06 f150 5.4l 3v 173k new plugs new injectors new catalytic converters.
before i touched the truck i did my research. ive had parts on the shelf waiting to go in. i recently had a leaky injector collapse the driver side cat. so while i fixed that i decided it was a good time to install plugs and coils. i've read numerous posts on which coils to buy, the consensus is stay with the good names accel msd granatelli if you aren't buying motocraft. i ended up buying ganatelli mpg ones. it may be snake oil, but i figure the higher voltage can only help. so at the time of major repair i installed them. when i started it up i had a misfire and three cel for primary/ secondary circuit. so i took them off to get them out of the equation of the bigger repair. they sat on the shelf for some time now. did an oil change and decided to put them back on since the truck is running good. instantly i have 4 codes and a cel. p0351 and such, same primary secondary on cylinders a b e g. i went to the web and found a post that said granatelli has a high failure rate usually within a year. but 4 out of the box?
so i replaced those four with the old ones. thought it was good for a minute, but on my drive to work cylinder c decides to join the fun, firing randomly. after work i changed that coil back and drove home. seemed to run ok on the 3. so that makes 5 out of 8 my truck doesn't like.
i checked them with an ohm meter .7ohm primary 6.5k secondary. which from my readings should be good..... am i missing something? they have a solid wire rather than the motorcraft spring which is shorter in the boot. would the truck know if if was trying to push a double gap jump? thought of putting springs on new coils. but frankly tired of swapping them out... not too many negative reviews out there on them but i feel like something wrong to have 5 out 8 throw codes. dg511 sound a lot better right now.....

 

I would put new springs and boots on the coils if you haven't done so already..I bought some DENSO'S on Amazon for $27.00...cleared my miss right up..

 

I have put in three of these shelf its
1992 Explorer
2001 F250 Superduty
and now my 1995 F150 Eddie Bauer
I find them very useful, and yes the visor situation sucks but I live with it.

 

I looked at the Granatelli COP's when I was deciding what to get. They weren't rated very well on Summit's website, so I steered clear of them. I ended up getting MSD "Streetfire" coils, as they were rated very well, and I've had very good experience with other MSD products. I very well may still end up regretting my decision, but I still have the stock COP's to fall back on. I've learned through reading many posts online, and a little first hand experience, that you should stick to Motorcraft/OEM Ford parts on these trucks.

 

If in fact those coils give higher voltage then it would stress the boot insulation and plug porcelain . Once you punch threw the insulation it is bad forever . More is not always better .Plus if you didn't start with new boots and clean plugs, things would go wrong even putting back orig coils, once a carbon track is set up it breaks down faster . High voltage protection was my trade for 40 years, been in more than one explosion .My highest experience was 765,000 volts on AEPs line in Ohio .

 

Well, the coil only makes the voltage required for the spark to jump the gap, so it doesn't matter what your coil puts out just as long as it's adequate. The "voltage rating" of an aftermarket coil is the maximum voltage it can produce, not what it makes on every spark.

R.