Weak coil?

[MERCULES]

My Maruader is new to me, it is Lidio tuned.

The first time out it overheated, so I changed the antifreeze (weak) and burped the system, I noticed immediately afterwards the engine was running poorly and misfiring/breaking down under load, seemed to be worse after the engine warmed up.

I met up with my mechanic and he was surprised it was running so poorly and yet it would not set off a code of any kind.

I had a new set of plugs with me and we changed those, cleaned all the coils/sprayed them with silicone spray. Noticed there was a lot of moisture on two of them. (plugs that came out did not look too bad, nothing obvious)

150lbs compression in all cylinders, I noticed a big improvement right away but not 100% yet.

I put in a double dose of Lucas fuel injector cleaner, and I have about 50 miles on it since.

The car is very good but still misses under load a bit periodically when it is warmed up and been driven a while.

If the car will not trip a code how can I tell if I have one weak ignition coil.

[whitey]

ford uses a specialty tool to check individual coils i believe. if you buy new coils, buy motorcraft.

[cer0413]

My Maruader is new to me, it is Lidio tuned.

The first time out it overheated, so I changed the antifreeze (weak) and burped the system, I noticed immediately afterwards the engine was running poorly and misfiring/breaking down under load, seemed to be worse after the engine warmed up.

I met up with my mechanic and he was surprised it was running so poorly and yet it would not set off a code of any kind.

I had a new set of plugs with me and we changed those, cleaned all the coils/sprayed them with silicone spray. Noticed there was a lot of moisture on two of them. (plugs that came out did not look too bad, nothing obvious)

150lbs compression in all cylinders, I noticed a big improvement right away but not 100% yet.

I put in a double dose of Lucas fuel injector cleaner, and I have about 50 miles on it since.

The car is very good but still misses under load a bit periodically when it is warmed up and been driven a while.

If the car will not trip a code how can I tell if I have one weak ignition coil.
Same symptoms over here.

[RichardP]

Change spark plugs? Has little to do with bad COPs, but it helped for me.

[03mmmonroe]

ford uses a specialty tool to check individual coils i believe. if you buy new coils, buy motorcraft.

Get new Motorcraft coils. GO TO FORD RACING can get a set of 8 for just over $180 dollars. I have purchased two set in the past.

Better then purchasing one at a time.

[lifespeed]

03mmmonroe is right. Definitely don't screw around chasing the "one" bad ignition coil. I tried this and it was a colossal waste of time. And I did end up having more than one bad coil.

Just change them all, they aren't that expensive. Close inspection of my worn OEM coils showed arcing and burn marks on the secondary side of the coil. Given the number of members who have cured misfires and rough running with new COPS I think it is safe to say the originals are not that good.

The Ford Racing replacements do appear to last well, so you should be good.