Intermittent cold running problem; now constant; coil pack?

[j_eclipse96]

So since winter started, my car had a problem running when cold until it heats up - it will miss a few times when getting on the throttle, then decide to go.. as soon as it heats up though, the problem disappeared.

But when I came out from work today, I started my car, and it refused to rev, and was obviously running rich. I waited until it warmed up, thinking it would be fine like normal, but even after the temp gauge was reading normal, it continued refusing to accept throttle. But it idled fine, exactly like it did before.

I popped my hood to take a quick look at everything, and noticed sparks coming from around my coil pack and under it, especially under load when I feathered the throttle body. I know you're thinking bad plug wires, but they are literally two month old Accel wires, and I had no stuttering before in the top RPM range like I did before replacing them. I then tried fiddling with my fuel settings on my GM MAFT Gen2 to no avail.

tl;dr version: Could a coil pack going south cause problems running only when cold until it went out completely?

Thanks guys. And any ideas are more than welcome.

 

[asexton6969]

Yea sounds like the coil pack is malfunctioning. Ive seen on other cars where the coil pack seperates and as the engine warmed up it caused the plastic on the coil pack to expand and it would stop grounding out. Quite entirely possible.

 

[j_eclipse96]

Threw in a used coil pack, and the arc disappeared, but the problem remains. Still can't give it any throttle without it wanting to die. Threw a new set of plugs in; no change. Unplugged my GM MAF and noticed I could give it gas without it dying, although it runs like crap, but can drive. MAFT Gen2 settings are back at default after trying rich and lean settings to no avail.

Finally got my logger working:

CEL Read p0100, which wasn't in my pocketlogger database (I think it was from when I unplugged my MAF), and p0510, which is the closed throttle position switch. Its been throwing the p0510 for a long time now.

CTS is good, reads right where it should be on my logger.

Timing, on the other hand, gave me an odd reading on my logger (I know thats not how you check it, but bare with me). When I revved my engine the best I could, the timing stuck right with it from 9 at idle to around 27 at 2000 rpm, solid with no bouncing around. Isn't it only supposed to do this in closed loop? It was still cold, so maybe thats why.

O2 voltage was also very low when I hit the throttle, around zero constantly. This is rich, correct?

Airflow readings were strange as well, very slow to change and respond to throttle. Also sometimes sticks in one spot. Generally was around .30.

Also, I have noticed some ticking, almost sounds like arcing, coming from around the top of my valve cover towards the injectors (not lifter tick), which goes away when the MAF is unplugged.

Sorry for the long post. Just trying to give you guys as much info as possible. Anything else I should check?

 

[npysp33dmami7]

you should just change over to NGK plugs(copper) and wires. make sure your MAF is plugged all the way in as well, mine was working it's way loose and my car barely ran. Also, check your plug gap .28 my gap was way off it moved on it's own from the heat to about .45 which made my car run like crap, it made it miss and everything. also check for vacuum leaks

 

[j_eclipse96]

you should just change over to NGK plugs(copper) and wires. make sure your MAF is plugged all the way in as well, mine was working it's way loose and my car barely ran. Also, check your plug gap .28 my gap was way off it moved on it's own from the heat to about .45 which made my car run like crap, it made it miss and everything. also check for vacuum leaks

Plugs are a brand new set of NGK bpr6es', gap is .28. Don't believe I have any vacuum leaks, as it would only be running this bad if one of the intercooler pipes was completely disconnected. This problem started as only when it was cold, then one day it did it constantly. Thanks for the ideas though.

 

[j_eclipse96]

Been doing some research, and I've read that coolant temp sensors can be bad but still send proper signals to the ECU. This would make sense, seeing as how this all started as a cold start only problem, and maybe the arcing was unrelated. Should I just try swapping in a new coolant sensor, and if that doesn't work, a different MAF?

 

[j_eclipse96]

Alright, update: I was again researching various subjects, and came across the power transistor, which I hadn't checked yet. I decide to look at it, and lo and behold, when I removed the wiring harness there was some sand and moisture on the weather gasket, as well as inside the power transistor plug itself. Both also had a nice curve going about them horizontally, which I imagine let the moisture in.

I busted out my Chilton's, and followed the procedure for testing it via continuity, and it tested good. But if there was moisture inside it, couldn't that cause it to arc on the outside, possibly to the 4-1 coil pack?

Again, thanks for the help guys.

 

[j_eclipse96]

Another update:

Swapped out my old GM MAF with a different one, no change. Still extremely lean at idle.

Figured it must be the o2 sensor, as I couldn't think of anything else that would make it read lean like this. Swapped in a new Denso direct fit o2 sensor, no change - still reading almost 0v at idle, and around .60 when revving.

I do have a slow coolant leak at the hose entrance next to my coolant cap, which I noticed dripped onto my harness for my o2 sensor... Could this possibly corrode to the point where it just reads weak voltage? Any way to test this?

Haven't touched the CTS yet since I'm getting lean readings, and a bad CTS would cause rich readings, I would assume.

I'm running out of ideas here, guys. Any help would be greatly appreciated.