Question: Air diverter question

[djsroknrol]

I changed about 10 ft of vacuum lines last weekend and found a plastic line disconnected from the back of the front TB in the process. When I restarted the car, it was cold and sounded like it was missing a cylinder. It warmed up and ran alright after that...my MPG even came up a couple of miles

My question is, would the reconnection mean that the ECM needs to relearn the change in vacuum before it straightens itself out again or could it be that something else is wrong?

 

[Hib Halverson]

It only takes a short time for the long term fuel trim...it was called "block learn" way back then...to adjust.

It is possible you have some other cold start or early warm-up issue.

 

[djsroknrol]

Ok...so a 7 mile highway run to work tonight should have set it back, but it didn't. The 7 mile ride home was the same; it starts cold and straightens out after 5 minutes or so. I need to check the vacuum connections again and inspect the EGR and the EGR solenoid while I've got the air cleaner off.
I still don't understand the increase in average miles per gallon when its runs so lousy on cold start.