Hah makes sense!

 

I drove about 60 miles to one of my remote offices this morning....

drove between 75 - 90 MPH...

i coasted at those speeds and the AFR stayed between 13.8% and 14.3 the whole time regardless if i was in gear or not. thats how i imagine it should be.

 

Yeah I'd say so... Steeda is still crafting their response. I guess lets see how they explain it?

 

I'm sure they will work for you and get it right. They are a good brand and have never heard anything bad from them

 

Yes, we are trying to be as detailed as we can without creating a novel.

Should have something shortly.

Best Regards,

TJ

 

Just curious, how are you reading your AFR?

 

Information Center on Premium 13-14s. It's in the gauge cluster.

 

This is interesting. After reading your post I went out to the interstate this morning to check how my '14 GT would act at high speed. I knew it was shutting off the fuel when coasting in gear at lower speeds. Anyway, I ran tests at 50 mph and every 10 mph faster up to 100 mph. At every speed when I took my foot off the gas with the car in gear and the clutch engaged, the AFR gauge would go to around 12.5 for just about a second, then peg at 20. I could also feel the fuel being shut off when the needle pegged. As soon as I would push in the clutch or put in in neutral with the clutch out (engaged) the AFR gauge would immediately go back to 14 indicating fuel was again being supplied. I believe this is exactly the way it is supposed to work, but perhaps the v6's and v8's are set up differently. I know I had read somewhere on the 'net that was a fuel saving feature of the GT's, but I can't remember where. I will try and find it again.

I found some more information. This is called Deceleration Fuel Cutoff (DFCO)
And has been around in most cars since 1996.

 

Interesting indeed, Dave. Thank you for the insightful post!

 

this could be true. i don't recall ever seeing it jump to 20 while in gear and letting it coast. I do put a lot of highway miles daily, I'll give it a go tomorrow and will check and see how it goes!

and yup. through this beautiful informative 4" LCD display. has all kinds of useful/useless information

 

I tried this with my v6/steeda tune and it wouldn't stall.

 

cool. it does jump to 20% if you leave it in gear and let it coast for even a second. good indication that you actually are saving on gas if you leave it in gear and let it coast rather then to throw it in Neutral where you may get a little bit more roll, but burn gas at the same time.

in the end though - if you REALLY wanted to save on gas, don't speed and try to justify fuel economy by letting it coast

but... the important thing is that the car doesn't stall out no matter what. that's a flaw no doubt in the OP's setup.... somewhere.

 

I agree it appears to be flaw in the OP's setup. I would guess that somehow the tune has messed up the DFCO so the fuel flow is not being turned back on when the car is placed in neutral. I don't know how this could happen, but if the problem was not there before installing the CAI and tune then there is no doubt where the fault is. OP, don't let them tell you this is normal because it is not! If they cannot fix the problem demand your money back.

 

A simple way to verify that would be to restore the factory tune and drive it....

 

While doing some datalogging today, I was unable to recreate the issue...

AFR still jumped to 20% for a second while in neutral o_O

 

You don't need to justify it. Your fine going into neutral in a manual car. 90 mph or not. You'd have slowed down quite a bit before anything really had an effect. This idea is so dumb to think a car will stall out being placed in a nutral position or taking it out of gear because of turbulence and air getting jammed into the intake....it's not possible with how everything is set up unless your intake tube sticks out from the front of the grill and is with out a filter.

Now I had an instance back when I was completely stock. I was in cruise control and went to down shift from 6th to 4th while at 65 mph and the engine just shut off. Everything stopped working and while coasting I had to re crank the engine. It only happened one time and hasn't happened since. Very odd.

 

I think Steeda is hoping we'll stop talking about it. lol.
Any update there TJ?

 

Yes I agree. They were going to have something "shortly" 6 days ago! This whole incident just confirms why I don't trust tunes from any company except Ford Racing, and I'm not even sure about them!

 

I can confirm that the v6 changes the afr when coasting. It jumps up to 20:1. I logged it through the obdii port; not sure if that's different info than what's displayed in the guage cluster. Does anyone know if it's actually at 20:1, or if that's just where the boundary of the sensors is?

 

I think y'all mean 20:1, not 20%. Stoich is around 14:1. 20% (4:1) would be super super rich and not really save on gas.