Reducing "Startup Flare" With An IAC "Restrictor"!!

[Marauderjack]

I found this trick on another forum and decided to try it on my Marauder!!

It is a restrictor plate put in between the IAC and the intake manifold reducing the "Lean" airflow condition in the OEM setup!!

I used some .025" aluminum sheet and made the plate with a 9/32 hole to start with as outlined in the Mustang discussion.....See attached photo.

In my case it works fine and even when cold the initial startup goes to about 1600 RPM's and falls back to 1100 RPM's within a second....Idles there fine and after warmup the startup "Flare" is only about 1200 RPM's for half a second!! :beer:

Also, on deceleration it actually gives a bit more engine braking with more exhaust "Burble"....VERY NICE!!!:D

If you decide to do this be sure and start with a 9/32" hole and open it up a bit if you have idle issues?? It also pays to disconnect the negative battery connection to allow the EEC to "Re-learn" the new IAC capabilities!!:rolleyes:

Marauderjack:bandit:

[LVMarauder]

... Dont restrictor plates reduce power , especially in the higher Rpms of our DOHC motors? Im confused about this thing where does it go and how does it limit the rev on startup

[Zack]

I found this trick on another forum and decided to try it on my Marauder!!

It is a restrictor plate put in between the IAC and the intake manifold reducing the "Lean" airflow condition in the OEM setup!!

I used some .025" aluminum sheet and made the plate with a 9/32 hole to start with as outlined in the Mustang discussion.....See attached photo.

In my case it works fine and even when cold the initial startup goes to about 1600 RPM's and falls back to 1100 RPM's within a second....Idles there fine and after warmup the startup "Flare" is only about 1200 RPM's for half a second!! :beer:

Also, on deceleration it actually gives a bit more engine braking with more exhaust "Burble"....VERY NICE!!!:D

If you decide to do this be sure and start with a 9/32" hole and open it up a bit if you have idle issues?? It also pays to disconnect the negative battery connection to allow the EEC to "Re-learn" the new IAC capabilities!!:rolleyes:

Marauderjack:bandit:

Great, but you can adjust what you did in the software with numbers, not power tools.

[MitchB]

Great, but you can adjust what you did in the software with numbers, not power tools.

Yes, but a little tricky. The MM's intake has a lot of volume and this makes controlling start-up engine speed a little more difficult.

Mitch

[Marauderjack]

LV....

The IAC ONLY works when the throttle butterflies are closed so.....No diminished power!!!:beer:

The rest of you guys.....I'll report back later after a few days with this "MOD"??!!:cool:

The Mustang guys have done it for over a year and like it.....as I do so far!!:beer:

I can take it out in 3 minutes.....but it has not stalled since it has been in....."Blower Stall" that Zack says is so common.....So far IT WORKS??

Marauderjack:D :D

[Marauderjack]

I started it this AM and tach jumped to about 1700 RPM's and fell back to 1100 RPM's in less than a second.....No drivability issues and it has not stalled since I did this!!:beer:

If I ran it before with only the vent and no A/C it would stall at idle if I tapped the throttle....Now it works fine with no stalling or hesitation!!:D

Marauderjack:rasta:

[Dennis Reinhart]

I found this trick on another forum and decided to try it on my Marauder!!

It is a restrictor plate put in between the IAC and the intake manifold reducing the "Lean" airflow condition in the OEM setup!!

I used some .025" aluminum sheet and made the plate with a 9/32 hole to start with as outlined in the Mustang discussion.....See attached photo.

In my case it works fine and even when cold the initial startup goes to about 1600 RPM's and falls back to 1100 RPM's within a second....Idles there fine and after warmup the startup "Flare" is only about 1200 RPM's for half a second!! :beer:

Also, on deceleration it actually gives a bit more engine braking with more exhaust "Burble"....VERY NICE!!!:D

If you decide to do this be sure and start with a 9/32" hole and open it up a bit if you have idle issues?? It also pays to disconnect the negative battery connection to allow the EEC to "Re-learn" the new IAC capabilities!!:rolleyes:

Marauderjack:bandit:


Nice post, but all this can be done with out the hardware using tunning

[TooManyFords]

Nice post, but all this can be done with out the hardware using tunning

Yes, if you're giving away tunes or xcal-2's that is...

The restrictor plate doesn't require owning an xcal-2 or paying the $100+ for tunes just to change the IAC. His solution is what, a couple dollars compared to ??

[Dennis Reinhart]

Yes, if you're giving away tunes or xcal-2's that is...

The restrictor plate doesn't require owning an xcal-2 or paying the $100+ for tunes just to change the IAC. His solution is what, a couple dollars compared to ??


Well I have never charged for a update, I have no idea what others do, some dealers do some do not. I believe he has Diablo tunning so maybe they do.

[Zack]

Yes, if you're giving away tunes or xcal-2's that is...

The restrictor plate doesn't require owning an xcal-2 or paying the $100+ for tunes just to change the IAC. His solution is what, a couple dollars compared to ??

Take a Mydol John :D

[Marauderjack]

What the hell is "tunning"??:confused: :confused:

If it is so easy why haven't some of you "tunner guys" spoken up before now!!??:confused:

I'm happy with my $1.50 restrictor so far!!:bows:

Marauderjack:bandit:

[MERCMAN]

Take a Mydol John :D


Are you taking spelling lessons from BigDog or Dennis? :rofl:

[RCSignals]

I started it this AM and tach jumped to about 1700 RPM's and fell back to 1100 RPM's in less than a second.....No drivability issues and it has not stalled since I did this!!:beer:

If I ran it before with only the vent and no A/C it would stall at idle if I tapped the throttle....Now it works fine with no stalling or hesitation!!:D

Marauderjack:rasta:

Ford has a TSB for a reflash if you are experiencing stalling/hesitation/rough idle at start up

[RR|Suki]

Ford has a TSB for a reflash if you are experiencing stalling/hesitation/rough idle at start up


wow read the posts before you reply...

[RCSignals]

wow read the posts before you reply...

wow, have a sense of humour?

[SergntMac]

Can anyone explain the goal here?

At 1.50, or, 150., why is this a mod to consider? Is it solving a problem?

I'm not having any start up problems, stock '03 engine, CRD1 SCT tune. Runs fine, what's up with the mod?

[Marauderjack]

Mac,

A number of owners have disliked the 2000 RPM "Flare" on cold startup.....including me but my main reason for trying it was stalling while idling without the A/C running!!:argue:

Zack said at one point that all S/C cars have stalling issues!!??:confused:

I had Scott Beer modify my Diablo Blower tune and it helped a bunch but still had stalling every once in awhile without the A/C running??:confused:

This restrictor seems to have fixed it completely and I just though I'd share it with the rest of you.....FWIW!!:shake:

A side effect of this "Mod" is a bit more engine braking and much better exhaust "Burble"....Which I like!!:D

The "Mustang Guys" especially like it with their straight drive cars since the exhaust sounds "Old School" without the RPM's "Hanging" between shifts!!:bows:

That's all........;)

Marauderjack:pimp:

[Loco1234]

thanks for the cool info....

[Marauderjack]

You're WELCOME.....Sir Loco1234!!:beer:

I'm getting tired of folks sniping and shooting holes in anything that may be remotely constructive!!:shake:

This place used to be like a huge SPONGE with regard to information and it seems it is becoming "Hydrophobic"!!:mad:

Buy yourself some aluminum flashing at Lowe's and make one from it...about $.50 and an hour of your time!!:cool: If it works for ya...make one of heavier gauge stuff and "FORGEDABOUDIT"!!;)

Marauderjack:bandit:

[magindat]

A side effect of this "Mod" is a bit more engine braking and much better exhaust "Burble"....Which I like!!:D

I would do it on my N/A car just for the 'side effect'. I like engine braking and 'burble'.

Thanx MJ. I printed your photo and intend to copy your mod.

[Loco1234]

If the this does increase braking and engine "Burble" due to the Hardware mod...

Will a software mod have the same or similar side effects?

[Dragcity]

I think Maraderjack always has helpful, positive tidbits to share with the group.

Wonder how that will sound with the 4" delete tips ????


Thanks Jack !!

[Power Surge]

Well, I wouldn't do this on my own car, but that's because I'm a tuner and can do it the proper way. If I didn't have that ability, I might give it a shot if it was needed.

Back in the 5.0 days, Ford had a "TSB plate" for the IAC on the 5.0. It was basically a bleed plate, that allowed more air in, to stop stalling issues on the 5.0 when the IAC would get clogged up on cars with lots of miles. The mod guys quickly found that this plate was also helpful for speed density cars that would stall with cams, and became a common mod. I had one on my Gen 1 Lightning for the same reason.

As for using it on the MM, I can see how it cuts down the flare up issue, as it makes less air bleed into the intake. However, I don't see how it's fixing a stalling issue, as I would think that would have to be the other way around (you'd need MORE air to combat a stalling issue).

I'd be curious to see the long term outcome is of this mod. There are a lot of IAC things in the calibration, that it's possible that over time it will either learn around the mod, or throw a code. The PCM is looking for certian reactions from the motor. Your plate is causing different reactions. The PCM will try to correct for that, just like if your IAC was dirty or whatnot.

I'm still a little confused on your stalling issue. The car shouldn't stall, unless something is not physically right, or you've changed something that drastically alters the idle air, like ported heads or cams. Just putting a blower on should not cause stalling, unless there is a mechanical issue, or the kit is of poor design.

[Marauderjack]

Stay tuned.....I'll report back as time goes on!!:beer:

If it throws a code or acts badly I can remove it in about 2 minutes....clear the code with the ScanGauge and be on my way!!:D

As far as idle speed stalling with a blower...ask Zack since he made the statement that "all blower cars have a tendency to stall"??:confused:

My ProCharger from Greg at FIT is a well designed kit and Scott Beer saw a few things he changed at idle. With the A/C on it hasn't stalled since Scot made his changes but with the vent only on.....IT WILL STALL!! BTW, my "in gear" idle is at 650 RPM's and probably should be bumped up some but I like it there and if the restrictor continues to work well....I'll leave it alone!!:rolleyes:

Marauderjack:D

[TooManyFords]

Well, I wouldn't do this on my own car, but that's because I'm a tuner and can do it the proper way. If I didn't have that ability, I might give it a shot if it was needed.

Back in the 5.0 days, Ford had a "TSB plate" for the IAC on the 5.0. It was basically a bleed plate, that allowed more air in, to stop stalling issues on the 5.0 when the IAC would get clogged up on cars with lots of miles. The mod guys quickly found that this plate was also helpful for speed density cars that would stall with cams, and became a common mod. I had one on my Gen 1 Lightning for the same reason.

As for using it on the MM, I can see how it cuts down the flare up issue, as it makes less air bleed into the intake. However, I don't see how it's fixing a stalling issue, as I would think that would have to be the other way around (you'd need MORE air to combat a stalling issue).

I'd be curious to see the long term outcome is of this mod. There are a lot of IAC things in the calibration, that it's possible that over time it will either learn around the mod, or throw a code. The PCM is looking for certian reactions from the motor. Your plate is causing different reactions. The PCM will try to correct for that, just like if your IAC was dirty or whatnot.

I'm still a little confused on your stalling issue. The car shouldn't stall, unless something is not physically right, or you've changed something that drastically alters the idle air, like ported heads or cams. Just putting a blower on should not cause stalling, unless there is a mechanical issue, or the kit is of poor design.

Well, I would love to find out how to tune around an extremely high idle because of my blower. I talked to the throttle body guy today who sets up the dual TB systems and explained my problem: It starts and idles right at 3500 and then drops down to 2500 and stays there. He told me to leave the iac settings alone in the tune and to build a restrictor plate to put underneath my IAC. Start with a very small hole and work my way up until it idled like it should. The way he explained it was that my blower is creating a lot more vacuum under the TB and that was the reason for the restrictor plate.

So, I'm not against this mod at all and I agree that it should not fix a stalling issue. But I'm open to try things in ProRacer to get it to idle without the restrictor plate. So far everything I've tried in there related to the IAC has done nothing to control it.

And just to be fair, I am going to use a can of ether tonight to see if I have a vacuum leak below the throttle bodies, just in case.

john

[Power Surge]

Well, I would love to find out how to tune around an extremely high idle because of my blower. I talked to the throttle body guy today who sets up the dual TB systems and explained my problem: It starts and idles right at 3500 and then drops down to 2500 and stays there. He told me to leave the iac settings alone in the tune and to build a restrictor plate to put underneath my IAC. Start with a very small hole and work my way up until it idled like it should. The way he explained it was that my blower is creating a lot more vacuum under the TB and that was the reason for the restrictor plate.

So, I'm not against this mod at all and I agree that it should not fix a stalling issue. But I'm open to try things in ProRacer to get it to idle without the restrictor plate. So far everything I've tried in there related to the IAC has done nothing to control it.

And just to be fair, I am going to use a can of ether tonight to see if I have a vacuum leak below the throttle bodies, just in case.

john

Hehe, well your car in kind of in it's own catagory, as far as things that may or may not need to be done. Because of the size of the blower, you might be better starting off trying a mechanical fix, because your setup physically just may be too much to fix with a tune. I have a lot of experiance with it, but I can admit that trying to tune idle air via mail order is a big PITA.

[Marauderjack]

John,

I think part of my stalling has to do with my idle being at 650 RPM's in gear......I like the way it sounds and would like to stay in that range if possible??

Dave sets the "Blower Tune" idle speed at 900 RPM's in gear and it lunges at stops when the AC compressor kicks in!!!:argue: So.....I'm sure part of the stalling is my preference and not the car or the tune??:confused:

The restrictor is very easy to make and would tell you in an hour or less if you could control your idle speed by this method......for that matter you can just take the IAC valve off and put a piece of duct tape over the openings and see what it does.....Give it a shot!!;)

Meanwhile I will continue ruining my engine or my EEC with this "Mickey Mouse" mod!!:shake:

Honestly...I cannot see what it can hurt and the thousands of "Mustang Guys" who have tried crazy stuff have said it works for them........'Nuf said!!

Marauderjack:shake:

[TooManyFords]

John,

I think part of my stalling has to do with my idle being at 650 RPM's in gear......I like the way it sounds and would like to stay in that range if possible??

Dave sets the "Blower Tune" idle speed at 900 RPM's in gear and it lunges at stops when the AC compressor kicks in!!!:argue: So.....I'm sure part of the stalling is my preference and not the car or the tune??:confused:

The restrictor is very easy to make and would tell you in an hour or less if you could control your idle speed by this method......for that matter you can just take the IAC valve off and put a piece of duct tape over the openings and see what it does.....Give it a shot!!;)

Meanwhile I will continue ruining my engine or my EEC with this "Mickey Mouse" mod!!:shake:

Honestly...I cannot see what it can hurt and the thousands of "Mustang Guys" who have tried crazy stuff have said it works for them........'Nuf said!!

Marauderjack:shake:

Don't get me wrong, I think the fix has a place in the world and mine seems to maybe be the exception to the rule. I also may have been misinterpreted above about costs. I'm sure most, if not all, tuners supply free upgrades to fix these types of things. The point I was trying to make was that this is all well and good for those out there that have actually bought a tuner and tunes from someone. But for someone who does not have these tools, a free upgrade just isn't really free and more on the order of $300 instead of a buck fifty for the restrictor fix.

And certainly this fix is not like the days of old where someone would get a new vehicle home and then rip all the emissions hoses off and cap them thinking this was the correct fix. Capping off lines is not the same thing as slowing down a reaction (ala the restrictor plate).

You'd be surprised just how may garage mechanic fixes like this end up as engineering TSB's or part upgrades later.

John

[JohnE]

My car developed a stalling issue recently. After a bit of troubleshooting, the culprit was found. The diaphragm of the blower bypass actuator had failed. It was doing two things bad: 1) vacuum leak & 2) no bypass (spring-loaded closed)

If you do not have a vacuum leak and/or a blower bypass on a PD blower you'll have problems. This can be tuned around, but better to properly fix.


At idle, the PCM learns Idle Air Control biases. Over time, an orifice may cause you problems. While cruising down the road, the IAC valve is held open, based on MPH & RPM. It is held ready for sudden release of the accelerator and possibly a hit of the brake. By restricting the flow, you may create a tendency to stall under certain situations.




Good Luck,

JohnE

[Marauderjack]

I checked all of that John.....All functioning well.....Thanks for the "Heads Up"....I'll continue my restrictor trial and report back....GOOD or BAD!!:bandit:

Marauderjack:burnout:

[snowbird]

Marauderjack,

I have tried a 600-650 rpm idle early this summer and it was also stalling. Just made Lidio bump the idle 100-125 rpm to 700 something. Since then no more stalling. And as you know, our mutual setup are pretty much the same.

I think it was simply too low ==> one more accessory: the blower, longer intake track so the computer is lagging his corrections, i don't know. Mine was stalling in slow 5 to 10 mph curve in heavy traffic or at a stoplight. In the curves, it was dangerous as i had instant "no more power steering" and almost no brakes. Not a good combo with 4300 lbs. 700 something is not that high an idle when you see big cam old school cars idling over 1000 - 1100 ...

My 02 cents in CDN currency !:)

[TooManyFords]

I am happy to report that mine now idles really close to what I'm commanding. It starts at 1800 and then settles down to 1100 and purrs like a kitten... a very, Very ANGRY kitten!

In gear it holds a perfect 900 with no surges. My restrictor plate has a 1/8" hole on the engine side of the IAC.

I'm sure that once I get the LTFT and STFT's data logged I can tweak it down further. At least I'm in the ballpark now.

John

[SergntMac]

Mac,

A number of owners have disliked the 2000 RPM "Flare" on cold startup.....including me but my main reason for trying it was stalling while idling without the A/C running!!:argue:

Zack said at one point that all S/C cars have stalling issues!!??:confused:

I had Scott Beer modify my Diablo Blower tune and it helped a bunch but still had stalling every once in awhile without the A/C running??:confused:

This restrictor seems to have fixed it completely and I just though I'd share it with the rest of you.....FWIW!!:shake:

A side effect of this "Mod" is a bit more engine braking and much better exhaust "Burble"....Which I like!!:D

The "Mustang Guys" especially like it with their straight drive cars since the exhaust sounds "Old School" without the RPM's "Hanging" between shifts!!:bows:

That's all........;)

Marauderjack:pimp:Thanks!

Just asking if it's "problem solving" or a "performance mod" so I know where to store the link.

Yep...Zack and I had a lot of "blower side effects" to work out back in 2003, and we had a similar problem. Stalling in low cruise/slow traffic, and on turns were the chief problems. As I recall it now, 1) the blow off valve was dirty, then later broken, and 2) Jerry made some adjustments in the tune, all gone.

Good luck with your project!

[Marauderjack]

WAY TO GO JOHN!!!:beer:

I'm glad that something GOOD came from this thread!!:cool:

Marauderjack:bandit:

[Haggis]

Interesting mod Jack, will be keeping my eye on this thread.

[RCSignals]

Interesting mod Jack, will be keeping my eye on this thread.

uh oh, that's rather ominous...

[SergntMac]

Don't get me wrong, I think the fix has a place in the world and mine seems to maybe be the exception to the rule. I also may have been misinterpreted above about costs. I'm sure most, if not all, tuners supply free upgrades to fix these types of things. The point I was trying to make was that this is all well and good for those out there that have actually bought a tuner and tunes from someone. But for someone who does not have these tools, a free upgrade just isn't really free and more on the order of $300 instead of a buck fifty for the restrictor fix.

And certainly this fix is not like the days of old where someone would get a new vehicle home and then rip all the emissions hoses off and cap them thinking this was the correct fix. Capping off lines is not the same thing as slowing down a reaction (ala the restrictor plate).

You'd be surprised just how may garage mechanic fixes like this end up as engineering TSB's or part upgrades later.

JohnThis is true, seems like the "beta" testing never ends. But, for those without mods? Anyone who hasn't bought a tuner should be problem free, rght? Or, is this stalling more widespread among stock Marauders than I am reading about?

My #3 MM has an off-the-helf SCT tune for CRD1, and it doesn't stall, anytime. If it did, I would suspect the tune was at fault before considering another mod such as a restrictor plate. Seems only logical to me.

The "rule of thumb" is that one mod leads to another", any projection on "side effects" from the restrictor plate?

[Marauderjack]

My Marauder.....BRAND NEW....factory tune....STALLED the first day I had it!!!:argue: I was on an incline and it re-started right away but did it several times after that until I got the SCT tune??:beer:

I thought I made it clear.....For whatever reason it has not stalled WITH THE A/C ON....it only stalled with the VENT on....so I don't think the average guy would care since most run with the HVAC in the "AUTO" position only??:cool4:

I could probably bump the idle up 100-150 RPM's but I like it where it is at 650 in gear!!:bows: The nice "Burble" on deceleration and not creeping forward at stops!!:cool:

I drove the car almost 700 miles so far this week and it has not stalled once....NO CEL....Runs perfectly with minimal "Flare" on cold start falling almost instantly from 1600 RPM's (used to go to 2000++ cold and hold there for several seconds....can't be good!) to about 1000-1100 RPM's in "Open Loop" while it warms up!!;)

I am leaving it alone for now and will report back in a few days!!:bandit:

Marauderjack:D

[Marauderjack]

I have noticed that cold starts rev only to about 1500 and drop back to 1000 almost instantly!! That cold idle is rock solid in Open Loop and drops back to my pre-set idle speed of 650 when it goes into Closed Loop!!:beer:

Note: As mentioned before cold starts used to "Flare" to 2000++ or so and gradually fall back to 1200 over 5-10 seconds.

Warm starts rev to 1600-1700 and fall back within half a second or so....No Check Engine Light yet!!:bows:

Stay tuned!!

Marauderjack:D

[Marauderjack]

UPDATE!!!:cool:

Well,

I have noticed that at idle there is a distinct "Putt...Putt...Putt" that is not part of the normal exhaust tone??:confused: :shake: Increasing engine speed to 1500-2000 RPM's also increased the noise to even sound like a missfire!!:argue:

I removed the restrictor and tried again......NOISE GONE!!:beer: The Mustang guys said to start with a 9/32" hole and open it up if there are any abnormal side effects....so I opened it to 13/32" and the "Putt...Putt...Putt" is gone!!:bows:

All I can figure is the idle mixture was a bit rich and unburned fuel was igniting in the exhaust?? What is puzzling is that it was still there "Off Idle" BUT the IAC should not be involved above idle speeds??:confused:

I will run it for a couple more days with the larger hole and report my findings!!

So far all it does is allow the engine to return to idle much faster.....reduce start-up "Flare".....give a nice rumbling "Burble" on deceleration!!!:beer: NO IMPROVEMENT in fuel mileage but no loss either!!:bows:

Stay tuned!!

Marauderjack:burnout:

[Haggis]

UPDATE!!!:cool:

Well,

I have noticed that at idle there is a distinct "Putt...Putt...Put" that is not part of the normal exhaust tone??:confused: :shake: Increasing engine speed to 1500-2000 RPM's also increased the noise to even sound like a missfire!!:argue:

I removed the restrictor and tried again......NOISE GONE!!:beer: The Mustang guys said to start with a 9/32" hole and open it up if there are any abnormal side effects....so I opened it to 13/32" and the "Putt...Putt...Putt" is gone!!:bows:

All I can figure is the idle mixture was a bit rich and unburned fuel was igniting in the exhaust?? What is puzzling is that it was still there "Off Idle" BUT the IAC should not be involved above idle speeds??:confused:

I will run it for a couple more days with the larger hole and report my findings!!

So far all it does is allow the engine to return to idle much faster.....reduce start-up "Flare".....give a nice rumbling "Burble" on deceleration!!!:beer: NO IMPROVEMENT in fuel mileage but no loss either!!:bows:

Stay tuned!!

Marauderjack:burnout:

Sounds good so far Jack and thanks for being a guinea pig with this mod.

[magindat]

Hey y'all. I tried this on an NA car. Just curious to see if the 'side effects' were worth it. I like engine braking and the sound of it as well as the control.

I had 3 problems.
First, the car learned to stall.
Second, It would not downshift into first when stopping. A few seconds after the full and complete stop, the car would then shift into first wnd jerk a bit.
Third, it would upshift when lifting off for a turn. Then it had no power for an apex exit (too high of a gear) and if pedalled enough, the downshift makes for a dangerous drift possibility.

So, all in all, the slight engine braking benefit wasn't worth it. Don't flame me or tell me I shouldn't have done it or any other crap. I don't wanna hear it. I experiemnted. I learned. I didn't damage the car and I shared my expereince. Just say thanks.

Thanx for the idea.

BTW, If anyone wants to try a plate and making it is tough for you, PM me and I'll send ya mine in the mail no charge.

[Marauderjack]

magindat....

WOW.....All that from the IAC valve?? My "Putt...Putt" sound was off idle too which leads me to believe the IAC plays a more important role than just idle control??:confused:

I got a bit of idle "hunting" today when idling so when I got home I disconnected the battery for a few minutes. When re-connected and I started the car the "Flare" was at 2000+ and took about 10 seconds to settle down to idle......then the A/C kicked in and the idle went to 1500 RPM's!!??:eek:

I'll have to drive it some tomorrow to let the "AL" come back.....Stay tuned!!:cool:

Marauderjack:bandit:

[Marauderjack]

Please note:

If making changes to the restrictor it is necessary to disconnect the battery for a few minutes and allow "Adaptive Learning" to be reset otherwise your results can get a little crazy!!:cool:

I my case it takes a couple days for my car to re-learn and settle down??:cool4:

This "Mod" if that's what you call it, has no real advantage except reducing cold start "flare" and give you a bit more exhaust "burble".....I cannot see any other advantages or disadvantages resulting from it!!:shake:

Marauderjack:burnout:

[MarauderMark]

This was a good thread to read so far.Thank you gentlemen:up:

[Power Surge]

I told ya there would be side affects ;). The IAC is a very complex thing on newer Fords. The PCM has a specfic transfer function for it (just like a MAF). If you go messing with it the PCM will try to correct around it, as it's programmed to do, so that as time goes on and the IAC starts working different from carbon buildup and such, the motor runs the same. And if the PCM can't get the control it wants from the IAC duty cycle itself, it starts altering the fuel and spark tables. The putt putt you were feeling is most likely the altered idle spark the PCM is attempting to fight the restrictor plate with.

[Marauderjack]

Sal,

I'll have to agree with you......

The restrictor does allow the engine RPM's to drop quicker as when shifting a 5-speed but my observations so far indicate the EEC IS TRYING to compensate for the lack of available air from the IAC??!!:confused: This may account for the "Off Idle" roughness or "Putt..Putt" in the exhaust??:cool:

I'm going to leave it on another week then take it off and check mileage and pay attention to idle and exhaust sounds......of course after I reset the AL by disconnecting the battery!!:bandit:

Stay Tuned!!

Marauderjack:burnout:

[magindat]

I'm not a tuner.

It seems to me the IAC plate did all of it's deeds in the transmission department. As if the PCM wasn't getting the right info to shift (esp downshift) properly.

I did get a lower and quicker startup flare. So that was OK.

I think if the Marauder was manual and SC, the benefits would outweigh the side effects. I could see the notion of restricting the air flow in IAC esp on startup flare since the SC is pushing in more air at that moment of 2K rpm startup than the IAC or PCM is made/programmed. If this issue is tunable, perhaps many tuners over look it? (no flames, just thinking out loud)

In any event, most of the problem was bad info for the tranny to operate off of.


This has been one of the most educational threads in a long time.
Thanx

[Vortech347]

Our 01 SVT has this problem. BAD. It hangs when you shift, I hate it. It can be tuned out but our local guy that did the SCT programs I don't think quite understands how to tune it out. He tried a different tune but the car idled at 3000rpm. Opps. I'll most likely get a spacer.

[magindat]

Our 01 SVT has this problem. BAD. It hangs when you shift, I hate it. It can be tuned out but our local guy that did the SCT programs I don't think quite understands how to tune it out. He tried a different tune but the car idled at 3000rpm. Opps. I'll most likely get a spacer.
I could send you my plate, if you wanna try it. PM me an address. No charge.

[MitchB]

Controlling start-up engine speed is a little tricky. I have made many calibration changes with follow-up datalogs of my cold starts. I've been able to get my cold start max engine speed on initial start-up down to around 1400 - 1500 momentary RPM with an immediate drop to just below 1000 RPM. The large intake manifold volume makes controlling start-up speed difficult. There are start-up airflow calibrations you can play with, but most important is how much fuel you put into the engine while cranking and lowering spark when the engine fires as you exit the cranking event. This plus a few other tweaks here and there. Not too many people are concerned with this or know what to do...

Mitch

[Marauderjack]

Well Folks,

After about a month of experimenting I removed the "Restrictor" and reset the AL by disconnecting the battery!!:cool:

The "Flare" with the AL reset is crazy.....2000+RPM's and hangs at about 1500 for 5-10 seconds!!!:argue: From past experience it will take a few days to "Re-learn" the idle characteristics and settle down??:o

I'll report back after it settles down but for now I'll have to agree with the concensus....The AL feature of our EEC's attempts to compensate for the restrictor and I feel it is better to leave it alone.....FWIW!!??:eek:

A "Mod" not worth doing with an automatic trans!!:shake:

Nitrous SSC....I will send you mine to try if you like??

Marauderjack:pimp:

[magindat]

Got your PM, Nitrous.
Will mail tomorrow.
Good luck with it!
Rich