Fitech idleing issues

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schwinger

schwinger

1972 Dodge Dart Swinger
Joined
Jun 24, 2008
Messages
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Location
Fresno, California
Been having this idleing issue for about about a month after my install and just got about 400 miles on it but It's been driving me crazy, idle keeps on going up and down from 800 which is my initial idle to 1500 back and forth and sometimes goes below that but that's after it's warm. Doesn't do it on first startup, But after I drive it then it does. Figure i drove it more for it to learn but didn't fix the idleing issue. Followed the iac step recommendations and got mine at 6, still does it. Someone mentioned lowering the idle learn max which I tried and put it down to 3 and still no go. tried calling fitech tech line several times but there's always a long wait period and when I get through they just take my number and tell me they'd call back which they never do. So much for customer service. Other than the idleing issue it takes off like a bat out hell and has great performance than the 600 cent carter carb i had on but the idleing is just blah. Just trying to get this resolved.
My setup is the basic 400hp with FCC no return line vented to the back.
318 magnum .040 over, decked block, not sure how much, flat top pistons stock rebuilt heads, speedmaster air gap magnum Intake
Reground roller cam 491/491 lift 108 lob separation
Dakota 5 spd
Ford 8" in the back with 3.25s
Got the engine setup on the display cam mild-wild set to 3
FFC set at 40 pwm
 
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Checked around the base of the fitech with carb spray as well as around the base of the intake awhile back but didn't see any change in idle speed but will check again. Pcv valve is fairly new but will check it tomorrow.
 
I was reading an article online from hotrod ( wish I could remeber the name) but they spoke about cams with tight lsa & efi and idle quality. They said you needed to set your base rpm to 1500 to overcome the extra O2 in the exhaust...
Don't know if this is your issue, just thought I throw it out there.
Good luck!
 
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If you do Facebook, there is a page called Fitech Owners Group. Lots of info and great bunch of guys that will help immensely. You have to belong to the group but it's worth it, helped me a great deal.
 
I had similar issues for quite some time and pretty well have them fixed.

These are merely suggestions--disclaimer

If you have a PCV Valve, and hooked it to only 1 side of the throttle body, and have a divided plenum intake, that may affect idle as the PCV valve may not be correct for your application and may be providing crankcase vapors on one side of intake only ( I use the Wagner Dual flow PCV, hooked into both 3/8 ports to provide flow to both sides of my dual plane)

Hook both fuel regulators to manifold vacuum, as per Fitechs instructions..( both FCC and Throttle body) , if not already done. This reduces my idle fuel pressure to about 48, instead of 58, and jumps up when vacuum drops.

In pro tuning, under AFR closed loop, i have the the loop speed set to over 40. This controls how fast the trim rate can react to changes

Play around with the idle trim rate and idle trim jump settings, ( 1 thing at a time, to see if it changes for the better. Some have reduced these rates very low, others not.. seee what helps

Many suggest setting the idle fuel learn rate to close to 2-3

In IDLE control, play with loop rate up and down, to see if that changes things for the better.

This thread has MUCH information that may help
FITECH EFI TUNING tips, info sharing, ideas, settings, etc... - Chevelle Tech

And possible try your engine on cam settings 2 to see if it helps.

Good luck. Mine is running fantastic.. the motor sings like never before.. :)
 
Ok I think I found my dillema! Did rechecked the pcv valve and is operating correctly but noticed I hooked up the brake booster vacuum line to the drivers side valve cover for some odd ball reason. Capped that off since I'm running manual brakes/no booster and... it's actually idleing great and stable. I can't believe I did that! Wondering what the heck I was thinking there. Gona Drive it some more and see if this problem comes back. Did spray around the fitech base as well as the intake and no change so I'm gona rule that out. I'll go ahead and join that Facebook group you mentioned wireweld. Yes it's a devided intake plenum, thought about putting a pneumonic spaced in there but if the problem comes back I'll fiddle around with that as well as Koop rate and such!
 
schwinger said:
Ok I think I found my dillema! Did rechecked the pcv valve and is operating correctly but noticed I hooked up the brake booster vacuum line to the drivers side valve cover for some odd ball reason. Capped that off since I'm running manual brakes/no booster and... it's actually idleing great and stable. I can't believe I did that! Wondering what the heck I was thinking there. Gona Drive it some more and see if this problem comes back. Did spray around the fitech base as well as the intake and no change so I'm gona rule that out. I'll go ahead and join that Facebook group you mentioned wireweld. Yes it's a devided intake plenum, thought about putting a pneumonic spaced in there but if the problem comes back I'll fiddle around with that as well as Koop rate and such!
Click to expand...
Excellent news!!! Good luck man!
 
Ok my problem came back but does it intermittently now around town but on a long drive the idle starts hanging to where I have to throttle the throttle quickly in order to get out of a some what cruise control which it happened before but went away. Thought the throttle was getting stuck since the tps showed 5% open when I let off so checked that at a stop and throttle is fine so idk what's going on there. Might have to relearn something or fiddle around the AFR closed loop rate but the loop rate in idle control I don't have that feature. Is there something I have to turn on and then it comes up or did I get an early unit that's SOL on that?
 
....following. I installed a Wagner dual flow PCV and installed it as winter set in and cold starts and idle have issues .......
 
I’d check to ensure front and rear butterflies are sync’d. I’d also raise the IAC a little. What’s IAC when engine is hot?
 
Ok it may be a different issue but I have a Holley Sniper with a similar issue. The TPS wasn't zeroing and the IAC didn't appear to be working properly. I had a look on the Holley sniper forum and found out that the TPS that comes with it is a cheap and nasty piece of poo. It is however a GM style unit. So off to the parts store I went and got a good quality TPS switch that looked exactly the same as the one off the Holley, a GM unit, and wammo.... the thing is back to normal with no TPS zeroing issues or IAC issues. Apparently its a common problem where the sensors if they get any moisture near them they crap themselves and cause all sorts of grief. Hope this info helps.
 
Ok sorry I’ve been away for awhile. Been busy working and holidays and such. I lived with the problem since April just on long drives it would come then I’d driving it around town and it would go away but just recently it came back with vengeance. Problem is not going away. even recalibrated the system by setting it back to default and re-entering my parameters still having the issue. Changed the tps also no effect. Starts doing it when I take off from idle when I first start it but blipping the throttle makes it going away sometimes. I made sure the butterfly’s were synced which they weren’t before. I don’t have a regulator, just a line that goes from the mechanical fuel pump to the FCC and to the fitech. I’m gona see if something is hanging up or replace the iac sensor also. Possibly that might be crapping out so I’ll keep you guys posted
 
The regulator is built into the TB when using a return, or the one in the top of the FCC is used when the fuel is dead headed to the TB. I would start by swapping the regulator from your throttle body to your FCC.
 
Oh ok. I have it dead headed to the TB but I’ll switch it and see if that works. Gona have to do it on Monday since I’m out of town but will get to it soon.
 
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