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Map Sensor Plug

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Old Aug 10, 2015 | 07:39 PM
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Default Map Sensor Plug

Ive been chasing an idle problem for a long time and i wonder if finally i might of found something. I was trying to replace the rubber Y on the back of the manifold where there 3 vacuum lines connect. After i got that connected together i felt down to where the MAP sensor is mounted on a big plug on the back of the intake. I can grab that large plug and turn it back and forth a bit. It almost feels like it might unscrew but i didnt want to twist to hard before asking first. I was thinking maybe this is part of my issue as it will come and go at times. Will this just unscrew out of the back of the intake or is there a trick to it?
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Old Aug 11, 2015 | 12:46 PM
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I replaced the rubber gasket thing and the map sensor thinking it would help a weird idle problem I was having too, but it didn't. The sensor pulls strait up out of the hole once you move the little metal tab holding it down over a little. It is possible to do this without removing the intake. I had originally planned on removing the whole intake, but luckily I was able to fit my hand back there. I attached a picture of the old gasket compared to the new. I don't think the seal of the old gasket was compromised even though the fit was a little loose.

What idle problems are you having?
Attached Thumbnails Map Sensor Plug-map-sensor-new-old.jpg  
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Old Aug 11, 2015 | 06:50 PM
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Thank you for the pic and your explination i apprecieate that. When you had ahold of the MAP sensor was the large plug that screws into the back of the intake tight or would it twist a bit back and forth? Almost feeling like it might unscrew but it gets tight again.


Originally Posted by 5550racing
I replaced the rubber gasket thing and the map sensor thinking it would help a weird idle problem I was having too, but it didn't. The sensor pulls strait up out of the hole once you move the little metal tab holding it down over a little. It is possible to do this without removing the intake. I had originally planned on removing the whole intake, but luckily I was able to fit my hand back there. I attached a picture of the old gasket compared to the new. I don't think the seal of the old gasket was compromised even though the fit was a little loose.

What idle problems are you having?
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Old Aug 11, 2015 | 06:55 PM
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This entire piece that the MAP sensor mounts into.
Attached Thumbnails Map Sensor Plug-1428298111_f2f3f74189.jpg  
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Old Aug 12, 2015 | 12:34 AM
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It will start and might run fine for a few minutes then all the sudden it will begin reving up a bit at a time till it gets to about 2500 rpm then just hang there. Other times it will do it right the minute i start it up. Sometimes i can unhook the battery and hook it back up and it will act like it resets it and be fine. Other times that wont even work and i just have to let it set a few days then it will start up...but then shortly after begin to rev up. Ive replaced the IAC the TPS and even tried an entire different throttle body.
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Old Aug 12, 2015 | 03:09 AM
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Default Map Sensor Plug

Are you saying that the o-ring on the manifold plug (what that MAP sensor plugs into) is leaking...?
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Old Aug 12, 2015 | 12:45 PM
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Oh, I think I understand what you're saying now. On mine, the plastic thing that comes out of the intake, was solid as a rock; no movement. I don't think it should move or twist or anything. It's a press fit that only goes on one way. The intake should have a female key way cut into it and the plastic map sensor housing thing has the male end. It should only go in one way and not rotate from what I remember so I think something is def up with yours. It is possible to detach the big plastic thing from the intake, but you have to take a long *** flat head screw driver and go in from the throttle body side of the intake in order to press in the plastic tab. The plastic tab is what retains it to the intake. I wanna say there was another style GM used to mount the map sensor housing thing to the intake but I can't remember. Perhaps you have a different style than the one I am referring to. I would just pull the intake to see what's going on if you suspect this is your problem. New intake gaskets are like 20 something bucks.

You did the throttle position relearn procedure when you replaced the TPS, correct?
Attached Thumbnails Map Sensor Plug-map-sensor-housing.jpg  
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Old Aug 14, 2015 | 12:16 AM
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Now you understand what im up against. Its hard to explain it on here lol. Mine almost feels loose but i just cant twist it to pull it off. I think i will pull the intake like you mentioned and see. Probably be easier to do that than to try to get something long enough in there to trip the catch. My luck it would break the tab off and it would go in my motor.
Thank you for the help on it. I hope this is it.

Andy


Originally Posted by 5550racing
Oh, I think I understand what you're saying now. On mine, the plastic thing that comes out of the intake, was solid as a rock; no movement. I don't think it should move or twist or anything. It's a press fit that only goes on one way. The intake should have a female key way cut into it and the plastic map sensor housing thing has the male end. It should only go in one way and not rotate from what I remember so I think something is def up with yours. It is possible to detach the big plastic thing from the intake, but you have to take a long *** flat head screw driver and go in from the throttle body side of the intake in order to press in the plastic tab. The plastic tab is what retains it to the intake. I wanna say there was another style GM used to mount the map sensor housing thing to the intake but I can't remember. Perhaps you have a different style than the one I am referring to. I would just pull the intake to see what's going on if you suspect this is your problem. New intake gaskets are like 20 something bucks.

You did the throttle position relearn procedure when you replaced the TPS, correct?
Reply
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