Hi all, does anyone know of a way to test the ignition coils on a 87 2.5L? I'd like to know if there putting out enough, before I just go buy new ones. The only garage I found that would do it for me is Pepboys and they wanted $75!!!! Just to tell me weither there good or bad. I could buy new coils for that price. So the question is, can I test them myself and what would I need to do this? Thanks for any help.

It is unlikely both coils would be bad,, "the best test is to switch the coils" the easiest test is to take an old spark plug,, widen gap,, ,lay plug on grounded surface or wire ground...and watch spark on 1/4 and 2/3 coils.. compare the coils..the coil check in the haynes and chilton manual are effective ,,but a coil will test good then not be effective under compression........ .060 spark plug gap,are plugs O K??? some one may post image of test
always ground spark plug when test or check ,,arching to ground is bad for electronic components and can send you into electric joltola the spark on newer cars can hurt you badly, use care here the fiero will just knock some enlightment into you
most common cause of weak spark is plug wires, next cause bad connection,wires fraying next corroded bolts,screws,, next coil pack parts the module more likely to be bad than sensor
module ?? use only ac delco,,(unsure of performance of other brands) check bolts and screws holding module for rust & corrosion, a good connection is demanded here
the sensor is easily damaged (I know for certain) when removed pull stright out at the angle it mounts to block ,easier said than done .after market sensor ok ,use loctite of some sort on small screws to remount.. a loose sensor will create more havoc than I would in an all girls college dorm

heh thanks for the help I'll have to try some of that. For the record, I just replaced plugs and wires from Fierostore.com So I know those are okay.

Why do you want to check coils ??what does it run like ?? did you gap spark plugs at .060 check plug color of old spark plugs.. do all plugs look the same ?? an indication of engine condition is the condition of the plugs ?? compare plugs to the photos in haynes manual a weak coil plug will have more carbon be darker (sometimes) the strong coil plug would be leaner a lighter color

What I did with my '87 2.5L coils was to check the resistance with an ohmmeter on each one then compared the numbers. As uhlanstan said, rarely would both coils be bad. After checking the resistance I still was not convinced so I checked a new one at the auto parts store. All checked the same for me. You need paperclips or similar to check the primary side underneath as the slits are too small to get the ohmmeter probes in there. You can find these coils at the junkyard for cheap. All the GM DIS cars use the same coils. You will find them in Camaros, Bonnevilles, Berretas, ......ad nauseam.

ONCE AGAIN Hudini has out done me with a great escape from expensive parts ..It is unlikely the car you pull the coil from had a bad coil,,if you plan on driving Fiero,s, buying both coils from the car is a good idea.. the G M coils seem to be the best, a good idea to have an extra coil
Many yards have parts book which gives what FITS WHAT.. does not hurt to have an extra module assembly if price is correct !!

You can buy an inline spark checker tool for about $10 - hook it up between coil terminal and plug wire look for uniform flash intensity - or check you wire by using it between wire and plug. (Assumes good plugs)