My 1995 Buick Riviera ultra sc. With 144k.
Revving the engine with my foot stopped at about 4krpms , the engine revs up and down until I take my foot off the pedal.
- What can I do. I've already changed plugs and put a new coupler in sc (runs great)
Well one you're not supposed to rev the engine up that high if you're just sitting at revving it up all modern American cars have a setup that once you reach high revs it will deliberately just rev up and down it's a safety thing to keep you from blown engine. If a car runs okay otherwise down the road stop revving it up and down when it's just sitting there
Thank you very much
Hey Riviera Man, Hello from California. '95 is definitely pushing it, I was born in '92 (best year) myself. For just about any make/model you should be looking at an rpm range of 0.6 to maybe 1.3k rpms at idle. Maybe I am misunderstanding your symptom here to begin with. So when you're just doing regular driving does your car seem to stall out at stop signs? Is this why you are pressing some on the gas pedal to keep it going? For that age you may be looking at a vacuum seal leak. Intake gaskets and seals can only withstand so many heating and cooling cycles before they start to wear and cause a high idle surge with the extra pockets of air coming in. Besides that the mechanism that handles the idle air control can wear also over time and present similar symptoms.
It drives great, I was saying that while I have my foot on the accelerator holding it down in my driveway just checking it out. The engine revs up and down on its own while my foot stays at the same position that it was when I took it up to, about 3.5krpms
Just got answer from scotty and he told me that American cars are made that way so you don't blow the engine up