supermanjcttu

I could really use some advice. I am new to the forums and have just shipped my wife's 07 GT from Austin Texas, about 60 F when we left, to Anchorage Alaska, about -20 F when we picked up the car. It was shipped with only a quarter tank of gas. While in Texas before I shipped the car I put on all the parts I bought for it. I added Dynatech headers and X pipe, with Stinger 66 axle back system, an S&B CAI, BBK twin throttle body spacer, Motoblue Coil on Plug assemblies and a Predator tuner which I tuned for 93 octane fuel. When we picked up the car, we went to the gas station and filled up with 87 octane. Within a week of her driving it and leaving it outside at night, it threw a code of cylinder #8 misfire. I changed the plug and the problem has continued in addition to a shaking or stuttering at any speed, as well as at idle and especially during acceleration. Did I get some bad gas, or it is the change in whether, maybe water in the gas? Any help would be appreciated.

howarmat

you cant use 87 octane with a 93 tune......

Hufenstang

sounds like you didnt use 93 octane gas for the 93 octane tune

hammeron

hello superman and welcome...

the easiest fix for you, would be to upload
an 87tune....

do this and then let us know how the car
runs...

baker 46

Change the fuel filter and load an 87 octane tune. That should fix the problem.

Diabolical!

You can't run 87 oct with a 93 tune. Also, I wouldn't trust CoPs made by RPM outlet's sister company (motoblue).

supermanjcttu

Thanks for the info guys. I have uploaded the stock tune again and filled up the car with 90 octane, the highest in Alaska, and added some ISO-HEET. I have run another half a tank of gas through it and it hasn't gotten any better yet. Does anyone else have a car in as cold of weather as -20 F or so? It is possible that the 87 octane fouled up the spark plugs, I have extras on hand and can change them out also if that is a good idea.

hammeron

is the tune you have loaded now, written
for ALL of the mods that you have now?

supermanjcttu

Hammeron, the tune I have loaded now is just the stock tune, I put it back to stock because of the lack of higher octane fuel. Will resetting the computer by disconnecting the battery help any?

hammeron

so you have the stock ford 87 tune in now....

do you still have the cai, throttle body spacer, headers etc.. on
the car?