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Discussion Starter · #1 ·
I am at an autocross. The exhaust is emitting some black smoke at the tail pipe; so, it’s clear the car is running rich. I parked for lunch and when I went to restart for the afternoon session, the car gave a big puff of black smoke on start-up, started running rough, and the CEL came on (solid, not flashing). I don’t have a code reader with me and will check codes this evening. Seems like a vacuum leak or MAF. Seems to smooth out off of idle, but still smokes. Checked for vacuum leaks. Don’t see anything obvious.

I’ll circle back once I pull codes, but I was wondering if anybody had any ideas so I could c]get back to racing…

—Bill
 

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Always carry a reader with you. They weigh nothing. I would check your O2 connections and wiring along with MAF for starters without codes to go by.
 
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Could be MAF but you can easily check that by disconnecting the MAF connector and see if anything changes. It could also be a malfunctioning injector, a dying spark plug or coil or a bunch of other bigger issues.
 

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I have had a coil fail. Does strange things at strange times
 

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Discussion Starter · #5 ·
Well, I got the car home under its own power. Ran fine, actually, although the CEL was still on. I pulled the codes: P0304 (Cylinder 4 Misfire Detected); P1301 (Cylinder 1 Misfire Detected); P1302 (Cylinder 2 Misfire Detected). Cylinder 1 and 4 misfires were recorded as "permanent," whatever that means. Anyway, I cleared the codes. I have not driven it again, but I suspect something is failing.

So, I misfire would certainly explain the rich condition and the rough running. More likely that the cylinder wasn't firing at all. But which cylinder? I guess I'll pull all the coils and check them. It's been while since I've done that. I recall a resistance check between two of the contacts. Anybody know the specifics for these coils? And how hard are the coils to get to? I'm guessing the supercharger has to move.

Any additional advice? Meanwhile, I'll do some research.

--bb
 

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Looks like you’re getting misfires on both banks. You can pull the coil packs/plugs like you mentioned, but also check the plugs and make sure non are loose or that any of the wires/insulation have been mechanically damaged to those cylinders.
 

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Discussion Starter · #9 ·
I think I have another data point to add. I took three runs in Sport mode. Then I tried it with Sport mode off (thinking the throttle response would be less aggressive and make the car easier to drive) and made three more runs. That's when the car went haywire and started running rich...this was all before the CEL came on.

Anyway, I have not driven the car since I got home from the autocross and cleared the codes. I'll report back what I find.

--bb
 
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