Possible cold start fix

[ms3blackmica]

In the past, I have tried lowering the commanded idle speed at low ECT's with zero luck as many of us have sure tried and put it off to lack of control.

I decided to make a more drastic change in the idle speed table by setting the entire ECT range to my desired operating temp idle speed. Why not?

No more 2000 RPM loud cold start ups! Instead I am seeing around ~1300-1400 (tach reads 100-200 rpm higher) on initial start and then coming right down to 800. I've tried this every morning for 3 days and so far it is working. It may take a little longer for the engine to warm up in colder temperatures but as of right now I am okay with the calm cold starts.

Can you guys try this out as well and report back?

Set Idle speed tables A & B the same and to your desired RPM.

Gen 1:



Gen 2:

Cold Start Fix? - YouTube

Cold Start Fix? - YouTube

[Say Chi Sin Lo]

I too have wondered why the car "freaks out" when it has to wake up...

But then again, what's wrong with the factory setting? Aside from being loud as s*** and having a 2,000rpm idle, what's wrong with the factory setting?

Also, not sure if you guys know this, but my 04 NA Mazda 3 has a fairly calm cold-start routine. RPM jumps to ~1,500 and it calms down in a matter of ~10-15seconds. The MS3 takes ~40seconds to hover around 1,250rpm. (I timed it)

[ms3blackmica]

Nothing is wrong with them. In fact, they are set up properly.

Many people just cannot deal with how loud their cars are specially if they live in an apartment complex and leave for work very early.

[Quigs]

I'll be giving this a try...mine doesn't hold at 2000 rpm for very long but it goes from like 1500 then bursts to 2000 then back down to 1250 and I'm sure my neighbors in the apartment complex don't like that sudden burst as I start the car for work at 6 AM haha.

[BigRedSpecial]

My neighbor has a shi'tzu that fucking barks relentlessly. His bedroom is directly adjacent my driveway. I love my 2000rpm cold starts.

[MZRSPEED]

If you apply pressure to the pedal, then release as soon as it cranks your car will idle just like a hot start. I've been doing it for a while now, since I deleted my muffler/cat.

There is a thread about it somewhere, that's how I learned.


Sent from my iPhone using Tapatalk 2

[ms3blackmica]

Yep I am aware of that trick.

I just want to know if this setting has the same effect on my car as it does on other models/years.

[Volcom8190]

my car literally would not start with the ported manifold and the big turbo. although my idle is set to stock values.

[ms3blackmica]

Originally Posted by Volcom8190 my car literally would not start with the ported manifold and the big turbo. although my idle is set to stock values.

Did you scale the MAF for a larger intake?

[Volcom8190]

Originally Posted by ms3blackmica Did you scale the MAF for a larger intake?

only thing i changed was the idle table, tune is +3%/-1% on calibration across entire curve.

[Agent_Orange]

Just gave this a try on my Gen2 and it seems to exhibit the same behavior as your car Nishan. RPM rises to 1500 then slowly falls.

Cold Start - YouTube

Cold Start - YouTube

[ms3blackmica]

Well that's better than 2k lol

Thanks for trying that out Matt.

[ms3blackmica]

Originally Posted by Volcom8190 only thing i changed was the idle table, tune is +3%/-1% on calibration across entire curve.

Oh so you set the idle tables the way that I posted in the OP and the car would not start?

Thanks for posting BTW. I know the table posted is not technically proper.

I am just testing.

[fivefingerdeathpunch]

Originally Posted by Agent_Orange Just gave this a try on my Gen2 and it seems to exhibit the same behavior as your car Nishan. RPM rises to 1500 then slowly falls. Cold Start - YouTube

volbeat ftw.


btw are your cars just that quiet or is 2k vs 1.5k really making that much of a difference? my car is much louder on cold start..

[Agent_Orange]

Originally Posted by fivefingerdeathpunch volbeat ftw. btw are your cars just that quiet or is 2k vs 1.5k really making that much of a difference? my car is much louder on cold start..

Well I'm still stock exhaust, once my downpipe goes on I bet it will be a bit louder.

[ms3blackmica]

The "Desired RPM" Monitor on my Dashhawk has always worked properly and this morning I referenced it to ECT while the car warmed up and there is some compensation being multiplied to my target RPM until a certain ECT is reached.

I was only able to start around 80*F but I wrote down the target RPM's at each ECT breakpoint to determine what the compensation is.

My next step is reduce my target RPM's by that compensation factor and see if that brings me directly to 800 RPM on a cold start.

[mxlplx71]

i always hold the pedal 1/4 way down and let off as soon as it fires, idels low no roaring to life

[ms3blackmica]

I have confirmed on my gen 1 that once the ECT has reached 106*F there are zero compensations applied to the RPM targets in the idle speed table.

Will have to wait until morning to test more on cold start compensations.

I have confirmed on my gen 1 that once the ECT has reached 106*F there are zero compensations applied to the RPM targets in the idle speed table.

Will have to wait until morning to test more on cold start compensations.

[blackms3_71]

I like the idea, you had said that there is nothing wrong with the stock values so when does mazda have it set to 2k? Vs say normal 800 on cold starts? Just to warm the motor a little quicker?

[blackms3_71]

Originally Posted by ms3blackmica I have confirmed on my gen 1 that once the ECT has reached 106*F there are zero compensations applied to the RPM targets in the idle speed table. Will have to wait until morning to test more on cold start compensations. I have confirmed on my gen 1 that once the ECT has reached 106*F there are zero compensations applied to the RPM targets in the idle speed table. Will have to wait until morning to test more on cold start compensations.

Hey i went ahead and did the same changes to my map. I have a 08 ms3. I changed tables A&B to 800 rpm across the whole table like you. Anddd it WORKED!! Car started up to about 1500 rpm and according to the ap the ect was 84 degrees. I made a video but i dont know how to upload it from my phone. Thanks bro it was so nice for the car to start up "normal" and not loud as hell.

[Say Chi Sin Lo]

Originally Posted by blackms3_71 I like the idea, you had said that there is nothing wrong with the stock values so when does mazda have it set to 2k? Vs say normal 800 on cold starts? Just to warm the motor a little quicker?

I'd like to know too. Because I've always associated my cold starts with this:

[blackms3_71]

Originally Posted by Say Chi Sin Lo I'd like to know too. Because I've always associated my cold starts with this:

Lol

[BigRedSpecial]

HA! Exactly what mine is like. Then 30 seconds later he settles down for a cup of tea.

[blackms3_71]

It was nice to start the car this morning and it wasnt loud what a change that makes

[ms3blackmica]

As previously mentioned, I discovered that there was an obvious compensation being applied to the target RPM's in the idle speed table up until ~104*F.

I could spend the next 2 weeks plotting graphs to figure out the compensation applied but IMO Cobb should release these controls to us. It appears to simply be an RPM compensation referenced by engine coolant temperature. I have seen such compensation tables before in other PCM's and standalones.

I decided to make a much more drastic change to the idle speed targets near my cold start temperatures to counteract the compensation and sure enough I am now getting a desired idle speed of about ~1300 RPM on cold start.

Cold Start Test 3 - YouTube

Cold Start Test 3 - YouTube

[blackms3_71]

Originally Posted by ms3blackmica As previously mentioned, I discovered that there was an obvious compensation being applied to the target RPM's in the idle speed table up until ~104*F. I could spend the next 2 weeks plotting graphs to figure out the compensation applied but IMO Cobb should release these controls to us. It appears to simply be an RPM compensation referenced by engine coolant temperature. I have seen such compensation tables before in other PCM's and standalones. I decided to make a much more drastic change to the idle speed targets near my cold start temperatures to counteract the compensation and sure enough I am now getting a desired idle speed of about ~1300 RPM on cold start. Cold Start Test 3 - YouTube

I can try that too if you like to have a 2nd reference, at 800 rpm set in the a&b table my cold starts is about 1500 rpms so now that you changed it to 350 rpms(lol) you are seeinf only a 200 rpm decrease? cobb should give us those tables.

oh and I had a question for you. my tables shows temps in Celsius not in Fahrenheit how do I change that I didn't see a option in any menu

[ms3blackmica]

Originally Posted by blackms3_71 I can try that too if you like to have a 2nd reference, at 800 rpm set in the a&b table my cold starts is about 1500 rpms so now that you changed it to 350 rpms(lol) you are seeinf only a 200 rpm decrease? cobb should give us those tables. oh and I had a question for you. my tables shows temps in Celsius not in Fahrenheit how do I change that I didn't see a option in any menu

Edit -> Configure Options -> Display -> Show Standard Units

[Jkspeed]

That part throttle trick is pretty neat for when I'd rather not get yelled at by my friends neighbors.

[rob ms6gt]

I think the reason for the 2000 rpm start is to get the cats heated up quicker.

[mxlplx71]

Originally Posted by rob ms6gt I think the reason for the 2000 rpm start is to get the cats heated up quicker.

that makes sense, but I haz no cats

[rob ms6gt]

Me neether.

[ysaliens]

Any problems with the ECU map change compensation?

[Vansquish]

Originally Posted by ysaliens Any problems with the ECU map change compensation?

Six year thread necro. Nice. Not even sure what you're trying to ask.

[ysaliens]

I was wondering if those running the compensanted maps have had odd side-effects. 6 years is a long time but any issues would also come up by now.

The table still applies as far as I can tell.