The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Uh-oh...

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Got an engine miss all of a sudden.
P0357 OBD-II Trouble Code: Ignition Coil G Primary/Secondary Circuit Malfunction.

I swapped the cyl 6 and cyl 7 coils and the code stayed at cyl 7, wires and connector look good visually.Any ideas?
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
blacksheep-1 said:
Plug?, check connectors including the little weatherproof doojobby things, it's easy to mess those little pins up
Everything looks honky dory.....I am at a loss and I really want to go to Laguna Seca Saturday :(


I will look again. Thank you.
 

Grant 302

basic and well known psychic
If not the plug, COP, or harness to the COP end...then look all the way back to the PCM for any possible shorts or wear thru insulation. With all the humid weather lately, I suspect bad contact in one of the pinned connections somewhere along the way. I'd try a little contact cleaner and dielectric grease starting on the COP side.
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Grant 302 said:
If not the plug, COP, or harness to the COP end...then look all the way back to the PCM for any possible shorts or wear thru insulation. With all the humid weather lately, I suspect bad contact in one of the pinned connections somewhere along the way. I'd try a little contact cleaner and dielectric grease starting on the COP side.
It was the spark plug. I guess a fresh set is in order. 25 inch pounds torque, yes?
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
You know, I just love this place. Did I ever mention that?
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
In the past when I needed plugs i got a misfire code..
The coil code had me worried when I moved the coil and the fault stayed with the cylinder.
Those plugs aren't very old...especially since the car really only sees track days, and most of those were shortened by brake failures.


How often are you guys changing plugs?
I'm using the NGK Iridium plugs that JDM engineering recommended when they built the motor.
 

ArizonaBOSS

Because racecar.
Moderator
8,730
2,734
Arizona, USA
BOSS 302S manual says change them every 6 hours of track time. I've been changing them every 6 months or so...which is a lot more. I'm starting to change them more often as the car definitely idled smoother with the new plugs after the last change. Plus you can read the plugs to make sure everything is OK with the engine.
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
ArizonaBOSS said:
BOSS 302S manual says change them every 6 hours of track time. I've been changing them every 6 months or so...which is a lot more. I'm starting to change them more often as the car definitely idled smoother with the new plugs after the last change. Plus you can read the plugs to make sure everything is OK with the engine.
Okay, lets see....how many track days where I only get one or two sets of laps is that?
LOL.
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
ArizonaBOSS said:
Plus you can read the plugs to make sure everything is OK with the engine.
Judging by the color of the plug I took out I'd say the inside of the engine is black. LOL.
Too much idling and low speed chugging around the shop I imagine.


This thing must need to be floored...and often!
I'll try to address that Saturday. ;)
 

Fabman

Dances with Racecars
6,519
8,154
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Grant 302 said:
Better the plug than anything else mentioned. Have fun at Laguna Seca!
That's what I was thinking too...thanks!
 
F.D. Sako said:
I have yet to change my plugs. It's got +40k miles and decent amount of track time. Maybe it's time!
It's time x4. ;)
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
Glad you sorted that out! You got me thinking about my plugs...on my second set in 31,000 miles. Any recommendations on the best plug??
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
I see the Boss 302S info says use

BR3E-12405-DA (Heat Range 1) or M-12405-M50 (Heat range 0)

Were as the Stock ones are Motorcraft SP548K?
 

TMO Supporting Vendors

Top