it is bad?

FromTheInside
05-25-2009, 11:36 AM
Take a multimeter and set it to ohms. Check to see if the resistance between the two spokes on each coil measure out the same... Therefore, you have three coils numbered 5-2, 4-1, and 6-3. Measure the resistance between spoke 5 and 2, 4 and 1, and 6 and 3. They all should be around .55 ohms or something. I am stating this from my own tests that I took a month ago so i don't remember too well. Just make sure all of them are around the same because I honestly doubt all of them went bad in the exact same way. Also, while the car is running, if you would like to check to see if the coils are charging up enough power to fire your plugs, (WITH CARE AND CAUTION) pull the plug wires out of the spark plugs (not the coils) and make sure that you see a nice blue spark indicating that enough voltage is present. The voltage of that spark is near 50,000 volts lol. If the spark is redish pink or something, then further investigation is required as it could be a damaged coil, module, or spark plug wire.

When pulling the wire, you should use a pliers made for the job and therefore not metal because I have gotten shocked and it sucks.

SikMindz
05-25-2009, 12:27 PM
Give it a handle of Jack and a gun. If it tries to hold up a liquor store I think it's time for a replacement...

rocketfast123
05-25-2009, 02:31 PM
Hard starting or no starting
Misfire/surging under acceleration
Wonky idle.

ltpats
05-25-2009, 03:09 PM
Take a multimeter and set it to ohms. Check to see if the resistance between the two spokes on each coil measure out the same... Therefore, you have three coils numbered 5-2, 4-1, and 6-3. Measure the resistance between spoke 5 and 2, 4 and 1, and 6 and 3. They all should be around .55 ohms or something. I am stating this from my own tests that I took a month ago so i don't remember too well. Just make sure all of them are around the same because I honestly doubt all of them went bad in the exact same way. Also, while the car is running, if you would like to check to see if the coils are charging up enough power to fire your plugs, (WITH CARE AND CAUTION) pull the plug wires out of the spark plugs (not the coils) and make sure that you see a nice blue spark indicating that enough voltage is present. The voltage of that spark is near 50,000 volts lol. If the spark is redish pink or something, then further investigation is required as it could be a damaged coil, module, or spark plug wire.

When pulling the wire, you should use a pliers made for the job and therefore not metal because I have gotten shocked and it sucks.

Ohm checking a coil is kinda hit and miss, it can ohm out ok but still be bad because a coil tends to act up when it gets hot, that's usually when it will break down.

OneFstGt
05-25-2009, 03:25 PM
Ohm checking a coil is kinda hit and miss, it can ohm out ok but still be bad because a coil tends to act up when it gets hot, that's usually when it will break down.

x2

GrandAmMe
05-25-2009, 03:31 PM
well before it did die it had a really jumpy idle and i mean really. Then after that it wont start at all and does not have any spark at the wire. How much can i get these for cheap used. This is for the parts car 1994 grand am not for my GT. Its a 3300 V6 motor

rocketfast123
05-25-2009, 03:42 PM
Should be at the junk yard. That kind of coil pack was used on all v6s around that time.
2.8mpi
3.1mpi
3800 I

FromTheInside
05-25-2009, 03:48 PM
I realize that, but it is still a check nonetheless. I went on and said to test the spark to make sure.

GrandAmMe
05-25-2009, 04:12 PM
i did check the spark. i took the plug out plugged it in a wire pressed it on a part of the engine and cranked it and saw no spark at all. i just looked at some pics and it actually looks like the plug wires are on the wrong ay. would this affect it also? i mean if they are on the complete wrong way shouldn't it still fire a bit?

rocketfast123
05-25-2009, 06:32 PM
It will sound like the timing is too far advance if it does fire, but after 7 years gas does go back

GrandAmMe
05-25-2009, 08:21 PM
i squirted fresh gas into the throttle body and nothing changed. I will change around the wires this weekend.