1985 riviera starts rough, runwith foot on gas, then stall if foot off of gas

Asked by Feb 01, 2015 at 08:21 AM about the 1985 Buick Riviera Coupe RWD

Question type: Maintenance & Repair

The Riviera ran fine. I had a squealing alternator belt and slipping power steering belt. I tightened the power steering belt and it still squealed so I replaced the alternator belt.  It stopped squealing and the car ran perfect. the next morning I went to crank it up and it took a few times to get it running while feathering the gas pedal. It had black smoke and a very rich smell of gas coming out of the exhaust. when I released the pedal it stalled and ( with the air cleaner off) it shot gas up into the air. I was able to jump out the computer (A & B ) and it gave me a #24 code which it says is the vehicle speed sensor, but the car wasn't in motion so I needed to check the connectors at the ECM or its the throttle position sensor adjustment. I replaced all of the vacuum lines a few months back and I followed all lines to see if anything was disconnected but everything looks good.  I was wondering if anyone might know if there is anything else to check before I start going into the carb. I have reset the computer also. I was wondering if the tps may have gone bad or any sensors that could go bad that might cause the regulation to go bad or maybe the float has stuck in the bowl of the carb. Thanks very much in advance to anyone that might give me a few suggestions or send me in the right direction.

4 Answers


I assume you have the 8 cyl. I owned a 85 Riviera and was experiencing similar problems. Black smoke is an indication of a rich burning and to check the carb is a good start. But what's concerning is the gas shooting out the carb. indicating a stoppage. I discovered very little exhaust was leaving the tail pipe so I removed the catalytic converter.

1 of 1 people found this helpful.

Hello Mark, It is the 307 V8 motor. I have lots of smoke from the exhaust. I will go into the carb and see if I can find a blockage or a faulty float. Thanks a lot for your input.


You're clogged. Simply put


Hello, 85riviera where you able to resolve the problem, if so please share with us.

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