mbarazeen

I have an Expedition now at 507,000 km, I am not sure if the previous owner replaced the spark coils as a routine, when I purchased it at 270,000 km 3 years back I replaced the spark plugs. i was troubleshooting miss fire issue during acceleration and found out that sockets connecting spark plugs were not giving proper contact, some are with broken lock. if i start in the morning and drive without sudden acceleration it runs fine. some times i used to stop on the way and try to adjust the connectors to stop misfire, then it runs fine for some time.


I decided to change connectors and spark coil, ordered below items. the original coil and connectors are different type.(see picture attached)


My question is


1- is there anything that i should worry about when replacing the coils with new ones. i could not find the right type for this price,


Coil
http://www.ebay.com/itm/DG511-Igniti...19.m1438.l2649


Adaptor
http://www.ebay.com/itm/8pcs-Ignitio...72.m2749.l2649


I have DMM and LCR meter too to test and compare both new and old coils.


2- Can i still use the new one if i find it slightly different?
3- Any risk of damaging PCM?
4- is it required to maintain the polarity while soldering new connectors


Thanks
Razeen