studebaker57
 

coincidence??
Filled up with gas and a few hours later was hard starting. Put in some injector cleaner and drove it around for a half an hour, all seemed fine except I noticed that it did not always upshift normally. I could manually get it to upshift.Let it sit a few days and it started right up, went for a ride and ran fine, still not always upshifting as it should. It is a 2008 Roadster. Hard starting and not shifting a coincidence??

Re: studebaker57
 

So the engine is apparently being fed such bad gas that it can't start easily and may be producing less power or misfiring?

That would imply you are pressing farther on the pedal, opening the throttle more to get the car to run - the computer will see this (I guess) as if you are pulling more of a load, or you are at high altitude. How else can it compensate for this other than delay the shifting?

SOunds to me like you already know what the issue is: Bad Gas.

Injector cleaner won't fix that - either burn the gas out of it by driving or drain the tank - then buy 'good' gas and see where it goes from there.
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Now, I have not had personal experience with "bad gas" in at least 30 years, but I DO hear about it from time to time.

Re: studebaker57
 

Thanks pizzaguy,
that is on my agenda, drain gas and replace fuel filter. Your thoughts do make some sense, we live at 7,700 feet so it might just be trying harder to shift.