1994 Buick L67 3800cc Supercharged Sensor issue
 

I have a 94 Park Avenue with the L67 engine that is running roughly between about 1700 and 2200 RPM. I live at 4K feet elevation but when I drive to to a lower elevation, > 1k, it does not do this, but when returning back up the hill, it starts in again at about 3k feet.

A few months ago I had this problem and took in to my local mechanic to check it out. He's very good, but works from his home garage and doesn't have all the bells and whistles that a full blown commercial shop would. When we ran an analyzer it said the MAP sensor was failing, but after searching the internet for a diagram of the L67 we couldn't find one, and the diagrams we did find online that looked similar to my engine had nothing in the indicated locations for the sensor we had purchased from a nationally known auto parts chain. He recommended that I take it to a commercial shop and pay the usual hefty fee to have them analyze it. Fortunately, it stopped having the problem the next day when I drove it, which was good because funds have been tight lately due to my wife's health issues.

However, it started acting up again about two weeks ago, and I need to resolve this as quickly and as cheaply as possible.

So my first question is does this sound like a MAP sensor issue, given the different behaviors at different altitudes?

Second, can someone PLEASE provide a link to a diagram of the L67 engine so I can where the MAP sensoris ? The car has 122k miles on it, and the sensor is relatively inexpensive so I figure it couldn't hurt to replace it so I can eliminate it as a possible source of the problem. I am usually hell on wheels when it comes to finding things through Google, but I've just spent well over an hour looking for an L67 diagram and have had zero success.

Thanks in advance for your help.

That is a series I engine.....I know on a Series II(starting in '96), it was in the back middle of the engine near the top.....