Hi,
I have a new issue.After I changed my Cam Shaft Sensor, my check engine light went off & vehicle was starting normally.
Yesterday I started my AC & suddenly for a moment I lost compression & the check engine light came up & stayed until I stopped the Car. After restarting there was no check engine light . But then everytime I am starting the AC , the vehicle is loosing compression for a moment & the check engine light is coming on.
Can you please suggest me what is happening & how I can fix this
Thanks
Starting AC brings the Check Engine light
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mmechanical
- SLE Member

- Posts: 25
- Joined: Tue Jun 03, 2008 10:12 pm
- Year and Trim: 1995 SLE
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Arriva
- SE Member

- Posts: 17
- Joined: Thu Sep 18, 2008 9:07 am
- Year and Trim: 1996 Bonneville SE
- Location: New Baltimore, MI
Re: Starting AC brings the Check Engine light
Just a thought - could what you are saying is "lost compression" - being caused whent the A/C compressor mag clutch engages?? This could mean the magnetic clutch is going bad or the compressor is getting ready to lock up. Have some one sit in the car while you stand to the passenger/left side of the car where you can observe the A/C compressor, have them start the A/C and you check to see if the engine pulls down at this moment the mag clutch engages. If you determine the problem is the A/C compressor and or mag clutch (located on the front of the compressor) fix it before it locks up and leaves you stranded - it will break the serpintine fan belt leaving you with no power steering, no charging but immediately worse no engine cooling. . . good luck.
- RJolly87
- Certified Bonneville Nut

- Posts: 5403
- Joined: Tue May 27, 2008 8:53 am
- Year and Trim: 1993 Buick Park Avenue
1994 Buick Regal Custom - Location: Las Cruces, NM
Re: Starting AC brings the Check Engine light
I think it would be best to get a code scan at this point, to see which code is being set. I would think it would be stored. That would possibly give you a place to start.
~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place
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mmechanical
- SLE Member

- Posts: 25
- Joined: Tue Jun 03, 2008 10:12 pm
- Year and Trim: 1995 SLE
Re: Starting AC brings the Check Engine light
Let me start from the History of the issue...
Before Couple of weeks, I got problems starting the vehicle .It was getting started when cold but It was giving the check engine light . I got a scan done and it was indicating towards Cam Shaft Sensor.
I replaced it my self & then my Bonnie started as normally..
http://www.pontiacbonnevilleclub.com/fo ... 89#p138389
Till Tuesday it was good.
Then I started AC & the check engine light came up .. From today the engine is not getting started even.
Dont know what I should do......
Before Couple of weeks, I got problems starting the vehicle .It was getting started when cold but It was giving the check engine light . I got a scan done and it was indicating towards Cam Shaft Sensor.
I replaced it my self & then my Bonnie started as normally..
http://www.pontiacbonnevilleclub.com/fo ... 89#p138389
Till Tuesday it was good.
Then I started AC & the check engine light came up .. From today the engine is not getting started even.
Dont know what I should do......
- Echo SSEI
- Retired Gearhead

- Posts: 2960
- Joined: Mon May 19, 2008 11:31 pm
- Year and Trim: 1997 SSEi
1993 SSE - Location: Phoenix, Arizona WCBF '05, '06, '07, '08 - NEBF '07
Re: Starting AC brings the Check Engine light
This ia rather odd. Never heard of the car having a misfire when the compresor kicks on. Best place to start would be to check to see if there is a new code set, so we get pointed in the right direction. Don't need to start the car to see if there is a code set, assuming you have a scanner or someone with a scanner can come to you.
"Really Not Stock Anymore" Bob and most recently renamed, "Chief BadLifter" 
Best ¼ ET=13.674, Best 60’=2.122, Best Trap=102.26 mph Pacesetter headers (2.5" outlet), Magnaflow hi-flo cat, INTENSE FWI w/K&N 9" cone, ZZP XP cam, INTENSE OR pushrods, Comp 105 springs, Autolite 103 plugs, Stoppenbach tuned PCM
SingsCountry1967 wrote:I can babysit your car for the week... or rent it.... I won't race it I swear <fingers crossed>

Best ¼ ET=13.674, Best 60’=2.122, Best Trap=102.26 mph Pacesetter headers (2.5" outlet), Magnaflow hi-flo cat, INTENSE FWI w/K&N 9" cone, ZZP XP cam, INTENSE OR pushrods, Comp 105 springs, Autolite 103 plugs, Stoppenbach tuned PCM

