95 Bonny 3.8 series 2, fast idle and shudder

Hi all, I just bought my Granddaughter a 95 Bonny and the first time I test drove it nothing was wrong. The woman I got it from told me a sensor was acting up, but she couldn't remember which one. I picked it up and started driving it home today and all was fine at first. A bit later, maybe 5 miles I heard a ding and the car shuddered a bit and seemed to lack power and I noticed the check engine light was on. I stopped at the light and it was idling at about 1700 rpm. Wasn't idling that fast when I started off. Made it home and started searching online and found out it's a OBD 1.5. My sons scanner fits on there but it will not read the codes. His is an OBD2 scanner. Autozone and Advanced Auto can't check it either. I hate to start throwin parts at it, the mass airflow sensor is $130 and the Map sensor is $50. I'm going to gather up some sensors at the junkyard tomrrow and hope I find the right one. Anone else have this problem before?

there should be an idle speed sensor on throttle body ask at junk yard as to what it looks like. the only problem is junk yard sensors can have same problems

Never heard of that sensor, thanks, i'll give it a try and let you know.

Advance online lists it as fuel injection idle air control valve.There should be a way to read the codes using the amt of flashing of check eng light, but each veh is different as to getting the system to start thoses flashes, maybe someone at the autoparts store can tell you how its done on your veh. I dont want you to spend on wrong part.Oh and p/s the mass air flow can be cleaned there is a spray they sell but I use carb cleaner just dont hit with hard pressure that can break the wire it uses to read air flow.

Well, I ripped up the carpet and checked for the corroded wires and found none, everything looked tip-top. Checked and cleaned some ground points under the hood, same thing. I went to the junkyard and got a couple mass airflow sensors, a map sensor, an ambient temperature sensor and a throttle position sensor. Changed one at a time, same thing, idle going from 1100 to up over 3000. After doing that I went to Autozone and picked up a engine computer. That was it. Idles about 950 and the speedometer started working again! I patted myself on the back and had a beer. Hoped this helps someone else.

Glad you get the issue fix..

Pay attention to the idle speed and shift patterns for ques that the TPS may be getting tired..

Its common place for the PCM's on the 94-95 3800's to fail in odd ways..

All in all 95 was a really good year for the Bonneville... It was the lightest and quickest NA Bonneville made...:)

That Bonne cleaned up really nice. I got kind of attached to it. Really hated to give it to my Granddaughter. Hope her stolen Intrepid is found so I can get the Bonne back. And you're right, that car is pretty quick! Found out the dealer put in a NEW engine on1-3-07. Has less than 10K on it. Was told it's good in the snow by previous owner, any truth to that?

Mine has never seen snow...LOL.. Just Florida Rains..

Its a large FWD, with most of the mass on the front... I think its 65% on the front tires so it should get through the snow pretty decently..

I don't drive mine as much as I used to.. I might take it once in a blue moon and am always shocked how good it still gets around.. If it had a new motor with no miles on it I'd be tempted to want to keep it too...LOL