Title pretty much says it. When its COLD it surges while idling upon start up. It goes away once you start driving it and the engine warms up. Other than that it runs great. Its got about 235 K with a replacement motor that has about 100k. I’ve had it about a year. Great vehicle. Its a standard. Any thoughts?
Thanks,
Ed
Fuel delivery issue: IAC valve, engine temperature sensor, or fuel pump.
+1 to insightful’s post. With the added possibility of a vacuum leak.
When it warms up, it adds the O2 sensor signal to its metering variables, but until then it’s trying to meter fuel strictly based on the temp signal, the throttle position, the engine rpm, and the volume of air coming through the snorkel and/or the manifold absolute pressure. The oxygen sensor is compensating for the problem once the engine warms up and the ECU begins to use its signal.