Hello, I was replacing the upper radiator hose and doing a coolant change on my 1997 Lexus ES300. The car just hit 117,000 miles with no CEL. When I was bleeding air from the coolant, I had my foot on the gas at about 3000 RPM for several minutes to warm things up. At some time when the engine was running at operating temperature, the engine surged once every second. RPM's went down maybe about 200 RPM's every surge, but it kept that up until I eased off the accelerator. When I brought it back to 3000 RPM, it runs fine then does the same thing shortly after. Any ideas? Car runs fine 99% of the time.
Under normal idling:
- Coolant temp: ~194F
- FuelSys1: CL
- FuelSys2: CL
When it surges:
- Coolant temp: ~194F
- FuelSys1: OL-Drive
- FuelSys2: OL-Drive
Well those cars aren't made for sitting there idling high not moving. It runs fine otherwise I would just ignore it. But if it does it when you're actually driving down the road. Yeah then you got a problem. Like maybe the fuel filter is clogged or the pump's getting weak
