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Old 12-09-2007, 12:28 AM   #1
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Default Weird pop before start up

There was a thread about this a couple of months ago. Couldn't find it, but it happened to me this evening. Cold start, put the car in nuetral and lowered the e-brake. Turned the key to Ignition2 ON, but not all the way to start. I always double check to make sure the car is out of gear because I'm running the clutch lockout override. Right after I turned the key to IGN2, there was an ignition event of some sort. Sounded like a backfire. Actually it sounded kind of cool through the duals. Turned the ignition off again, and then back to IGN2 and there was no drama, so I started the car. She ran like *** for about 45 seconds. Felt like 2 cylinders, but as soon as I opened the hood, it cleared right up and ran on all 4. Got in the car and drove off, and after arriving at my destination, the car sat until cold. There was no further drama at the cold start to come home, and all is fine again.

On rare occasions, there must be a ignition event when the MS boots up, and once in a blue moon, I suppose that ignition event meets the random vaporized fuel.
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Old 12-09-2007, 12:33 AM   #2
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Mine used to do it all the time, I have prime pulse set to after 2 sec now though and it doesnt happen anymore. If you have prime pump set to power up or twice then it will happen to you because the ms sends a spark signal when you turn the key to on.

This is my understanding at least.
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Old 12-09-2007, 12:55 AM   #3
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That's my understanding as well, i was getting it when i had a super rich idle. The MS must fire the coils when you power up. I've heard of some people that have had the backfire go off and blow vacuum hoses off their intake manifold. Neo's 2 sec idea could be a good way to cure it.
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Old 12-09-2007, 05:38 AM   #4
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ben i get the same exact thing occasionally. The first time i **** my pants when it happened lol
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Old 12-09-2007, 06:03 AM   #5
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Ben, I had the EXACT same issue. Ran like *** for about a minute and then ran fine for the rest of the day. Try the 2 second prime pulse. You also may be a bit rich on your start enrichments.
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Old 12-09-2007, 11:27 AM   #6
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Good to know. Like I said, that was my virginal pop. If anything, my CSE is lean. Definitely not rich.
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Old 12-09-2007, 02:23 PM   #7
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leaky injector maybe?
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Old 12-09-2007, 02:36 PM   #8
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mine started doing it when it was colder and i didnt have my cranking PWs tuned.
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