Check Engine Light 93' Century V.6

[Enzolio]

Hi all, I have Buick Century 3300 engine V.6. I bought this car off Craigslist and its been running great except for idling. In the morning when I start it up it revs normal then it kicks in to higher rpm then the check engine light came on. After good warm up it goes away but when you drive it feels like your slightly stepping on the gas and holding the brake. It idle a bit rough but doesn't die and has full power.

I myself changed the air filter, fuel filter and PVC valve. I took it in and serviced a full tune-up, Complete Fuel Injection clean and they replaced some old vacuum hoses. It runs better but the check engine light still comes on when I first start in the morning. Repair shop said MAF sensor is still good and other sensors but I need to consider Idle Throttle Sensor may be at fault.

I've seen forums and posts about these early 90's cars having emissions issues. Is this common for Buicks? Can I replace the Idle Throttle Sensor myself? Any other common faults for these years engine 3300?

Thank you all!

[maxwedge]

Welcome to AF, have you checked for the cel code?

[Enzolio]

Hey MaxWedge,

thanks for replying. no, i havent checked the codes myself (amateur). I dont have a code scanner. I turned down the idle because it raced a bit but at mornings the check engine light kicks in but goes away. Firestone said when they ran the codes the Idle Throttle sensor came up.

I've worked on Mopar engines before and i wasnt told to unplug a cable line from the battery terminal when you change any sensor. It causes the check engine light to come on again. Im wondering if its the same case with GM's engine. i want to save my pocket from the repair shops and dealers and do it myself.

Thanks,

[maxwedge]

You can get the code by jumping the a and b terminals at the plug under the dash.and counting the flashes, do a google search or site search here for "checking obd1" codes. Not true about disconnecting the battery on that year. The idle speed control, or the throttle position sensor, the terminolgy you posted is wrong. If you turned the base idle set screw that is a factory setting and must not be altered.

[HotZ28]

Click Here for code retrieval procedure.