Fox Drivability issues

KRUISR

5 Year Member
Apr 16, 2015
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Is the dark colour on the plugs soot or oil?

When you set the idle, did you unplug BOTH the spout connector AND IAC plug? Before I set idle this way I would still get surging and stumbling issues.

What is your timing set at?

Is your car a factory 5 spd car or auto swap?

Is the MAF stock or aftermarket? If aftermarket, which one?

Here is a cold start video of mine from last summer. I have similar mods and have the dual wideband as well.


View: https://www.youtube.com/watch?v=qU6MAVZAcQU&t=10s
 
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Maciasmarci

Member
May 19, 2021
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Stockton
Is the dark colour on the plugs soot or oil?

When you set the idle, did you unplug BOTH the spout connector AND IAC plug? Before I set idle this way I would still get surging and stumbling issues.

What is your timing set at?

Is your car a factory 5 spd car or auto swap?

Is the MAF stock or aftermarket? If aftermarket, which one?

Here is a cold start video of mine from last summer. I have similar mods and have the dual wideband as well.


View: https://www.youtube.com/watch?v=qU6MAVZAcQU&t=10s

Is the dark colour on the plugs soot or oil?

When you set the idle, did you unplug BOTH the spout connector AND IAC plug? Before I set idle this way I would still get surging and stumbling issues.

What is your timing set at?

Is your car a factory 5 spd car or auto swap?

Is the MAF stock or aftermarket? If aftermarket, which one?

Here is a cold start video of mine from last summer. I have similar mods and have the dual wideband as well.


View: https://www.youtube.com/watch?v=qU6MAVZAcQU&t=10s

It’s not oil more like soot. No I didn’t unplug the spout connector only the iac but I make sure I have my timing set at 10 degrees Before I adjust the iac. Then reset the tps. Set at 10. No it’s a auto swap, maf.
 

KRUISR

5 Year Member
Apr 16, 2015
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No I didn’t unplug the spout connector only the iac
You definitely need to do both.

Follow the below steps. It is compiled by others here (just search Base Idle Reset). I found this condensed summary easier to follow and as mentioned was created by others much more knowledgeable than I on the topic. I just know it worked for me.


Before you start:
-Make sure your distributor will allow full movement to adjust timing. Things could move once you actually set everything correctly. My TFI hit the thermostat protrusion of the lower intake and would only go to 6 or 7 degrees. If I stabbed it the other way it was useless. So guess what. This meant I had compensated for the low timing and low idle with the throttle blade stop. This also meant that once I set timing properly, everything else was off a decent amount. I had to clearance the corner of the TFI module in order to get total adjustability. You can't know these things unless you go ahead and set the timing.
-Car out of gear, e brake on, timing light set up, multimeter ready for the TPS adjustment, all necessary tools ready.

Now do the process.
1. Warm the engine up to normal operating temperature.
2. Turn all accessories off. Lights, radio, hvac, etc.
3. Unplug the IAC electrical connector.
4. Remove the spout plug at the distributor connection.
5. Start the engine.
6. Idle the car to 600-650rpm using the throttle blade stop.
7. Turn the engine off but leave the key in the on position.
8. At this point you can set the TPS. (I'm not getting into the TPS setting debate. Put it on .9 anything and it's fine.)
9. Turn off the ignition and reconnect the IAC electrical connector and plug the spout plug back in.
10. Disconnect the negative battery terminal!!!! Let the car sit for at least 30 minutes.
11. Reconnect the battery.
12. You should still have all electrical accessories off. Start the car and let it run for 2 minutes. You should see the computer make adjustments. Time this with your phone or watch. Don't guess at it.
13. Turn the car off for 2 minutes.
14. Now turn the HVAC blower motor to high. Turn the A/C to Max. Turn the headlights on. Turn the radio on. 70's or 80's stations give the best results!
15. Start the car and let it run for two minutes. Don't guess at the time.
16. Turn the car off.
You should now have the base idle reset done and your car hopefully won't stall every time you stop. It should have better manners across the board.

This should clear up -- when to plug the spout connector back in, when to disconnect the battery, and how long to wait for the computer to make adjustments, and the process of starting the car once with all accessories off then again with all on.

Hope this complete list can make it in a spot just for base idle reset only. It's sole purpose is to help folks.


This process assumes you don't have vac leaks, bad plugs, wires or other things. Basically a sound engine system to begin with.

Also, to clarify my set up a bit in the video. It is an auto swap that is still using the A9P computer. It has 24lb injectors, Explorer intakes, 76mm C&L MAF, Crower 15512 cam with 1.7 RR (.512/.544), GT40 iron heads
 
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CAMTWO1070

Active Member
Dec 17, 2021
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NY
As I read the rundown of the engine build I see some inconsistencies....First are the injectors Second is the fuel pressure.

A B303 camshaft if Im not mistaken takes a 24 lb injector minimal and even if you boosted the fuel pressure to say 47lbs to increase duty cycle it still wont run right ..

You'll also need like a 76mm MAF and then have that MAF profile transferred in......

For your setup Id have no smaller than 30lb injectors w/340lph pump and have a Kirkey Adjusable Fuel Pressure regulator along with 76mm MAF.

After matching it all up youre gonna need someone to change the parameters in the ECU to match...especially the TPS, spark and fuel parameters.........

Good Luck
 

Monkeybutt2000

Mustang Master
Aug 11, 2019
940
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Lafayette,IN
As I read the rundown of the engine build I see some inconsistencies....First are the injectors Second is the fuel pressure.

A B303 camshaft if Im not mistaken takes a 24 lb injector minimal and even if you boosted the fuel pressure to say 47lbs to increase duty cycle it still wont run right ..

You'll also need like a 76mm MAF and then have that MAF profile transferred in......

For your setup Id have no smaller than 30lb injectors w/340lph pump and have a Kirkey Adjusable Fuel Pressure regulator along with 76mm MAF.

After matching it all up youre gonna need someone to change the parameters in the ECU to match...especially the TPS, spark and fuel parameters.........

Good Luck
Where did you get this info? This is a very mildly modded setup, 19#s will run that all day long.
 

CAMTWO1070

Active Member
Dec 17, 2021
67
26
28
52
NY
A MAF is a metering device for air and your BAP is like your altimeter showing your relation to sea level....Both are equally as important..

Heres what a stock MAF looks like in relation to the 90mm MAF I added.....The profile changes substantially....So does the amount of air it flows....

Screenshot 2022-04-09 165652.jpg
Screenshot 2022-04-09 165741.jpg


Then the Injector low and highslope needs to be adjusted along with spark etc....

Screenshot 2022-04-09 164135.jpg


Like I stated after making the necessary changes you'll need to hookup with someone who can make it all jive if you dont have the technology like a V3 chip and a Jaybird..

Good Luck
 

CAMTWO1070

Active Member
Dec 17, 2021
67
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NY
Where did you get this info? This is a very mildly modded setup, 19#s will run that all day long.
Its KNOWN FORD INFO....Look up B303 Camshaft recommendations and it says 24lb injectors....19's wont flow enough and besides if the flow exceeds the MAFs transfer settings it will go into limp mode everytime it does.....,

Im running a .477/.493 camshaft specs and I have to run 36lb injectors minimal in my 408 and it doesnt spin higher than 5500rpm's and is built for brutal torque....a b303 cam is bigger....LOL

Im not green to tuning..........
 

CAMTWO1070

Active Member
Dec 17, 2021
67
26
28
52
NY
Its KNOWN FORD INFO....Look up B303 Camshaft recommendations and it says 24lb injectors....19's wont flow enough and besides if the flow exceeds the MAFs transfer settings it will go into limp mode everytime it does.....,

Im running a .477/.493 camshaft specs and I have to run 36lb injectors minimal in my 408 and it doesnt spin higher than 5500rpm's and is built for brutal torque....a b303 cam is bigger....LOL

Im not green to tuning..........
Theres also info all over the info regarding crank hp to injector size like this chart they have at Summit.

Screenshot 2022-04-09 174209.jpg


These badboys flows enough fuel to ignite1900hp........

IMG_20210516_124558512_HDR.jpg
.
 

Mustang5L5

Put lubricant all over the balls
Mod Dude
Feb 18, 2001
39,196
15,097
224
Massachusetts
I’m going to respectfully disagree with needing a 340 lph pump and 30# injectors with a B303 and iron GT40 heads.

It’s a 306. It’s not moving anywhere near the amount of air your 408 is moving so the fuel requirements are going to be much less. Not exactly an apples to apples comparison.
 
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KRUISR

5 Year Member
Apr 16, 2015
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It’s a 306. It’s not moving anywhere near the amount of air your 408 is moving so the fuel requirements are going to be much less.
Agreed. At 5500 rpm your 408 is moving 649 cfm of air and needs an appropriate amount of fuel. The OPs 306 at the same 5500 rpm is only moving 487 cfm, much less fuel required. Your 408 pulls 33% more air and thus will need 33% more fuel.

CAMTWO1070 - As far as the chart you posted, I have seen versions with various duty cycles (your chart lists 0.80). My combo is a 302, with GT40s Explorer intakes, 70mm TB, 76mm C&L MAF, a Crower cam with .512/.544. I ran my 19s with this combo and on 1/4 mile marked on the street I would trap at 4950 rpm at 103 mph (leaving from idle), my car was a portly AOD car with me in it at 3750lbs. I have a dual wideband and an Anderson PMS connected (no tune, just data monitoring). When I shifted at 5500 the PMS showed duty cycle briefly at 95% and while at WOT the widebands showed steady low 13s, high 12s AFR.

So according to your chart, my combo should not be possible. Using various HP calculators online I get from 310-340 hp based on the above info.

My point - OP should be fine with 19s for a cruiser.
 
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Wayne Waldrep

Before I post a pic, do you have one of yours?
15 Year Member
Apr 14, 2003
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You definitely need to do both.

Follow the below steps. It is compiled by others here (just search Base Idle Reset). I found this condensed summary easier to follow and as mentioned was created by others much more knowledgeable than I on the topic. I just know it worked for me.


Before you start:
-Make sure your distributor will allow full movement to adjust timing. Things could move once you actually set everything correctly. My TFI hit the thermostat protrusion of the lower intake and would only go to 6 or 7 degrees. If I stabbed it the other way it was useless. So guess what. This meant I had compensated for the low timing and low idle with the throttle blade stop. This also meant that once I set timing properly, everything else was off a decent amount. I had to clearance the corner of the TFI module in order to get total adjustability. You can't know these things unless you go ahead and set the timing.
-Car out of gear, e brake on, timing light set up, multimeter ready for the TPS adjustment, all necessary tools ready.

Now do the process.
1. Warm the engine up to normal operating temperature.
2. Turn all accessories off. Lights, radio, hvac, etc.
3. Unplug the IAC electrical connector.
4. Remove the spout plug at the distributor connection.
5. Start the engine.
6. Idle the car to 600-650rpm using the throttle blade stop.
7. Turn the engine off but leave the key in the on position.
8. At this point you can set the TPS. (I'm not getting into the TPS setting debate. Put it on .9 anything and it's fine.)
9. Turn off the ignition and reconnect the IAC electrical connector and plug the spout plug back in.
10. Disconnect the negative battery terminal!!!! Let the car sit for at least 30 minutes.
11. Reconnect the battery.
12. You should still have all electrical accessories off. Start the car and let it run for 2 minutes. You should see the computer make adjustments. Time this with your phone or watch. Don't guess at it.
13. Turn the car off for 2 minutes.
14. Now turn the HVAC blower motor to high. Turn the A/C to Max. Turn the headlights on. Turn the radio on. 70's or 80's stations give the best results!
15. Start the car and let it run for two minutes. Don't guess at the time.
16. Turn the car off.
You should now have the base idle reset done and your car hopefully won't stall every time you stop. It should have better manners across the board.

This should clear up -- when to plug the spout connector back in, when to disconnect the battery, and how long to wait for the computer to make adjustments, and the process of starting the car once with all accessories off then again with all on.

Hope this complete list can make it in a spot just for base idle reset only. It's sole purpose is to help folks.


This process assumes you don't have vac leaks, bad plugs, wires or other things. Basically a sound engine system to begin with.

Also, to clarify my set up a bit in the video. It is an auto swap that is still using the A9P computer. It has 24lb injectors, Explorer intakes, 76mm C&L MAF, Crower 15512 cam with 1.7 RR (.512/.544), GT40 iron heads
Yeah i worked hard on that write up. You could have just linked it like we normally do.......:D