Cold mornings no start

2001 GMC JIMMY
180,000 MILES • 4.3L • V6 • 4WD • AUTOMATIC
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NATE3222
  • MEMBER
  • 1 POST
I've had no problems with it starting before. This is my first winter with the Jimmy. I thought it might have been the cap and rotor on the distributor. So I ended up replacing them. Now when I try to start it, it is backfiring into the carburetor. Any idea what might be causing that? Did I mess up when I replaced the cap and rotor? I'm pretty sure the plug wires are back on to that cap correctly. When I replaced the rotor an cap I took the old rotor off an put the new one on. Is there a certain way of doing that? I didn't make sure number one cylinder was TDC is that where I messed up or what? Any help will be appreciated an thanks in advance.
Dec 9, 2019 at 5:43 PM
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MOTOR MASTER
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 279 POSTS
Hello my name is Dave.

The best place to start is to insure you did get the wires back in the proper order. I have attached a illustration showing the firing order for your truck. If you find that you did switch a wire or 2 and you can get it started but still have cold start problems then the most likely problem will be a run lean condition since the colder the temp outside the more fuel is needed for the engine to run. There are a few possibilities that could cause this but I would start with the fuel filter if it hasn't been replaced recently, the other thing I would check would be the coolant sensor since if it is not reading correctly and is telling the computer that the temperature is higher than it actually is. Let us know what you find with the firing order and the fuel filter and also if you have a check engine light on, if it is on here is a link to our tutorial on how to retrieve the trouble codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

If it is the coolant temperature sensor it will usually have a trouble code for coolant sensor. Please keep us up to date on your progress and thank you for using 2CarPros!
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Dec 10, 2019 at 5:05 AM
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