Rough starting idle

[Schurkey]

Runs bad cold/when first started, gets better as it warms up?

Does the running get better suddenly, and does that happen when the vehicle goes into closed loop? (i.e., runs ****** in open loop, computer changes to closed loop, and "poof" it runs fine?)

 

[92rcsb]

Runs bad cold/when first started, gets better as it warms up?

Does the running get better suddenly, and does that happen when the vehicle goes into closed loop? (i.e., runs ****** in open loop, computer changes to closed loop, and "poof" it runs fine?)

Exactly, if I manually idle it up around 1500rpm and hold it there for give or take 30 seconds it smoothes out and runs great. No issues while driving after initial warmup

 

[magimerlin]

Exactly, if I manually idle it up around 1500rpm and hold it there for give or take 30 seconds it smoothes out and runs great. No issues while driving after initial warmup

Yup.... same issue I'm having.. if left alone, not manually idling it up, it will lope like it's a drag car...lol..

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[Schurkey]

Exactly, if I manually idle it up around 1500rpm and hold it there for give or take 30 seconds it smoothes out and runs great. No issues while driving after initial warmup

Yup.... same issue I'm having.. if left alone, not manually idling it up, it will lope like it's a drag car...lol..

Let me re-phrase. HAVE YOU CONNECTED A SCAN TOOL, and confirmed that the change in how it runs, takes place just as the computer switches from open loop to closed loop?

 

[magimerlin]

Runs bad cold/when first started, gets better as it warms up?

Does the running get better suddenly, and does that happen when the vehicle goes into closed loop? (i.e., runs ****** in open loop, computer changes to closed loop, and "poof" it runs fine?)

Yes runs bad at first. If I manually idle it for 10 to 20 seconds to bout 1000-1500 itll clear up all of a sudden and acts normal. The numbers I posted above are both still in open loop... left numbers are while its acting up. Right numbers are after it is manually idled up for 10-20 seconds and is leveled out and still in open loop.. my my issue is all in open loop..

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[92rcsb]

Yup.... same issue I'm having.. if left alone, not manually idling it up, it will lope like it's a drag car...lol..

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Exact same, I was going to start replacing sensors and the iac, but it looks like you've already tried that. I considered just replacing the ecm but I'd rather not spend $200 if I dont have to

 

[Schurkey]

my my issue is all in open loop..

Ok. I was guessing it was an open-loop problem that didn't exist in closed-loop. I guessed wrong.

I'm not sure where to go with this.

 

[LILJOEPEELZ05]

MAP sensor. A vacuum line runs from back of tbi to (facing engine) left side. Mine kept idling higher and higher. I pulled vac line to the MAP sensor and idle dropped to around 750. Sounded like I had a huge cam in it. MAP controls the fuel and air mix.


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[magimerlin]

MAP sensor. A vacuum line runs from back of tbi to (facing engine) left side. Mine kept idling higher and higher. I pulled vac line to the MAP sensor and idle dropped to around 750. Sounded like I had a huge cam in it. MAP controls the fuel and air mix.


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I know the line in question... I'll double check it.. I checked all my vac lines but no harm in checking them again.

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[LILJOEPEELZ05]

I know the line in question... I'll double check it.. I checked all my vac lines but no harm in checking them again.

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I replaced the MAP sensor. That was my problem. Prrrr’s like a kitten now


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