[obermd]

After checking the spark plug gaps - set them to 0.028"-0.030" and a couple of tanks of 91/93 octane let us know. The next step would be to replace the plugs with NGK BKR8EIX (iridium) or NGK BKR7E (vPower copper). Both improve low RPM performance. The copper plugs will only last 10,000 to 20,000 miles however.

 

[obermd]

Bones,

If you haven't gotten the ECU recall done, get it done. This recall appears to also assist in hot weather.

 

[obermd]

I have a 14 Eco 6 speed manual, engine runs well even in hot weather so long as I keep the engine running more than 1500 rpm, I live in Indiana so not very much hot weather here, I have only run 87 and it runs fine. Sounds like the older 1.4 doesn't run well on 87 in hot weather.

There was a programming change for the 2014s that make them run a lot better on low octane (87) gas and in hot weather.

 

[obermd]

Amazon.com. You can order them singly or in a four pack. The four pack was cheaper but the prices do change daily.

 

[obermd]

sluggish as in it's almost to the point of stalling out. Has the occasional sputter, and has substantially less power than when it was 60F weather here.

I wonder if you have a vacuum leak that isn't large enough to set the P0171 code. Sitting at idle the only time I've had this type of problem was shortly before my car set the P0171 lean code.

 

[obermd]

Just a thought - reseat your oil dipstick.

 

[obermd]

The ECU reflash is only for the automatics. The manuals have a different ECU programming.

 

[obermd]

Bones, do what jblackburn suggested. I have run both of those plugs in my 2012 ECO MT in the Denver high altitude heat and there's a big difference. The OEM plugs are designed for longevity, not for drivability.

 

[obermd]

If this thing had a bored out 350 under the hood, I wouldn't be so pissed about running 100 octane. but burnin high octane just to get dust thrown in my face by every for focus in town leaves a bad taste in my mouth

This is why GM's marketing division insisted that Chevy's engineers figure out how to make an engine designed for 91 octane (KRD code) safely run on 87 octane. However, I suspect your problem isn't related so much to octane as it is heat soak and spark plugs that don't dissipate heat very well. There's nothing you can do about the heat soak but you can go with a better spark plug.

 

[obermd]

Make sure they're gapped at 0.029" and put them in.

 

[obermd]

Bones, anytime you take the ignition rail off you need to verify the springs aren't stuck against the boots.