how do i adjust RPM?

[Dr.Sound]

i know there is a screw....but where?

[KzA]

you mean idle rpm? Its on the lower right hand side of the throttle body...

Using search will yield some pics..

[Dr.Sound]

cant find pics, just read through 10 threads.
can anyone post them? or explain where it is.

thanks.

[KzA]

cant find pics, just read through 10 threads.
can anyone post them? or explain where it is.

thanks.

http://www.msprotege.com/forum/showthread.php?t=91817&highlight=idle+screw+pic

That should help...its basically the screw attached to the throttle body cable linkage...

[blthlt]

I dont have a pic but if you look where the throttle cable attaches and follow that down you'll see the phillips head screw just below it. The screw head is facing the drives side.

[vindication]

wasn't there something about the ECU "learning" and then reseting the idler to it's stock idle?

[KzA]

well...There is no way it could reset the screw, but maybe by adjusting air fuel ratios at that rpm range it deals with the issue..I'm not too sure this is the case though becuase I know alot of people with turbo setups were using this method of altering the idle...something to look into definately, though

[vindication]

well obviously it doesn't adjust the screw but does something else. not sure what but I dont feel like looking it up now

[BlkZoomZoom]

IAC.... Idle air control

Most aftermarket turbo kits use a engine management that takes away the pcm memory function, not allowing it to learn around things. If you had a WDS you can adjust it through the pcm.... but I don't think you have one.

[ChopstickHero]

^^^
so are you saying that the IAC in the MSP will control the idle, so adjusting the screw won't work as a long term solution?

at stock, i was idling a perfect 700-800 rpms. after my mods, i am idling 400-500rpm.

[Dr.Sound]

hey mike, same here.
i think it's the turbohoses IC.
does you car vibrate more?

i dont get sperratic idle, it's constant, but just lower than before......and with AWR front motor mount i get masage at every red light.

[ZenProtege]

doesn't the IAC work by using a controled a vac leak to maintain idle?

drsound-when I put my front mount and exhaust on it did the same thing

[Dr.Sound]

i had my motor mount and exhaust for a while.
but after i put the IC and s-pipe the car started shaking more....

[peepsalot]

doesn't the IAC work by using a controled a vac leak to maintain idle?

drsound-when I put my front mount and exhaust on it did the same thing
The IAC is a computer controled solenoid valve that allows some small amount of air to bypass the throttle body even when it is completely closed. This is how the car is able to have a high rpm cold start idle for example.

[ZenProtege]

I'm going out on a limb here,

For the longest time my msp has pulled some crazy strong engine vac. I usually pull 23-25 inches or .70-.74 KPA of vac. (I have 2 boost guages, so I know its not the guage). I'm curios if the IAC not being open(or out of whatever position it should be) is causing an increase in vac and low idle. my car will pull the same vac at 500 & 900 rpms which makes me think it might be gunked up and unable to function like it should at idle. I've always heard of not enough vac being a problem but never too much

[peepsalot]

Yeah the IAC can definitely affect your vacuum. When you turn on your A/C for example, you should see less vac because the IAC has to open even more to provide enough extra power to run the compressor. If your IAC was stuck I think your engine would be stalling much more. Are you actually having idling problems?

You can try removing the IAC and cleaning it out if you are convinced it is causing problems. I did it to mine once, although I found it was pretty clean to begin with, and it wasn't what was causing my problems. It's the solenoind that is on the throttle body, and it is easy to take off. After it is off, to take it apart you need some special screw drivers, but I just used needle nose vice grips instead.

BTW that vac doesn't sound too crazy, I think I get about 23 with A/C off at idle.

Also, coasting while in gear will give you a very high vac and that is normal.

[ZenProtege]

The idle problems, when I get them, are very hard to pinpoint. I can drive a week and idle perfect, well if you can call 500 rpms perfect :( . Occasionaly it will choose a day to start freaking out and idling like I just stalled from blowing off to atmosphere. I get the usual drop to zero bounce to 1000 rpms until it catches up; typically when gearing down from 3rd or 4th but sometimes while sitting in traffic.
Other times at idle the rpms will randomly drop to 100 for a second and then go back up to normal. Sometimes this will happen a few times in a row but it always settles back to normal before it drops again unlike the first described
Nothing is ever consistant enough for me to diagnose nor can find a consistant situation that causes it. It's not a major problem but rather an occasional nuisance.

[BlkZoomZoom]

I would bet more on an innacurate vacuum gauge. I don't know how many times I tell people not to install the intakes on these cars. The Maf sensor was designed to read airflow delivered from the stock airbox, not some differently shaped tubes.

[ZenProtege]

I have 2 boost gauges, one reads vac in in/hg the other in kpa's and both read the same. I currently have the maf on the pressure side and have had no change in vac compared to intake side. why do you think the maf can't handle a sri or cai?

[Dr.Sound]

I would bet more on an innacurate vacuum gauge. I don't know how many times I tell people not to install the intakes on these cars. The Maf sensor was designed to read airflow delivered from the stock airbox, not some differently shaped tubes.
please elaborate on this.
i respect your knowledge blkzoomzoom, i'm just trying to learn as much as i can myself.

my orange MSP did run better with the stock box....but that was before the flash.
granted flash did nothing for air flow, but the car with a CAI does seem to run better with the flash.

tell me, is stock air box with K&N filter better than a CAI?

[vindication]

use the stock airbox with the pipes from the CAI or buy other pipes to make it work. that way the sucky stock pipes that will expand under high boost wont expand and you still have the airbox.

[low_psi]

You're not going to expand the stock intake pipe, it is never pressurized.

[vindication]

heheh, I forgot, thats what I get for offereng advice 10 min after I wake up

[Brian MP5T]

wasn't there something about the ECU "learning" and then reseting the idler to it's stock idle?

Yes, The workshop manual states that this should never be altered, it is factory set and whatever problem is there will simply be re-learned and adjusted bring back the same situation. Fix the route of the problem, IE the auto adjuster...

[Brian MP5T]

well obviously it doesn't adjust the screw but does something else. not sure what but I dont feel like looking it up now

It's a small stepper motor attached to a second small "throttle body" that varies to maintain a constant Rev when the throttle is closed (With Throttle Position sensor) It's intergrated into the throttle body and can only be adjusted electronically.

[peepsalot]

Yeah I wonder why that screw even exists or is set to anything in the first place, since the IAC should be able to complretely control the idle.

[vindication]

good looks bri

[BlkZoomZoom]

Yeah I wonder why that screw even exists or is set to anything in the first place, since the IAC should be able to complretely control the idle.

That screw works and you can set the base idle to whatever you want without the pcm trying to re-learn if you complete the entire procedure. In which you guys (no offense) don't know how to do or have the equipment to do so. Like I said before.

And yes I would use the stock airbox over a CAI or SRI anyday of the week. If your not going to go past its flow limits than why would you replace it? I have never experienced any car that actually ran correctly with any CAI or SRI.

[BOOSTR]

What about the timing? If its off wouldn't that cause low RPMS and a dipping idle?

[BlkZoomZoom]

Also a cel.

[Brian MP5T]

What about the timing? If its off wouldn't that cause low RPMS and a dipping idle?

Timing, as in the belt jumped a tooth?

[BOOSTR]

No, I was refering to incorrect ignition timing.

[Brian MP5T]

No, I was refering to incorrect ignition timing.

That could only truly happen if the cam and/or Crank position sensor was somehow off..

It would trigger a CEL...

[ZenProtege]

And yes I would use the stock airbox over a CAI or SRI anyday of the week. If your not going to go past its flow limits than why would you replace it? I have never experienced any car that actually ran correctly with any CAI or SRI.

Because the rate, not the limit, that air can flow is increased from a CAI/SRI . If the intake turbine is able to suck in air quicker with the least possible resistance why wouldn't there be a gain. We replace our stock exhaust well before its flow limits are maxed out in the same regards as intakes.
You have a high pressure system quickly feeding to a low pressure on the exhaust end of the turbo. You have the opposite on the intake side w/ a low pressure system feeding a high pressure. Why would there be a gain from increasing the flow limit/rate on the exhaust end of things and not the intake?


the
I don't know how many times I tell people not to install the intakes on these cars. The Maf sensor was designed to read airflow delivered from the stock airbox, not some differently shaped tubes.

I strongly agree, but don't we have a map sensor the ecu refences to make sure the maf is reading right. The maf sensor must not be too picky about how it reads air or else relocating it would be a disaster wouldn't it?

[ZenProtege]

I'll be heading to the dyno this weekend and I will put my SRI up against the Stocker @ 8psi. If your right i'll throw the SRI in the garbage and put the stock back on for good

[Dr.Sound]

^ please let us know how it turns out. i'm curious.

[BlkZoomZoom]

Because the rate, not the limit, that air can flow is increased from a CAI/SRI . If the intake turbine is able to suck in air quicker with the least possible resistance why wouldn't there be a gain. We replace our stock exhaust well before its flow limits are maxed out in the same regards as intakes.
You have a high pressure system quickly feeding to a low pressure on the exhaust end of the turbo. You have the opposite on the intake side w/ a low pressure system feeding a high pressure. Why would there be a gain from increasing the flow limit/rate on the exhaust end of things and not the intake?


the

I strongly agree, but don't we have a map sensor the ecu refences to make sure the maf is reading right. The maf sensor must not be too picky about how it reads air or else relocating it would be a disaster wouldn't it?


Let me know how much you actually gain, from personal experience it is not worth it at all.

Yes we have a Map sensor. No it doesn't work like that, not really. The map sensor is basically an emissions system monitor. It only has something to do with a/f in certain situations and is never a direct effect. I've never ridden in a car with the Maf sensor on the hot-side pipe, but I garuntee you I wouldn't be happy with it.

[ZenProtege]

So the if the maf steadily saw 130 lb/min of airflow and outputed that to the ecu, and at the same time the map was reading some pressure equal to 110 lb/min and sending it to an emissions module or whatever we have, the pcm wouldn't pick up on the difference & wonder whats up?
I agree on the maf thing being a weird solution but I first hand know that it works well and improves drivability spite the major difference in location. The maf must be reading crazy between full boost shifts when a ton of air gets remeterered past the maf on its way out to the BOV(my only guess has been the TPS says the amount of airflow the maf is reading isn't possible bc the throttle is closed so the maf gets ignored).
Further on that is what the ecu thinks in response to having the maf read instantly and accurately. There has to be some kind of time lapse the ecu expects before the metered air actually gets thrown in the cylinder. In that same respect a lapse for when recircualted air should get thrown in too.

[genius]

Are you getting tiny backfires at idle? If so check your plugs, they may be sooty. That will cause erratic idle.

There is also the EGR calve located under the TB. Some people ahve said that cleaning it helps. I personnaly never bothered with it, the erratic idle reminds me of how those old V8 engines would go glug... glug.... ..... glug... LMAO!!!!

Now if only it was deeper!

Anyways, I wouldn't bother adjusting that screw, your PCM will see the idle signal go up and back it down within a few days.

If we took a poll, I think you owuld find that probably 40% are experiencing the same thing. Just ignore it and it will go away!

Mine went away after I upgraded my SMIC. When I did that I also replaced all my vacs and T's. RIght away I noticed my vac went down to -22 from -19 and it idles perfect. Guess I had a vac leak, not really sure though.

[genius]

i know there is a screw....but where?
Are you getting tiny backfires at idle? If so check your plugs, they may be sooty. That will cause erratic idle.

There is also the EGR calve located under the TB. Some people ahve said that cleaning it helps. I personnaly never bothered with it, the erratic idle reminds me of how those old V8 engines would go glug... glug.... ..... glug... LMAO!!!!

Now if only it was deeper!

Anyways, I wouldn't bother adjusting that screw, your PCM will see the idle signal go up and back it down within a few days.

If we took a poll, I think you would find that probably 40% are experiencing the same thing. Just ignore it and it will go away!

Mine went away after I upgraded my SMIC. When I did that I also replaced all my vacs and T's. RIght away I noticed my vac went down to -22 from -19 and it idles perfect. Guess I had a vac leak, not really sure though.

[genius]

So the if the maf steadily saw 130 lb/min of airflow and outputed that to the ecu, and at the same time the map was reading some pressure equal to 110 lb/min and sending it to an emissions module or whatever we have, the pcm wouldn't pick up on the difference & wonder whats up?
I agree on the maf thing being a weird solution but I first hand know that it works well and improves drivability spite the major difference in location. The maf must be reading crazy between full boost shifts when a ton of air gets remeterered past the maf on its way out to the BOV(my only guess has been the TPS says the amount of airflow the maf is reading isn't possible bc the throttle is closed so the maf gets ignored).
Further on that is what the ecu thinks in response to having the maf read instantly and accurately. There has to be some kind of time lapse the ecu expects before the metered air actually gets thrown in the cylinder. In that same respect a lapse for when recircualted air should get thrown in too.

This theory is hard to grasp. It took me a while anyways.

The MAF and PCM don't care whether it is on the front of the turbo or on the back. What ever the turbo blasts out it has to suck in. Air isn't created, just transferred. There will be just as much air moving and getting tossed around at the intake as there will be on the pressure side.

As for the craziness you describe (LOL!), the diffuser breaks it up regardless. As long as it is there, the whirling motion will be straighten out for the wind vane. Also, with the MAF in the other position, the recirc is irrelevant. You would be better off blowing it out altogther (BOV).

[Dr.Sound]

nahh, not getting backfires.
just replaced my plugs.....had them in since april and they looked almost brand new.

my idle went down after i installed SMIC.
i dont know if it went down actually......my car just vibrates more at idle.....maybe it did go down by like 100 rpm (stock gauge is not acurate enough to show that).

[wicked]

Let me know how much you actually gain, from personal experience it is not worth it at all.

Yes we have a Map sensor. No it doesn't work like that, not really. The map sensor is basically an emissions system monitor. It only has something to do with a/f in certain situations and is never a direct effect. I've never ridden in a car with the Maf sensor on the hot-side pipe, but I garuntee you I wouldn't be happy with it.

your starting to bug me a bit on this.
I am not sure,but you sound like a mazda tech much more then you sound like a performance enthusiest,or a performance tech.
especially on the last portion of this comment"I've never ridden in a car with the MAF sensor on the hot-side pipe,but I garuntee you I wouldn't be happy with it"
you are thinking VERY close minded.fact is just because something is designed for one thing,and to work one way does not mean it cannot be used in other ways,or altered to do other things.(something you already know)
if it weren't for the MAF maxing out so quikely,and contaminating so easily,then most manufacturer would most likely be putting them on the preasure side.it read VERY accurately what is going into the engine.

I bet you would be rather pleased with driving a MSP with a moved MAF as long as the person took the right precations to tune for it.

[BlkZoomZoom]

your starting to bug me a bit on this.
I am not sure,but you sound like a mazda tech much more then you sound like a performance enthusiest,or a performance tech.
especially on the last portion of this comment"I've never ridden in a car with the MAF sensor on the hot-side pipe,but I garuntee you I wouldn't be happy with it"
you are thinking VERY close minded.fact is just because something is designed for one thing,and to work one way does not mean it cannot be used in other ways,or altered to do other things.(something you already know)
if it weren't for the MAF maxing out so quikely,and contaminating so easily,then most manufacturer would most likely be putting them on the preasure side.it read VERY accurately what is going into the engine.

I bet you would be rather pleased with driving a MSP with a moved MAF as long as the person took the right precations to tune for it.

I have been and always be a Mazda tech over a Performance tech. If the car does not retain the stock driveabilty I WILL not be happy. If you can tune for it than I am happy. It doesn't matter what car and what mod. If you have to make sacrafices of driveability than its not worth it.

[wicked]

my car if forged8.5 comp with a 4" intake relocated MAF,GT28RS MPI tuner.

and of all the things I have done to my car only one has negatively affected the enjoyment,or quality of the ride,that was the motor mounts.
everthing else has been positive.
moving the MAF is a noticable gain in throttle response,and quality of drivability and idle.
you are making a blind assumption,and stating that IT WORKS LIKE THIS,but you need to know that not everthing manufacturers have done is the best way of doing something,it's not all black and white,and MAF function has a gray area.it can be tricked,and it can be moved to be more accurate.

you cannot denie that it doesn't read air more accuratly when moved,the only thing you can say is it's ot designed for this application,and in doing the relocation you will cause it to read wrong.

but it's not true.it it were able to have a higher voltage limit,then yes.but the reason it works so well is because it maxxes out it's voltage limit when going to boost,so it can make any changes in that area.

it does however run abit leaner here,due to it now correctly reading the air coming trough.this is takin care of by the shortterm,and is such a little difference that it dosen't even affect the long term FT(hence no cell)

[wicked]

BTW,the reason you have such a good 1/4 mile time is not because you were able to set your car up right,it's because you had power and the amount of time you spent on the track with it.
me,and a number of other members can easily beat that time if we invested as much track time as you have.
my car has been to the track once,it ran a 15.2,completely stock w/ stock boost at 4.8 PSI. and a ambient air temp of 90 deg out side.