Hello, I've been chasing a surging condition in my 71 Olds cutlass for some time now. The engine is a Rocket 350 2brl. This is a low mileage engine that remains completely stock. It has been tuned up with everything being set to factory service manual specs. Also the carbureter has been rebuilt and the fuel pump has been replaced. The engine has a surge under light throttle when cruising. There is no hesitation off the line and and no surge or hesitation under moderate or heavy throttle, just under light throttle. Any ideas? Thanks, Dave
At light throttle and cruising your carb is running as lean as possible.
Adding any extra air at this time can cause a surge.I would clamp off every vacuum line running to the carb and manifold a take it for a drive.Remember without the power brake vacuum the brakes will be very hard to push.If it runs without a surge unclamp one vacuum line at a time while driving inbetween unclampings until you hit the vacuum line which causes the surge.Now you can trouble shoot that line.I assume you have a new gasket between the carb and manifold.Does the distributor vacuum advance hold a vacuum?
Check for vacume leaks. Hoses and around intake gaskets.spray some carb cleaner around intake gaskets.
SOURCE: olds alero 2.4 idle fuel pressure
most likely idle air control sensor or low engine coolant I know sounds funny but IAC uses coolant to regulate idle. Idle air control valve or throttle body positioning sensor.
SOURCE: 1971 Olds Cutlass Supreme. Dash brake light stays
They are unrelated. Just make sure your brake release is fully relesed. The switch turns the light on if the release isn't against it fully.
SOURCE: '98 Oldsmobile Silhouette-begins to surge at 2500
how about the sparkplugs and the wires, you may need to tune it up, sounds like it misfires under a load, i would start with a tuneup and go from there. the other thing that come to mind could be a bad coil pack, or low fuel presusre,if you have the computer scanned and pin point the cylinder or cylinders misfiring you could try switching coil packs or plug wires to see if the misfire move and if it does you would know if its a wire coil or plug, but if its been a while sence you had a tune up i would start with that.
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I have the same problem except my car is a 1985 oldsmobile delta 88 307 4bll carb. Ive replaced the Thermastat,air filter, fuel filter, flushed the radiator, transmission filter, spark plugs and wirers, and when the engine gets hot after 8miles it starts ping and surging and lack of power.
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