How to test an ignition module.

[dan2286]

This question is not for a g body but I figure I would give it a try. I have a 2000 Grand Prix that has a miss. I got a paic of the cat glowin red hot after I drove it home, so I am sure I will need one of them after I fix the miss. So, becuase of the glowin cat I went straight to check spark. I found that the coil pack for cylinder 2 and 5 have no spark. I changed it with a known good one I had lain around and no change in the miss. What my queston is how do I test the ignition module, preferably where that coil connects to.

Thanks for the help.

 

[85 Cutlass Brougham]

Logic seems to dictate that the module is the problem.

 

[JESSE]

miss

a bad injecter will give you the same miss you need to ohm out your injecters, a lean condition will cause a miss good luck jesse

 

[dan2286]

Re: miss

a bad injecter will give you the same miss you need to ohm out your injecters, a lean condition will cause a miss good luck jesse

Isnt it a rich condition that sets a flashing check engine light and overheats the catylitic converter? I tested spark coming from the coils, two out of the three coils have spark, one doesnt. I have had bad injectors on this car and it has had a miss but it did not flash the check engine light and make the cat glow red.

 

[JESSE]

miss

you can check the coils with a test light,just take a piece of vaccum hose and cut in to six pieces. put the vaccum hose on the coil post and put the wire on the hose on all six ,start engine and use your test light by putting the light close to the hose. a bad coil will show a weak spark does this make sense to you?

 

[megaladon6]

the check engine light turns on for anything that could cause the emissions to go over a certain point, and to flash for anything that could cause damage to the cat.
first switch the "bad" coil to a different set of cylinders. if it works fine, check the mounting area/ground.
when you pull the coil, also check the condition of the 2 pins and put a voltmeter or noid light on them.

 

[JESSE]

test

i agree with megladon, it has been four years since i worked on a car with a dis system,but i used to know my sh*t! if a coil is not firing it will cause the engine to run rich, if you do the test like i said you will find out which coil is not firing ,try replacing that coil if it still doesn't fire the module is bad. the way a dis system works is the primary plug fires frist the current goes thur the block and fires the secondary plug ,some time the current will come thru the modlule and burn it out,try this first before you spend a lot of money i hope this helps you jesse

 

[dan2286]

Its fixed now. I did try swapping the coils and it was still havin problems with the same cylinders. I tried cleaning off the area where the coil sits and everything else around that and still no fix. That pretty much narrowed it down to the module being bad so, 130 bucks later it runs great now! Thanks for all of the help.

 

[79malibu]

miss

i have my 04 impala ss modded and once under wot i had the engine light come on flashing at me. car bogged down too but i found a tq management folder going into abuse mode that i didn't notice before and sent her lean. took my tuner and corrected that. 😀 no damage though cause i got full exhaust with headers + no cat but you at least better watch that cat now in case you didn't get by so lucky with it. 😱