[Cougar5.0]

I forgot you have that custom A/A intercooler - maybe that's leaking or something.

My changes aren't something that can not work - they have to work as they align with how Ford designed the software to work.

[EDS50]

I forgot you have that custom A/A intercooler - maybe that's leaking or something.

My changes aren't something that can not work - they have to work as they align with how Ford designed the software to work.

Cougar5.0's specs worked perfectly for me. I have no idle issues what so ever now.

[roh92cp]

I forgot you have that custom A/A intercooler - maybe that's leaking or something.

My changes aren't something that can not work - they have to work as they align with how Ford designed the software to work.

I don't think is an air leak. I changed my setup to blow through and the MAF is right before the cold side pipe welded to the KB discharge. The only other leak it could be would be lower intake gasket and I don't think its that as I took care in sealing that well and pressure tested everything. Although I won't rule out air leak completly and will keep looking. I'm gonna try another pressure test.

[86GT]

Not sure about that. You have a breather on the valve cover. This allows metered air to escape to atomosphere. This is a big air leak. This is the reason ford routes this back to the intake and not out to atomsphere.

[Cougar5.0]

You have a breather on the valve cover. This allows metered air to escape to atomosphere. This is a big air leak. This is the reason ford routes this back to the intake and not out to atomsphere.

Uh-oh. I did this once and it really messed up everything idle-wise. I could barely get the car to go closed loop.

If you have a breather and you still have the PCV valve, that may be the issue.

[roh92cp]

I'm not sure it would matter in my case because I'm not drawing air in from the PVC valve or throttle body to valve cover. The PVC and both valve covers are vented. Nothing is drawing air from the intake or engine. I've run it this way before the A2A and never had issues.

[86GT]

The drawing air is not the problem it is the release of air that has already been metered by the MAF. The EEC is expecting to burn that air not release it.

[roh92cp]

The drawing air is not the problem it is the release of air that has already been metered by the MAF. The EEC is expecting to burn that air not release it.

So then the only metered air I can think of that could be released at the point after the MAF would be blow by.

[86GT]

The drawing air is not the problem it is the release of air that has already been metered by the MAF. The EEC is expecting to burn that air not release it.

So then the only metered air I can think of that could be released at the point after the MAF would be blow by.

Yes that is true but that blow by is usually re routed back to the intake after the MAF. It has to be a closed system.

[roh92cp]

The drawing air is not the problem it is the release of air that has already been metered by the MAF. The EEC is expecting to burn that air not release it.

So then the only metered air I can think of that could be released at the point after the MAF would be blow by.

Yes that is true but that blow by is usually re routed back to the intake after the MAF. It has to be a closed system.

Yes I do see your point, but I have been able tune my car before and never had big idle issues. I will go back to closed system and try to tune it that way.

[roh92cp]

I'm not sure the PCV system will work now with the blow through MAF. The PCV draws air from the Flowzilla which is allways in vac, and the throttle body draws air from the valve cover right. Under excess crank pressure like blow by both the PCV and the valve cover can release back into the intake track correct. Well that all works fine with a draw through MAF KB system, but I have a blow through KB MAF system. Now any air from PCV system that is routed to the VAC side of the blower like the Flowzilla or throttle body will be metered twice if it escapes via blow by. The only other alternative is to route the PCV to the discharge side of the KB which runs in vac and boost. The problem with routing the PCV this way is under boost the crank case pressure from blow by can not escape. I'm not sure how to precede with the PCV now that I've made this a blow through system. Any ideas guys.

[EDS50]

I feel your dilema, I have a similar set up and use a victor efi intake and it has no provision for pcv. Here is what I did and it works well. I ran a 6an line from my passenger side valve cover to an oil seperator I purchased at homedepot. I ran the line out of the oil seperator to the air inlet (air filter housing) for my supercharger. I never ran anything but a closed oil fill cap on the valve cover. I used to run a complete air pump evacuation system but had nothing but problems with the pump crashing after about 500 miles so I decided to go this route and it works perfect. I run a procharger race blow off valve in a blow thru configuration as well. If you run the pcv to the discharge side like you mentioned it would pressurize the crankcase under boost and would create all kinds of problems. Try it out it should work as it did for me. I can post pics and give you a step by step on how I did it and what you will need if it helps..

[roh92cp]

I feel your dilema, I have a similar set up and use a victor efi intake and it has no provision for pcv. Here is what I did and it works well. I ran a 6an line from my passenger side valve cover to an oil seperator I purchased at homedepot. I ran the line out of the oil seperator to the air inlet (air filter housing) for my supercharger. I never ran anything but a closed oil fill cap on the valve cover. I used to run a complete air pump evacuation system but had nothing but problems with the pump crashing after about 500 miles so I decided to go this route and it works perfect. I run a procharger race blow off valve in a blow thru configuration as well. If you run the pcv to the discharge side like you mentioned it would pressurize the crankcase under boost and would create all kinds of problems. Try it out it should work as it did for me. I can post pics and give you a step by step on how I did it and what you will need if it helps..

Still seems like if I did it your way the air would be metered twice. Also you didn;t mention what you did with the PCV line.

[EDS50]

error

[EDS50]

I feel your dilema, I have a similar set up and use a victor efi intake and it has no provision for pcv

How would it be metered twice? You are going to delete/plug your pcv valve and replace the breather element you have currently with a stock type oil fill cap. You run the line from your passenger side valve cover to the oil seperator and from the oil seperator to the air intake track/air filter inlet. The air intake will provide the required vaccum to pull/releive the crankcase pressure since the supercharger is sucking/drawing on it at all times and the oil seperator will keep/trap any oil from getting to the air filter and past it. Any and all air going thru your meter will only be metered once.[/quote]
Remember we are talking about a blow thru application., Not the conventional draw thru.

There are other ways to configure the routing but keeping it basic and functional is what I always strive for.

[86GT]

Because of the location of the MAF you are correct. The PCV needs to be route downstream of the MAF, otherwise it would be metered twice. Same is true for the valve cover vent. Here in californis I would never pass smog with them vented.

Either move the MAF back to draw through or find a way to get the vents downstream of the MAF

Oh one more thing replace the PCV with a 87-88 Turbo Coupe PCV. The internals are made of rubber and can hold positive pressure. The factory PCVs for the mustanf are all plastic and can not hold positive pressure. The PCV is supposed to work like a check valve. Having a blower connected makes the PCV leak. I hope that makes sense.

[Cougar5.0]

Maybe you could increase ARCHLK - Air - Air Charge Leakage.

[roh92cp]

Maybe you could increase ARCHLK - Air - Air Charge Leakage.

Hmmmm ARCHLK....interesting, So your saying keep my system the way it is and adjust for air leakage.

[Cougar5.0]

Maybe you could increase ARCHLK - Air - Air Charge Leakage.

Hmmmm ARCHLK....interesting, So your saying keep my system the way it is and adjust for air leakage.

Just a thought - it is an adder in the aircharge equation. On the other hand, it may do the opposite of what you want - lol.

In background, calculate the aircharge offset for leakage, ARCHLI (lbm/intake). The calibration constant, ARCHLK (lbm/min), includes all leakage terms not measured by the air flow meter (such as PCV, CANP, EVR
solenoid, etc.) Typical calibration value is 0.15 lbm/min for 5.0L.

ARCHLI (lbm/intake) = ARCHLK (lbm/min) / N * ENGCYL

ARCHI = RAWAIRCHG * ARCHCOR + ARCHLI

[roh92cp]

Maybe you could increase ARCHLK - Air - Air Charge Leakage.

Hmmmm ARCHLK....interesting, So your saying keep my system the way it is and adjust for air leakage.

Just a thought - it is an adder in the aircharge equation. On the other hand, it may do the opposite of what you want - lol.

In background, calculate the aircharge offset for leakage, ARCHLI (lbm/intake). The calibration constant, ARCHLK (lbm/min), includes all leakage terms not measured by the air flow meter (such as PCV, CANP, EVR
solenoid, etc.) Typical calibration value is 0.15 lbm/min for 5.0L.

ARCHLI (lbm/intake) = ARCHLK (lbm/min) / N * ENGCYL

ARCHI = RAWAIRCHG * ARCHCOR + ARCHLI

Cougar not sure I understand the explanation for calculating the aircharge leakage, its a little complicated for me. I did check and my ARCHLK was all 0 so I set it to 0.17 to start just a little more than the calibration you gave above. I'll see if that helps.

[roh92cp]

My stalling issue still persists now mostly when coasting to a stop, does not matter if its in nuetral or clutch is pushed in. It happens when it has not reached full warm conditions. Although it does dip down low sometimes even when fully warmed but does not stall. I don't think its an air leak issue at this point. I have allways run my car this way with no issues. This only started after the A2A upgrade which makes me think its an ACT temp issue. I've come to the conclusion its a fueling issue problem becasue it allways improves when the car is fully warmed. Today I looked at the to OL fuel tables FN1307 base fuel and FN1306 startup fuel and both I noticed are ACT and ECT ratio based on scalar FRCSFT. I allways though they were both strictly ECT based well I think this is part of my problem because my ACT temps are mostly below 100 deg all the time with the A2A. So that means the 2 fueling tables mentioned above are not setup with the right ration or lets say I never achieve the temps it was designed for with stock ACT temps of 200 deg. I was hoping someone may be able to help me adjust these tables. The formula in the comments says FRCBFT * ACT+(1-FRCBFT) * ECT. Could someone help me figure out how to adjust this scalar FRCBFT, its now set at 0.

OK after looking closer at FN1307 notes i found the bottom sentece that wa hidden which says if scalar FRCBFT is set to 0 than both FN1307 and FN1306 will be ECT based. I also found this out with some research. I still can't help but think there must be some other ACT based scalar or perimter that is causing this stalling problem. With ACT temps of under 100 degrees all the time how does that affect ACTFMM ACT default temp which is now set at 150. should I leave it there or change it. Not sure how that works.

[EDS50]

Just curious, did you try to use cougar5.0's idle settings exactly as he posted them? I am beginning to think we are "overthinking" the problem. You say the problem didnt start until you installed the a2a?

[roh92cp]

Just curious, did you try to use cougar5.0's idle settings exactly as he posted them? I am beginning to think we are "overthinking" the problem. You say the problem didnt start until you installed the a2a?

Your not wrong, I have been overthinking this issue. It would be nice to find something simple like a small vac leak, cap it off and all returns to normal. For the mean time I'm looking at everything and learning alot in the process. I did try Cougar's idle setting and still had the same issue with stalling. I'll try again just to make sure I didn't Fudge something up the first time.

[EDS50]

I run an a2a also. At one time I dint run an egr, iac or o2's and the car idled flawlessly at 800 rpm. When I converted the car back into a street car one of my projects was re-installing the hvac box along with the heat and a/c. After I did I had a problem with the car stalling like yours with the a/c on coming to a stop. The fix was re-installing the iac and adding a iac plate from ford racing. This instantly cured my problem. In your case the addition of the a2a and the tubing could be creating turbulence or a different airpath than what the maf meter and/or iac is used to seeing or sampling. With those additions your meter could be either sampling too much or not enough air under that certain decel condition or the iac's current adjustment is being overcome and unable to compensate for what its seeing. I would try to strive for a 800-850 rpm idle with your set up. I would reset the base idle first. Then try cougar5.0's settings exactly. If you are still experiencing stalling issues simply try to open the throttle body set screw a 1/4 turn clockwise at a time and test drive until your idle stabiltiy levels out. It may not be the answer but I used this technique on my n/a car and it fixed all of my idle problems and idles all around perfectly at 780-800 rpm. My blown car for some reason with the o2's deleted and such idles perfect at 800 rpm with the a/c on. I just chalk that up to luck...lol. Anyway try it out and see what happens.

[roh92cp]

Could be MAF turbulance, but Before going blow through MAF I had a draw through setup on here and it did the same thing. Riight now it idles high at 850 plus, If I adjust the idle screw up any higher the ISC DC goes to 18 and is out of the picture so I leave it there. Clint seems to think its my IAC trasfer that needs to be dialed in at this point. I'll work with him on that and see what happens.

[86GT]

At an idle the ISC needs to be around 32. If it is not then the ISC neutral function and or the TB air flow is out of wack. If it is at 17.5 or 18 then this is why you are stalling and the decel is stalling. What is happening is the ISC is cliped at the bottom and has no control over the idle. The ISC is supposed to ask as a dashpot and bring the idle down slowly. If it is going to 17 then it is not bringing it down slowly but as fast as it can.

[EDS50]

I didnt realize you had the same problem with the draw thru. I run a blow thru also. I would still reset your base idle to start with. Your problem definitly lies in your idle/isc set up. Get that right and your problems should go away.

[Cougar5.0]

Though my settings should work OK for a similar set-up, I was also hoping to just show the typical functions you'd expect to adjust when dialling in your idle so you might get some ideas. I'm surprised you haven't been able to fix the stalling. Between DASMIN and FN825A you'd think you could get the idle to stay up when coasting/declutch, using FN825A to hold the idle higher until the engine is full warm.

I'm not sure why you even talk about the throttle stop screw, for any particular idle RPM setpoint, there is only one spot you can put that screw and have the correct ISC duty cycle (assuming all other air leakage is the same)

[EDS50]

Though my settings should work OK for a similar set-up, I was also hoping to just show the typical functions you'd expect to adjust when dialling in your idle so you might get some ideas. I'm surprised you haven't been able to fix the stalling. Between DASMIN and FN825A you'd think you could get the idle to stay up when coasting/declutch, using FN825A to hold the idle higher until the engine is full warm.

I'm not sure why you even talk about the throttle stop screw, for any particular idle RPM setpoint, there is only one spot you can put that screw and have the correct ISC duty cycle (assuming all other air leakage is the same)

Thats not neccessarily true. Once I had my base idle set properly I was having a problem with the car stalling out when coming to a stop with the a/c on. I had to open the throttle set screw a little more (1/4 turn and probably because I was trying to target a lower idle point than what you have yours set to at the time) than what I had originally adjusted and fine tuned PSIBRN to get the car to not stall out anymore. That along with your settings worked perfect for me and my car is n/a so go figure. Adjusting PSIBRN and your settings is what worked for me. The reason I mentioned adjusting the throttle stop screw is because from what roh92cp is describing with his isc bottoming out at 18 his base idle is not set properly and the base idle on his car needs to be reset before he continues with his adjustments. Seems like right now he is p1ssing up a wet rope and needs to go back to the basics and start from the beginning and working from there. I have a good feeling that once he gets his base idle reset properly and uses your setting his car will be back to idling perfectly as yours and mine are.

[roh92cp]

At an idle the ISC needs to be around 32. If it is not then the ISC neutral function and or the TB air flow is out of wack. If it is at 17.5 or 18 then this is why you are stalling and the decel is stalling. What is happening is the ISC is cliped at the bottom and has no control over the idle. The ISC is supposed to ask as a dashpot and bring the idle down slowly. If it is going to 17 then it is not bringing it down slowly but as fast as it can.

If the ISC DC drops right down to fast than wouldn't the ISC dashpot decay rate be to first adjustment to bring it down slowly.