# Two out of four

**URL:** <https://community.cartalk.com/t/two-out-of-four/38556>\
**Category:** The Show\
**Tags:** chevrolet, lumina\
**Created:** [October 24, 2009, 4:17pm UTC](https://community.cartalk.com/t/two-out-of-four/38556 "2009-10-24T16:17:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![swi8453](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@swi8453](https://community.cartalk.com/u/swi8453)\
**Post date:** [October 24, 2009, 4:17pm UTC](https://community.cartalk.com/t/two-out-of-four/38556/1 "2009-10-24T16:17:41Z")

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I replaced the ecm and the sencoir that contrals the spark. I also replaced the coils, the spark plugs, and wires. the car starts however it is only running on the first and second cylinders is this a timing chain issue or is thier another spark controling device?

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**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\
**Post date:** [October 24, 2009, 9:32pm UTC](https://community.cartalk.com/t/two-out-of-four/38556/2 "2009-10-24T21:32:19Z")

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You need to do more testing and less part changing.

A compression test will reveal condition of the chain and valves.  
Test for spark at each plug.

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**Author:** ![Caller\_X](https://avatars.discourse-cdn.com/v4/letter/c/8797f3/32.png) [@Caller\_X](https://community.cartalk.com/u/Caller_X)\
**Post date:** [October 30, 2009, 3:34pm UTC](https://community.cartalk.com/t/two-out-of-four/38556/3 "2009-10-30T15:34:11Z")

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Did you hook up the cables between the plugs and distributor exactly as they were before? Best practice is to do one at a time.