4.3 vortec running rough when cold

Tyler55 · Oct 17, 2017

I replaced that a few months ago

c1500deathtrap · Oct 17, 2017

So a neat trick, on obd1 you can run what GM called field diagnostic mode. The only info it provides is if the computer is in open or closed loop. Useful for trying to narrow down issues that are fuel mixture related. Just jumper the A/B termibals on your ALDL and drive. The check engine light will blink super fast for open loop or blink slower for closed loop. see if going in or out of closed loop coincides with your issue.

c1500deathtrap · Oct 17, 2017

And you seem to have dropped your wrench.

Tyler55 · Oct 17, 2017

Funny story about that wrench lets just say she likes her new home and doesnt want to come out haha

Tyler55 · Oct 17, 2017

Just changed the temp sensor letting it cool completely to see how it runs. Seems to run a bit better warm though

Tyler55 · Oct 17, 2017

Didnt fix the issue gonna try the jump on my aldl see if that has an answer

Tyler55 · Oct 18, 2017

So did the jump and it was related to it dying. At first it blinked fast for a min and ran fine. Then it blinked slow for a few seconds and then stopped altogether. When the light stopped blinking it died. What does this mean ?

Tyler55 · Oct 18, 2017

I also just allowed it to spit codes at me with the engine off. I got 4 short and 4 short the most. If im reading it right that means a 44. This says o2 sensor or circuit. Im gonna try that but did i read right?

c1500deathtrap · Oct 18, 2017

You sure did! The slow blink indicates going into closed loop which means its reading from the o2 sensor now. so if it dies on the o2 sensor something is up with that circuit or the sensor itself.

c1500deathtrap · Oct 18, 2017

o2 sensors are cheap enough for that truck i would just buy one. But, a word of caution avoid Bosch o2 sensors the magic pixies in the ecu don't like Bosch o2 sensors.

4.3 vortec running rough when cold

Tyler55

Newbie

c1500deathtrap

I try

c1500deathtrap

I try

Tyler55

Newbie

Tyler55

Newbie

Tyler55

Newbie

Tyler55

Newbie

Tyler55

Newbie

c1500deathtrap

I try

c1500deathtrap

I try

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