# '97 Chevy Truck only starts when it is warm **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [March 3, 2008, 8:50pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408 "2008-03-03T20:50:26Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![lotus78](https://avatars.discourse-cdn.com/v4/letter/l/278dde/32.png) [@lotus78](https://community.cartalk.com/u/lotus78)\ **Post date:** [March 3, 2008, 8:50pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/1 "2008-03-03T20:50:26Z")
I have a '97 Chevy Silverado 350 V8 that will not start if it is below say 25 degrees. It will fire on one or two cylinders but won’t run. Starts fine when it is warmer. Does this vehicle has some kind of choke that is not working? ---
**Author:** ![researcher](https://avatars.discourse-cdn.com/v4/letter/r/edb3f5/32.png) [@researcher](https://community.cartalk.com/u/researcher)\ **Post date:** [March 3, 2008, 9:47pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/2 "2008-03-03T21:47:55Z")
The choke function is taken over by the Engine Coolant Temperature sensor in conjunction with the PCU. The PCU determines how much fuel to inject on start according to the reading of the ECT. This sensor is separate from the sensor for the temperature gauge or light. The usual drill is to replace it rather that measure its resistance to see if its calibration is correct. It is also possible that the lead to this sensor is shorted to ground or that there is a problem in the PCU. ---
**Author:** ![lotus78](https://avatars.discourse-cdn.com/v4/letter/l/278dde/32.png) [@lotus78](https://community.cartalk.com/u/lotus78)\ **Post date:** [March 3, 2008, 10:32pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/3 "2008-03-03T22:32:13Z")
Thanks. Where would I look for the ECT sensor? I have not invested in a manual for this vehicle yet. ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [March 4, 2008, 12:20am UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/4 "2008-03-04T00:20:39Z")
Look here for coolant temperature sensor: [http://www.autozone.com/R,LOC2048/shopping/locsSelect.htm](http://www.autozone.com/R,LOC2048/shopping/locsSelect.htm) ---
**Author:** ![lotus78](https://avatars.discourse-cdn.com/v4/letter/l/278dde/32.png) [@lotus78](https://community.cartalk.com/u/lotus78)\ **Post date:** [March 4, 2008, 3:16pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/5 "2008-03-04T15:16:56Z")
Cool! Thanks. I have bookmarked this site. ---
**Author:** ![lotus78](https://avatars.discourse-cdn.com/v4/letter/l/278dde/32.png) [@lotus78](https://community.cartalk.com/u/lotus78)\ **Post date:** [March 4, 2008, 5:45pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/6 "2008-03-04T17:45:58Z")
Found it. I will let you know if this works. I have some auto repair queued up for the weekend. Of course I will need colder weather again for a real test. Guess I can compare the resistance values when I get the new part. Maybe I’ll put them both in the freezer for a comparison. Thanks all. ---
**Author:** ![kendan](https://avatars.discourse-cdn.com/v4/letter/k/bb73d2/32.png) [@kendan](https://community.cartalk.com/u/kendan)\ **Post date:** [March 4, 2008, 8:55pm UTC](https://community.cartalk.com/t/97-chevy-truck-only-starts-when-it-is-warm/11408/7 "2008-03-04T20:55:43Z")
You may also need to check the plugs. Old plugs have a bigger gap due to wear and when the temp is real low, your battery doesn’t put out as much juice. Subsequently, the spark won’t jump the gap. Just another aveune to check.