I have notice a wierd thing with my boost gage lately. I have only noticed it at night when the dash lights are on. It will just all of a sudden get stuck on the middle of the gage at 0psi. Then if i give it slight throttle it pegs the needle to 10 psi. then after that it wiggles back an forth and iether gets stuck at the bottom -10psi or back at zero. After acouple cycles and couple minutes all is normal and the gage moves as it should with throttle. I checked all of the vaccum fittings, even removed them and checked them very closely and found no problems. just wondering if anyone has seen this before?

That it strange. Sounds like either your MAP sensor or the gauge itself it going. Just curious as to whether you checked the condition of the "T" under the */C snout? That one can be a bit hard to see, and the hose that leads to the back I believe goes to the MAP sensor.

Dick, that is correct, the vacum line leaves the "T" and terminates at the MAP sensor. Those particular vacum lines & the MAP are very obscure and diffucult to inspect closely.

Sorry I haven't responded sooner. I went out of town the day after I posted this. yup I checked all of the fittings pysically and with starting fluid. I replaced the entire vacum harness a few month ago so I am pretty sure that it is all good. The map sensor was my first thought as well. If it is the gage that requires a whole new cluster right? if so I'd just hook up an after market gage to monitor boost.
thanks

You may have other leaks..but try swapping the map sensors.. there should be two.. swapping the wiring and getting good readings would pinpoint if the sensor is bad.

Hey that'* a good idea! next chance I get thanks again.

Mine does this every once in a while. I think it is just a brain fart. It always clears up after a couple of starts.

I'm not following you on this one, Bill. There is only one MAP sensor. Or did I misunderstand what you posted. I agree though, he could swap the MAP out with another MAP as a troubleshooting measure.

according to my manual there is indeed two sensors but the hose only goes into one of them. from the picture i think they may both be contained in one unit. I'm gona go look now to see if I can tell.

EDIT: after looking it may say two sensors but there is only one box so either way I guess there is just one part to be replaced.