Mechanics

LUMINA - RANDOM CYLINDER MISFIRE ONLY WHEN HOT

1999 All Other Makes All Other Models

I have a 1999 Lumina with 35,000 km. Bought in 2005 with 13,000 km so the car was not driven much. 3.1 litre engine.

When the car is hot usually after 30 minutes of driving, it feels like it wants to stall when the accelerator is pressed. It backfires sometimes and juts feels like its not getting gas. When the accelerator is released it idles perfectly normal.

Changed the following : Plugs, wires Mass airflow sensor, ignition module, sent the computer out to get tested. The Catalytic converter melted as well, so that was removed and has stayed off for testing purposes. It is still doing the same thing now without the converter. I feel like I am just throwing away money. Any thoughts?
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Canchris7
December 13, 2006.



You can perform a compression test on all of the cylinders. A cylinder that have low compression can cause a misfire.

Tiny
Mathiaso
Dec 16, 2006.
Thanks for your reply. I thought of the compression, and while it's probably a good idea to do the test, I figured that if it wre a compression issue it would do it all the time, not just when its hot. Even when it is hot it's not doing it all the time. Last friday changed the crank position sensor as well, Ran two days it was fine this morning it did it again.

Chris

Tiny
Canchris7
Dec 18, 2006.