Jake99SS

My car's been running rough for a few weeks and I decided to try and find out why tonight. It started running bad a while ago and I thought it was because of my header collector leak. Speed, Inc. put in a new O2 sensor for me to keep me running while we wait on a new header. I haven't had any issues with that so far.

The car runs "ok" for a little while then I start to feel a misfire creep in that gets worse and worse as I drive it. It's not as noticeable cruising but when I get into the throttle it gets a lot worse. P0357 keeps ocming back and it's description is "Ignition Coil G Primary/Secondary Circuit Malfunction." I ***-u-me this means coil #7 is dead or dying. Tonight I swapped the #5 and #7 coils. I cleared the code out and went for a drive for about 45 minutes. Checked codes again and it still reads P0357. If it were a dead coil, it woulda changed to P0355 right? What else could it be? Will a bad plug wire show up as a bad coil? Maybe the harness on the coil bracket has a bad wire in it?

wrencher

iTrader: (2)

I would check all the wires/terminals going to the coil & the bank's harness for any poor/loose connections. Sometimes the terminals loosen up & give a poor connection. You can carfully crip the female ends with a pin to regain some lost tension is necessary. If you look at the terminal end you'll see what I mean.
Another possibility is the PCM you may have a weak driver that is unable to activate that coil hot, that will take a little more in depth diagnois.

Jake99SS

Just to make sure I didn't have a brain fart, "G" or #7 is the rearmost cylinder on the driver's side right?

I'll check the wires and connections tomorrow. I hadn't thought of a problem with the PCM. I'm kinda leaning away from that as it ran great for a couple weeks after I replaced a valvespring and Speed, Inc. put in a new O2 sensor. This seems like something that just happened. How would I diagnose that?

wrencher

iTrader: (2)

#7 is the rear most cylinder drivers side. Was it apart for spring repairs? Maybe thats the deal. The PCM diagoistics are always involved, when I do them it's a lap top, a scanner & a digital storage osilliscope & then wait for the failure to occur = big fun!

DaddySS

It sets the code because it senses an open or short going to the coil, check the wiring carefully.

Jake99SS

I had a broken #3 exhaust spring. I swapped that but the car still ran badly. You can tell by listening that there's a bad exhaust leak somewhere up front. I will check the wiring today.

Jake99SS

Here's an update. I swapped the B1 and B2 coil assemblies. All four coils, harness, plug wires, and mounting bracket from B1 went to B2 and everything from B2 over to B1. I'm still setting P0357.

It ran fine for about a 1/2 hour out driving around. Seemed a lot smoother than before, accelerates and cruises good. I kept checking for codes in Autotap the entire time. Nothing was coming up so I closed Autotap and restarted it. Once it connected everything my idle dropped to 700 from 800 and it started misfiring. Checked the codes and once again I got P0357. Cleared it and it kept coming back.

It seems like if it sits for a while it'll run fine it's first time out with no codes. Then, once it recognizes codes on its own, or Autotap finds codes, then it starts running shitty.

With it idling, I pulled the #7 plug wire off the plug, it's getting spark and as expected it revs badly with that wire disconnected. I tried the same thing on #5 and got the same result. Shakes at the initial blip of the throttle. I'm at a loss now. I guess it has to be in the harness leading up to the coil assembly on that side of the engine?

Jake99SS

Don't everyone raise your hand at once...

Jake99SS

TTT for another update:

I took the car to a dealer to get everything checked out. I just got a call from them and they say it looks like the PCM is shot, it keeps losing #7 for no reason. I got pretty lucky, it's under the 8yr/80,000 warranty. Otherwise it'd cost me almost $900 parts & labor. They're double checking the wires to make sure but it looks like the PCM. I lose all my programming but I found out Jim at Speed, Inc. has my file so they just have to reload that. Sweet!

I drove the T1 cam on a stock program for almost 3 years so that shouldn't be a problem getting it over there. My only concern is the AIR, EGR, and post-cat O2 sensor deletes. Is the car going to go into limp mode if I try and drive it without all that stuff on there?

wrencher

iTrader: (2)

The car will run OK it will set some codes until you get it re-flashed. It should be no problem driving it there.

Jake99SS

I got it back last night. I did get codes for P0300, EGR, and AIR but it ran fine. I definitely need the program back in it though, mainly because of the fan settings. It's hitting 217 degrees sometimes. I hope this takes care of it, I'm *this* close to selling it.

Jake99SS

Well that damn P0357 code came back today. AFTER they replaced the PCM. It started its old tricks at lunch with the hesitation under throttle. Autotap shows a few misfires at idle from the T1 but they're gone by 1200-1300 rpm.

Where do the wires that run down the passenger-side strut tower go? They're the ones that pass *right by* the header. I felt down those today and found a couple of hard, flat spots. Coincidentally they're right where a couple of the primaries run past.

wrencher

iTrader: (2)

Those wires are for the starter the low oil level sensor & the crankshaft position sensor. I would think you'd have a ton of problems if that was damaged. It has to be in the harness somewhere.

Jake99SS

The dealer found the wires that were screwed up. It was done on Friday but I didn't have a chance to pick it up. The tech said the wires for the ABS and ASR sensors were a little chafed so he fixed those too.

Hawkeye

iTrader: (4)

Having the same exact problem as you.... where were the wires chaffing? I have been going through this for months and I was about to change the PCM too!....