PO354 DTC .... swapped with another coil and still have the same code (and misfire)coil connector looks fine, Is it possible the plug is bad?

 

P0354 Ignition Coil Primary D / Secondary Circuit Malfunction

which coils did you swap?

heres the cylinder order just to make sure you know which coils you swapped.

front
5 1
6 2
7 3
8 4

 

I blew out the number 4 spark plug(pass side rear) time serted it replaced all coils and plugs restarted and have PO354, took an old coil and swapped out number 4 with same results. put the new global back in checking connections carefully with same results.

 

when it blew out did the coil break where it mounts? maybe it pulled the wires loose where they go into the plug. what kind of spark plugs did you get?

 

yeah, it broke the mount spark plug with boot were on top of engine. rest of coil left hanging. I used Autolite APP103's they were out of stock on the AP103's

 

grab one of your old plugs and replace that one spark plug. if its better then replace all the plugs with motorcraft. the modular engines dont like many aftermarket plugs. some people get away with it and others dont. the only plugs so far that we havent had complaints about are ngk, denso, and motorcraft in these engines. other than that i'd still check out the wire that goes into the plug just in case.

i've never had a problem with autolites but members on here have gone as little as 40 miles on autolites in the modular engines.

 

Thanks, I will give it a shot in the morning and update it here -Mark

 

I compared the connector to the others and this one seems weak looks as though it was "crimped" I think it was damaged when it ejected the spark plug. the insulation is intact however, I'm sure many of the strands or wire inside are damaged.I am hoping Ford sells a replacement connector without having to replace the entire harness. Any comments would be appreciated.Thanks-Mark

 

swapped the plug, same results. plug appears that it is not firing at all-wet.
I am wondering if the PCM was damaged? I would think if the wire was damaged it would fire intermittingly? help....

 

http://www.source-products.com/publi...l/ignition.htm

Looks like the one you need is 99-8334. Give them a call.

 

thanks glc, that's exactly what I'm looking for! Do you know if it's common to have this problem along with the ejection? I don't recall seeing other people mentioning this.

 

Hope you didn't bend the valve/chip the seat. - It Happens. Always vac out the chamber and cylinder. You have to compresion test to be sure.

Also, never EVER use these plugs -

 

What happens with these plugs???

 

Wrong heat range for the modulars. The only Autolite you can get away with is the Coppers. 103's are Platinum's.
Their made by Honeywell. Honeywell also makes the Motorcraft plugs for these engines. The Motorcraft is made per Ford Spec.

I tried the Autolite's quite few years back. Made it about 40 miles when 2 cylinders began to misfire. At the time, nothing was open so I reinstalled my old Motorcrafts and she ran great!

If you look close, you can see the discoloration on the Autolite plugs. These were pulled from my misfiring cylinders.

 

WOW!, Looks like I wasted $34 and a couple hours of my time! I think I can swap them with a new set of Motorcrafts in a bout 45 minutes now that I am soo familiar with R&R'ing plugs and cops on a 5.4! Hell I remember actually being intimidated by the process just 6 months ago!Thank you for your valuable input. I picked up a new c.o.p. pigtail from the local Ford dealer here ($30) After I replace that I will update if that fixes the P0354 code, then off to the dealer for a set of Motorcrafts. -Mark