Awesome video. Saw a couple people's videos complaining about this being a downside to the fitech. Thanks for explaining it so well. I'm almost done installing the fitech on my '67 mustang. Your videos have been a big help!
Nash, around 2:52 you said "that you want to set your decel cut MAP below..." your max vacuum (which occurs during deceleration). I dont have a FiTech but based on what I know about fuel injection in general it sounds like you are disabled the DFCO function because the MAP value never goes below 17 you have set. An easy way to test this would be to set the "decel cut MAP" to a much lower number (5) if there is not change in the popping then you have disabled the DFCO. Since the DFCO is never engaged, the "decel return MAP" value shouldn't matter. So the real question is, why is the popping happening? The most likely cause is air and un-burnt fuel are mixing in the exhaust pipe and igniting. That ignition makes the pop sound. So the real problem is that you are running too rich before the DFCO engages which is putting un-burnt fuel into your exhaust. Another way to fix the problem would be to run a Catalytic converter because the CAT would burn the un-burnt fuel before it would have a chance to pop but running too rich all the time can burn up a CAT. If you want the DCFO to function you would want the "decel cut MAP" to be about 1 or 2 above the lowest MAP you see when decelerating. Then, set the "decel return MAP" to ~1 less that the lowest MAP value you see when idling in park. Even FiTech is to lazy to explain the detail and say "[Popping] is normal because fuel is being shut off under decel. If you should off decel the popping will go away. Just change Decel Cut MAP to 5." fitechefi.com/faq/rev-limit-decel-cut/ All new cars use DFCO and they never pop. All of this stuff is in the name of fuel economy and emission so if you don't care about those thing there is not reason to use DCFO or lean out you mix to put less fuel into. I could write more but i am going to stop.
I'm going to tell you how to set this since the video doesn't fully explain this and adds more info than you really need. This setting has nothing to do with looking at your vacuum readings like it says in the video. What you need to do is go into the options and choose "MAP" for your large gauges. Take your car for a drive and find a long hill you can drive down while the car is in gear. This can done at any RPM, but try coasting down the hill in gear at a higher rpm and look at your MAP reading while you are completely off the throttle, in gear, and then see what the MAP is reading. My car for instance, the MAP was reading around 32 off the throttle around 2500 RPM. All I had to do was go into the DFCO Setting and set that first number (Decel Cut MAP) to 34. What that is telling the computer, is that for any MAP reading under 34, cut the fuel. Off the throttle, my map is reading 32 and since i told the computer to cut the fuel for any readings below 34, no more excess fuel is being tossed into my exhaust which in turn, NO MORE POPPING. For the Decel Return MAP, mine is at 36. Once you are back on the throttle, that MAP reading is going to increase alot, so the fuel will turn back on. I don't know why fitech doesn't explain this. They just say "automatics are set for this number" and "manuals are lower and should be set to this" The most crazy thing fitech said is if you want to turn this off, just set this to like 5. If you set that number to 5, your telling the computer to just keep dumping fuel into your exhaust off the throttle because the MAP reading will never reach that number. You don't want to do this. This will only increase the popping in your exhaust, Trust me, I've done this before I knew how to fix this. and thats what it did. So this is all you need guys and your popping issues will be resolved.
Man I’d like to meet up with you one day. I have a1985 k10 I bought last November. My truck also, has an EFI and would like to learn more about it. Man this pick up rocks. I live in Middle Tennessee.
Know that you talk about what NOT to do as so dropping them would be bad , I already did mine before you did your’s PS you’re show Rocks (have a 69, 302, 44f 9in and I’m 60yrs)
I noticed when I'm in deceleration up to a stop light, my ARF goes to 10.8. When I excel its stumbles then ARF goes to 14's and runs fine. Is this where decel cut map and decel return map come in play. Thanks great video's
Did u get your controller fixed from dying or did I miss that video, also you had another efi set up to try out what become of it and did run it or send it back ?
Awesome video. Saw a couple people's videos complaining about this being a downside to the fitech. Thanks for explaining it so well. I'm almost done installing the fitech on my '67 mustang. Your videos have been a big help!
Awesome man! Glad I could help!
Nash, around 2:52 you said "that you want to set your decel cut MAP below..." your max vacuum (which occurs during deceleration). I dont have a FiTech but based on what I know about fuel injection in general it sounds like you are disabled the DFCO function because the MAP value never goes below 17 you have set. An easy way to test this would be to set the "decel cut MAP" to a much lower number (5) if there is not change in the popping then you have disabled the DFCO. Since the DFCO is never engaged, the "decel return MAP" value shouldn't matter.
So the real question is, why is the popping happening? The most likely cause is air and un-burnt fuel are mixing in the exhaust pipe and igniting. That ignition makes the pop sound. So the real problem is that you are running too rich before the DFCO engages which is putting un-burnt fuel into your exhaust. Another way to fix the problem would be to run a Catalytic converter because the CAT would burn the un-burnt fuel before it would have a chance to pop but running too rich all the time can burn up a CAT.
If you want the DCFO to function you would want the "decel cut MAP" to be about 1 or 2 above the lowest MAP you see when decelerating. Then, set the "decel return MAP" to ~1 less that the lowest MAP value you see when idling in park.
Even FiTech is to lazy to explain the detail and say "[Popping] is normal because fuel is being shut off under decel. If you should off decel the popping will go away. Just change Decel Cut MAP to 5." fitechefi.com/faq/rev-limit-decel-cut/
All new cars use DFCO and they never pop.
All of this stuff is in the name of fuel economy and emission so if you don't care about those thing there is not reason to use DCFO or lean out you mix to put less fuel into.
I could write more but i am going to stop.
Such a good explanation! Thank you! I’ve learned a little about dfco but this helps a ton.
I'm going to tell you how to set this since the video doesn't fully explain this and adds more info than you really need.
This setting has nothing to do with looking at your vacuum readings like it says in the video.
What you need to do is go into the options and choose "MAP" for your large gauges.
Take your car for a drive and find a long hill you can drive down while the car is in gear. This can done at any RPM, but try coasting down the hill in gear at a higher rpm and look at your MAP reading while you are completely off the throttle, in gear, and then see what the MAP is reading. My car for instance, the MAP was reading around 32 off the throttle around 2500 RPM. All I had to do was go into the DFCO Setting and set that first number (Decel Cut MAP) to 34. What that is telling the computer, is that for any MAP reading under 34, cut the fuel. Off the throttle, my map is reading 32 and since i told the computer to cut the fuel for any readings below 34, no more excess fuel is being tossed into my exhaust which in turn, NO MORE POPPING. For the Decel Return MAP, mine is at 36. Once you are back on the throttle, that MAP reading is going to increase alot, so the fuel will turn back on.
I don't know why fitech doesn't explain this. They just say "automatics are set for this number" and "manuals are lower and should be set to this" The most crazy thing fitech said is if you want to turn this off, just set this to like 5. If you set that number to 5, your telling the computer to just keep dumping fuel into your exhaust off the throttle because the MAP reading will never reach that number. You don't want to do this. This will only increase the popping in your exhaust, Trust me, I've done this before I knew how to fix this. and thats what it did.
So this is all you need guys and your popping issues will be resolved.
That’s a great explanation, thank you. I agree, it’s pretty crazy that fitech doesn’t explain this.
Too bad. We used to love the sound of the glasspack exaust popping on decel!
Man I’d like to meet up with you one day. I have a1985 k10 I bought last November. My truck also, has an EFI and would like to learn more about it. Man this pick up rocks. I live in Middle Tennessee.
I am glad you posted it. I will be working on this next. Mine pops and backfires. Well along with the many other noises we are all familiar with.
Haha! So true! Hope it helps
keep it up the videos are very helpful . only you and 2 others real seam to under stand the fitech i will be putting one on my 69 runner .
Awesome info.!
Nice. Suggestion for the next video...replacing the knob on your gear selector ;-)
😂 yeah there’s still a lot of work to be done on my Bronco
First! Love onboard diagnostics. Great vid
Thanks man!
Well done sir :)
Fixed that right up. Only thing is I don’t see option for vacuum gauge.
No option for a vacuum gauge with the FiTech system? Hmmm...
No, I have the 31004 one, maybe it doesn’t have that option although I don’t know why it wouldn’t.
The differences of the units don’t make sense to me either
Great system though and your videos have been very helpful, thank you.
@@NashvilleEarlyBronco Just finding these videos and mine doesn't have the vacuum gauge either.
Know that you talk about what NOT to do as so dropping them would be bad , I already did mine before you did your’s PS you’re show Rocks (have a 69, 302, 44f 9in and I’m 60yrs)
Thanks man!
I noticed when I'm in deceleration up to a stop light, my ARF goes to 10.8. When I excel its stumbles then ARF goes to 14's and runs fine. Is this where decel cut map and decel return map come in play. Thanks great video's
very helpful
Did u get your controller fixed from dying or did I miss that video, also you had another efi set up to try out what become of it and did run it or send it back ?
good info.
Look forward to learning about Broncos. I have a fitech but have not done much with it. If you find time check out my channel.
Mine actually spits flames from the exhaust but the AFR is set at about 15. Is there any other controls that might make it pop and backfire?
Have you watch my video on timing? The timing being off will make it backfire
What do you do if your backing plate for your door hinges fall down behind the door pillar ????
How do I retrieve them ???
You have a fish them out or cut the pillar and pull them out. Not fun. On my door alignment video I talk about how to keep them in place
Which one do you set at 5 to basically disable the fuel cut off?
Decel Cut MAP
From now on I”lol be Monttee from Missouri K
Deal