02 Vulcan skippin at idle

[Willyum]

Can't find a thing wrong with it, no codes. Runs great down the street but backing out of the garage from cold start, it barely runs.
I see lots of questions about similar situations but no one reports in when they have fixed it. (or maybe they traded it off?)
Many thanks if you have some ideas.

[shorod]

Sounds like a vacuum leak. Did you recently perform some service that might have contributed to this? If so, check those areas for vacuum lines that might be cracked, broken, or disconnected.

The DPFE sensor is a pretty common issue that could cause your symptoms as well.

-Rod

[Willyum]

Thanks Rod.
It has been doing it to various degrees, mostly when cold backing out of the garage after a cold startup. Have always considered it a "quirk" of the vehicle.
I cleaned the throttle body and the MAF. Should have checked rather than changed the OEM spark wires, made no change.
Any way to check the DPFE ?

[shorod]

If you have a scan tool with datastream you can probably check the operation of the DPFE, but I'm not sure what a good one should look like versus a bad one.

-Rod

[Willyum]

Replaced the DPFE valve/sensor on a W.A.G. with no help. Looking it over for a vac leak is overwhelming. Wondering where to start.

[shorod]

One other thought, how old is the battery?

As for where to start looking for vacuum leaks, I'd suggest starting with the easy to see stuff such as the intake air tubing (including checking the accordion folds for cracks) and visible lines. Then if you don't find anything, check the PCV elbow (I'm not positive your car has one - may have been more of a Duratech issue) for cracks or signs of collapse.

-Rod

[Willyum]

Thanks again for trying to help with this.
Battery installed 13 mos ago.
Car is always garaged at home, which is most of the time. Under hood items all in excellent shape. PCV is a short little tube with valve at base into valve cover. That did split and I replaced it with OEM.
Have you heard of the plug boot arcing seen at another post? Dielectric grease necessary on those?

[shorod]

Dielectric grease shouldn't be necessary, although I suggest using it anyway. It's not so much to prevent boot arcing, the boot is a better insulator than the grease anyway. It's more to prevent the boot from sticking to the spark plug and to seal out moisture and dirt from getting under the boot.

-Rod

[Willyum]

It does seem to be much improved with the new DPFE sensor/valve. I had to do a water pump job on it at the same time which should have made no difference with it.