2000 Cadillac Deville Will not start when temp gets below

Tiny
CONVERTERKID2000
  • MEMBER
  • 2000 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 177,000 MILES
This car runs fine when the temp is above 32 degrees. When it gets colder it will crank but will not fire or start. Just cranks. Someone told me to check the coolant sensor. So one night when it was only -7 degrees I tried to start it. Nothing. So I poored hot water in to the coolant tank. It started right up. SO then I took the tank out and cleaned it. Decided to leave the sensor unhooked. The car started fine, but the dash said to check the coolant level. Left the sensor unhooked. Yesterday morning tried to start the car, just cranked. Took a wire and jumped the sensor plug, still didn't start. Unhooked the jumper wire and it started. Am I looking in the wrong place or does the sensor have to be hooked up for the car to run?
Do you
have the same problem?
Yes
No
Thursday, February 12th, 2009 AT 9:29 AM

6 Replies

Tiny
FACTORYJACK
  • EXPERT
You are dealing with the coolant level sensor that has nothing to do with starting. It is just coincidental that it starts sometimes, and not others. I would say, when it is cold and wont start, spray a little starting fluid in the throttle, see if it tries to start. Unless you have a fuel pressure gauge to hook up to it. You are either losing spark or fuel, it is a little easier to determine fuel first.
Was this
answer
helpful?
Yes
No
Friday, February 13th, 2009 AT 9:41 PM
Tiny
CONVERTERKID2000
  • MEMBER
Thanks gstacey! I'm going to try that this morning. This car has done this for 2 years. But only when it gets cold.
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 9:08 AM
Tiny
CONVERTERKID2000
  • MEMBER
Thanks gstacey! I'm going to try that this morning. This car has done this for 2 years. But only when it gets cold, [/quote:3631ad27d4] Took off air cleaner and used starting fluid. It tried to run. Going to take off the fuel filter and sheck pressure now. But why would it only act up when it is cold?
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 11:03 AM
Tiny
FACTORYJACK
  • EXPERT
You have a pressure test port on the fuel rail, no need to remove filter for check if you have the right fitting. If you have adequate pressure(40-45 psi), then it could be a temp concern. To validate this at first, a scan tool that is capable of reading data would be required. Although, if you disconnect the coolant temp sensor, open circuit reading to the ECM is -40. When it won't start, disconnect the coolant temp sensor, and see if it starts. The thought behind this, maybe it is not reading cold enough when it gets to the temps your experiencing. The coolant temp sensor is in the rear bank head(1, 3, 5, 7) at the trans end. If you look down below the master cylinder at the rear of the head, you will see a conduit that leads to some grounds on a stud. Just to the left of that ground stud is the ECT sensor(two wire YE/BK). Another concern might be some moisture in the fuel that is icing causing blockage or restriction. We don't typically have temperatures that low in our region, so I am just giving some ideas.
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 11:59 AM
Tiny
CONVERTERKID2000
  • MEMBER
Funny thing is if you put a battery charger on this car at the battery, put the charger on 200 amp after a little bit it will start. Then after it has been started it runs fine all day starts ok. Where is the fuel pump relay located at. Checked voltage at the pump connector only voltage at small connector. Don't hear the pump running either. Going to check the coolant sensor now. Thanks
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 12:27 PM
Tiny
CONVERTERKID2000
  • MEMBER
Funny thing is if you put a battery charger on this car at the battery, put the charger on 200 amp after a little bit it will start. Then after it has been started it runs fine all day starts ok. Where is the fuel pump relay located at. Checked voltage at the pump connector only voltage at small connector. Don't hear the pump running either. Going to check the coolant sensor now. Thanks[/quote:532a325f7a] Found the problem! It was the fuel pump relay. Thnks for the help will be sending a donationn a few days
Was this
answer
helpful?
Yes
No
Saturday, February 14th, 2009 AT 10:38 PM

Please login or register to post a reply.

Recommended Guides