Help Question!! Car Misfires/Won't Idle

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Nov 1, 2005 | 09:22 AM

glhs422

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From: So. Cal

Help Question!! Car Misfires/Won't Idle

Hey All,
First off, I tried reading as much as I could before I posted this, but I couldn't find a DEFINITIVE answer as to what might be wrong.

The car is an '02 SS M6. 224/224 114 LSA cam, ported heads, long tube headers, ORY pipe.

The car ran perfectly until I started it up yesterday afternoon. It started up fine and drove normal for a few minutes, then it started to sound weird, like it was missing. It got worse and then started sounding like it was going to die at stoplights. I parked it and hoped it would clear up after the engine was started again.

A few hours later I came back out and tried to start it. It fired but then immediately died. Then, I had to open the throttle 1/2-3/4 of the way to get it to start and idle. Now it wouldn't stay idling at all. Just before I parked it, I started hearing ticking coming (hopefully) from the valvetrain.

I put pulled the codes with a predator and came up with

p0101 - maf circuit range/performance

and

p0300 - random/mulitiple cyl. misfire detected

Any ideas?

This car was professionally tuned last year, there were NO mods recently done to this car and it has run perfectly since the tune.

Any ideas?

Thanks in advance!!

Last edited by glhs422; Nov 3, 2005 at 09:54 PM.

Nov 1, 2005 | 09:36 AM

TAQuickness

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sounds like you need to swap the maf with one you know that works

Nov 1, 2005 | 09:39 AM

Race-Prep

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From: Just outside of Palm Springs Ca.

It could be a few different things, I would look into the injectors as they are the only real thing that can suddenly cause a misfire other than the coils most of the time. If you like you can check spark on each cylinder individually to make sure they are all working. Then you can try replacing the injectors if you can borrow some to swap in there just to try, sometimes that is a good quick way to find problems. If these don't work out, we would be happy to get it worked out for you, just give us a call and we can schedule a time for you to come in and we will get it worked out. We have dealt with many weird problems like this in the past.

-Bryan

Nov 1, 2005 | 09:40 AM

Race-Prep

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From: Just outside of Palm Springs Ca.

That COULD be the problem but it usually won't make it misfire like that very often.

-Bryan

Nov 1, 2005 | 11:49 AM

fast347

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From: Houston,Tx

my car had these two codes p0108map or baro signal to high and p0102 mass air flow circuit signal to low and it had the same problem car would die and sputterd. I found a blown engine fuse.

Nov 1, 2005 | 02:50 PM

glhs422

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From: So. Cal

As far as I can tell, all the fuses in the two boxes near the driver's side fender are all intact. Are there any other locations I should look for as far as fuses go?

From what I have read so far, the PCM Ign, PCM Bat, and Eng Sensor are the 3 most important fuses for the problems I'm having (idling problems and low-rpm stumbling with MAF error codes). Does that sound right?

Either way, those 3 fuses all look to be intact, although I haven't pulled them to hold them up to the light. I'm just kind of scared to mess with anything because the car ran *perfectly* before this started.

Is there any danger in pulling those 3 fuses? Will it reset the PCM if I pull them one at a time?

Sorry for the newbie questions, but I'd rather be safe than sorry right now . . .

Thanks!

Nov 3, 2005 | 09:49 PM

glhs422

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Does anyone have any ideas about how a valvetrain part failure could cause the car to throw a MAF code? Would it also cause problems with idling/low RPM operation?

It seems like a broken spring/lifter/bent pushrod would still allow the motor to start and run, although there would be a lot of ticking . . .

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Nov 4, 2005 | 04:07 PM

00'WS6Rocket

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From: Fort Worth, Texas

Have you put on a k&n filter lately or reoiled it? I know when I had my old car I reoiled my k&n filter and within a week it was like yours but I wasn't throwing codes. I think I had put too much oil on it and it gumed up the maf. Just an idea

Nov 19, 2005 | 02:44 PM

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glhs422

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From: So. Cal

Well, it ended up being a broken valvespring. Not sure why the problems idling and all that with the MAF codes, but it's fixed now!

Would a broken valvespring normally prevent the the car from idling?

Thanks for your help, guys!