U7142 03 Cobra running at 10.0 a/f and below.

daveshelbygt · Post by **daveshelbygt** » Tue Mar 03, 2015 4:34 am

I have had this Cobra for a little over a year and have pretty much had the same issue for the entire time. The car is not driven hard and never raced. It has a 2.8 pulley, Magnaflow catted X-pipe, mufflers and tips, CAI, Moroso intercooler tank, Evenflow head cooling mod. Currently the 91 pulley tune is on the car.
For the time I have had it, at WOT the car sputters/hesitates if going from around 2k on up. Most noticeably when the car is warmed up. I recently added an a/f gauge and the car gradually drops to 10.0 at WOT. I assume it is going even lower that 10.0, but that is the limit of the gauge. Additionally I get a strong smell of unburnt gas if the windows are down. I have changed the plugs, coil packs and 02 sensors and nothing has made any difference.
I wonder if there is a different canned tune I can try or safe adjustment to get the a/f to safely run and avoid the risk of washing down the cylinders with fuel and inadvertently going too lean.
Thanks,
Dave

Post by **sohfast94** » Wed Mar 04, 2015 12:10 pm

You need a custom tune honestly. What type of CAI do you have? Did the tool have a tune for that?

daveshelbygt · Post by **daveshelbygt** » Fri Mar 06, 2015 4:34 am

: 745_4529.jpg (1.97 MiB) Viewed 4097 times

Yeah that is on the to do list. I don't know what brand it is, maybe a K&N it is not a full intake. Could a defective MAF cause it to run extra rich?

Post by **sohfast94** » Mon Mar 09, 2015 9:22 am

Defective MAF could cause it to do all sorts of bad things although I would think it would screw up a lot more than just wot.

Which plugs do you have and what are they gapped to?

daveshelbygt · Post by **daveshelbygt** » Mon Mar 09, 2015 2:54 pm

So yesterday I discovered the problem. The spark was blowing out under a load. I stupidly had the NGK TR6 plugs gapped to 0.38.

After doing some reading I found out this was incorrect for a pulleyed motor. I gapped them down to 0.30 and the car is now a beast, with much better A/F numbers. It still dips into the 10.0s but there is no more hesitation and it pulls hard and even all the way to the redline.
http://youtu.be/8cl9P07brQU The car now breaks the tires loose at 60 mph. :drivingbad:

Thanks for the help!

Post by **mikel** » Mon Mar 09, 2015 3:23 pm

nice

U7142 03 Cobra running at 10.0 a/f and below.

U7142 03 Cobra running at 10.0 a/f and below.

Re: U7142 03 Cobra running at 10.0 a/f and below.

Re: U7142 03 Cobra running at 10.0 a/f and below.

Re: U7142 03 Cobra running at 10.0 a/f and below.

Re: U7142 03 Cobra running at 10.0 a/f and below.

Re: U7142 03 Cobra running at 10.0 a/f and below.