Engine hesitation quick fix
09-04-2015, 12:28 PM
#17
Another easy answer!
09-09-2015, 09:32 AM
#19
Burning Brakes
I see posts from time to time reporting engine hesitation at part throttle/low rpm. Well, I do get that from time to time, but now I know why. Bad gas. I had an obvious case of slight engine hesitation until I got a full up.
So if you experience engine hesitation, I suggest you try another gas station (yes, some gas station cheat and dilute higher octane fuel with regular), or try changing a brand altogether.
I think that hesitation is most obvious is due to the fact that the ecu tries to lean out the mixture at low rpm/part throttle to get more efficient burn/save fuel, and when you mix in some subpar gasoline you get detonation.
So if you experience engine hesitation, I suggest you try another gas station (yes, some gas station cheat and dilute higher octane fuel with regular), or try changing a brand altogether.
I think that hesitation is most obvious is due to the fact that the ecu tries to lean out the mixture at low rpm/part throttle to get more efficient burn/save fuel, and when you mix in some subpar gasoline you get detonation.
I guess all the gas stations I visit in the Northern VA area have bad gas. Dang.
09-09-2015, 05:24 PM
#20
Rennlist Member
I've been somewhat hesitant in posting this as it seems counter-intuitive but here goes.....
In the UK we tend to be faced with 95RON as standard and the premium brands like 'Nitro' and 'Momentum' at 99RON. I have a history of using these higher octane fuels in my higher powered cars as I'm a bit of a marketing teams dream when it comes to up-selling....however... I do occasionally let sense prevail and use 'standard' grades in my cars...
Now it may be placebo effect but I honestly feel that running the LOWER Octane 95 RON fuel yields far less stumbling / hesitation in my C4S (still there but to a much lesser degree)... I wasn't looking or testing for this when I noticed it (over a year ago).... And there are far too many variables to rule out other factors (temperatures, driving style etc)... But it seems to be a consistent improvement.
I don't have a bad case of the stumble but I do notice it and it does have better and worse days.... and the difference with lower octane fuel feels substantial enough to tend to using it more and more (although not 100%).
I know these octane ratings are typically higher than US but there may be some logic emanating from this which might help someone more intelligent (and more troubled) than me piece together an improvement to their issue.... (I am sure Porsche already know exactly what the real issue is and how to fix it but have other factors they need to take into consideration preventing them from a full fix ... Cost, emissions, performance, reliability etc)
If I am completely disillusioned then please let me wallow in my ignorance but hopefully this info might be relevant and land in the hands of someone who can do something useful with it.... OaO
In the UK we tend to be faced with 95RON as standard and the premium brands like 'Nitro' and 'Momentum' at 99RON. I have a history of using these higher octane fuels in my higher powered cars as I'm a bit of a marketing teams dream when it comes to up-selling....however... I do occasionally let sense prevail and use 'standard' grades in my cars...
Now it may be placebo effect but I honestly feel that running the LOWER Octane 95 RON fuel yields far less stumbling / hesitation in my C4S (still there but to a much lesser degree)... I wasn't looking or testing for this when I noticed it (over a year ago).... And there are far too many variables to rule out other factors (temperatures, driving style etc)... But it seems to be a consistent improvement.
I don't have a bad case of the stumble but I do notice it and it does have better and worse days.... and the difference with lower octane fuel feels substantial enough to tend to using it more and more (although not 100%).
I know these octane ratings are typically higher than US but there may be some logic emanating from this which might help someone more intelligent (and more troubled) than me piece together an improvement to their issue.... (I am sure Porsche already know exactly what the real issue is and how to fix it but have other factors they need to take into consideration preventing them from a full fix ... Cost, emissions, performance, reliability etc)
If I am completely disillusioned then please let me wallow in my ignorance but hopefully this info might be relevant and land in the hands of someone who can do something useful with it.... OaO
