Engine RPM drops right after starting unless I give it gas
The engine's RPM falls below 500 immediately upon starting, forcing you to apply the throttle to keep the car running. Once the engine warms up and becomes heat-soaked, it loses power, backfires, and suffers from single-digit gas mileage. This condition triggers lean and rich error codes, often prompting owners to replace the O2 sensor.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1giving it gas nearly immediately after startingDid this help you?
- 2Replacing oxygen sensors based on OBD codesDid this help you?
- 3Unplugging the MAF sensor to see if the engine diesDid this help you?
- 4Checking for vacuum leaks by spraying starter fluid around the intakeDid this help you?
- 5Inspecting the pickup coil inside the distributorDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Recently when trying to start my NB2 miata (1.8L I4) I have to give it gas nearly immediately after I start it because it drops to <500 rpm otherwise.”source ↗
“Loss of engine power once heat soaked with no hard starting issue.”source ↗
“Changed o2 sensor due to lean and rich codes being thrown.”source ↗
“Unfortunately i dont have a electro-digital gauge to test sensors.”source ↗
“Edit: also backfires once warm. Lean pops?”source ↗
“Mpg is junk. It's been single digits for awhile.”source ↗
Where this came up
People with this problem also raised
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- 3Why does my truck make a rattling noise after I turn it off?
- 22Why does my car lose power when I step on the gas?