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Bad Map Sensor?

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Old 01-23-2008, 12:27 PM
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Default Bad Map Sensor?

Just did the ls1 to and ls6 intake swap, got everything on ok. But now my MAP sensor is acting up. The engine was acting up, but I thought it just had to do with the car not acclimating to all the stuff I did to it at once. (headers, duals, !egr, !air, !rear o2s, ls6 intake)

I took it to get it tuned and the MAP reading was 92 across the boards, no variation. So we're assuming it's the sensor.

I've checked all the hoses and connections, and there aren't any vacuum leaks as far as I can tell. I was thinking about trying to swap the MAP sensor from my old ls1 intake onto the ls6 intake that's already on the car.

Can I get it out without breaking it?

Can I install it without having to take off the intake?

Any other suggestions or ideas?

Thanks in advance!

Jeff
Old 01-23-2008, 01:09 PM
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I know I couldent get the map sensor out with the intake on my car man its tight in thier and I'd be afraid of braking the new on even if I could get the old one out. haha but I'd probly try it once haha.

one thing to try unhook your battery take out your pcm fuse cleen your maf if you havent then do the idle relearn process, after u put everything back togather then put on your parking brake put it in drive for 5 min then in park for 5. just somthing simple to try firts its one thing I'd try anyway.
Old 01-23-2008, 02:13 PM
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If it's reading 92kPa then it's maybe popped out
or something. An electrical open would peg it to 0
or 105kPa. Are you seeing anything that might be a
1/4" diameter vacuum leak?
Old 01-23-2008, 06:18 PM
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Originally Posted by jimmyblue
If it's reading 92kPa then it's maybe popped out
or something. An electrical open would peg it to 0
or 105kPa. Are you seeing anything that might be a
1/4" diameter vacuum leak?
I felt around back there for a good 10 minutes trying to make sure there was nothing loose. As far as I can tell there isn't anything, but that's only as far as I can tell, so who knows. I'll try a mirror and a light before I start pulling anything apart just to be on the efficient side.

But you're saying that a steady 92kPa would indicate it's a vacuum leak and not an electrical issue, correct? Hmm...
Old 01-23-2008, 06:19 PM
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Originally Posted by BLACK2001SS
I know I couldent get the map sensor out with the intake on my car man its tight in thier and I'd be afraid of braking the new on even if I could get the old one out. haha but I'd probly try it once haha.

one thing to try unhook your battery take out your pcm fuse cleen your maf if you havent then do the idle relearn process, after u put everything back togather then put on your parking brake put it in drive for 5 min then in park for 5. just somthing simple to try firts its one thing I'd try anyway.
I definitely know what you mean about the tight space. Big hands and that small little area = PITA. Not to mention the needle sharp nipples GM decided to leave under my hood shroud are playing hell on my forearms.

Thanks for the advice, I'll give those a shot. Couldn't hurt. Anything's easier than having to completely pull the intake again.
Old 01-23-2008, 07:45 PM
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I mean 92kPa seems about right for high elevation
atmospheric pressure. You ought to see that when
the motor is not running but running, it must be less
(more vacuum) except WOT. If it doesn't move it's
not "seeing" manifold vacuum. But that number seems
like an unlikely one, to come from electrical faults so
thinking it's got to be a "pneumatic fault".

Now the brake booster hose shares that "nipple". Any
chance it's off there and leaving the MAP to see open
air?




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