The initial crank pulse table would be some what shorter on pump gas vs the E85, it's something you would have to keep adding to until the car fires up correctly.

The start decay table was adjusted at lower temps then it is a calculated line on upward towards 194F. This table doesn't seem to have that much of an impact, but everything helps.

MicroSec/bit controls the resolution of the fuel map, mostly the main fuel map but anything that has to do with any fuel adjustment the microsec/bit will have an effect on them as well. Max raw numbers the EMS will allow is 255. If your maxing out the raw number of your main fuel map then microsec/bit would be the section you will wanna adjust. The lower the number the more resolution you get thus allowing you to fine tune specific areas rather then having such a huge impact when making a small adjustment when the microsec/bit would be at say 75.

 

When you change to the microsec/bit number to something small it does make a smaller change but you can't run higher duty cycles.

Do I just need to find a number in between?

 

awesome stuff bookmarked for later

 

So i has read nearly everything possible about the AEM system, and found this description:

Crank Inject All
Enables a fuel PRIME pulse which is tunable by temperature on the "Initial Crank Pulse Table", adding a single pulse of fuel before "Stat Sync’d" is turned on and as soon as the engine starts cranking regardless of engine cycle.

Use: Priming a cold engine for starting. Typically the warmer the engine the less PRIME is needed.

So if i can understand it right : ONES you try to start engine it sprays some fuel in all pistons before "SYNC" comes on.
But again: What means the value ? How much fuel or how long it sprays or how long after cranking? What ?

This can help to rev-up your engine at cranking if your ECU hits the right moment for the injection, but how should it help for Syncing the signals. Another problem in my head: I was thinking the ECU will not spark or inject until she has Sync signal on. So if we will inject fuel but dont have spark.... ?


I am little confused on using AEM. Even stupid systems like Haltech does not need to be so hard tuned, dont need this "helps" on starting, dont need any correction tables for that or something other, for DWELL, etc....... Other ECUs are programed more user friendly. It looks like AEM has made ECU and we all need to do tuning work for them. Other systems are better developed, and you only need the tune Fuel, IGN, Boost etc.... but not things like "operationg parameters"

 

I wanted to update this thread a little bit, as going through my testing I notice a few things.
When adjusting cold start settings it seems that it is directly based off of your Idle A/F, idle parameters ect. So that is why every map is going to be unique in there own way as everyone tunes there idle differently then others.

For example. I had all my cold start settings setup perfectly and the car would fire off right away and idle perfectly without having to baby sit it.
I messed with some of my idle settings and the idle A/F one day and Low and behold the next morning when I went to fire the car off it would fire off like it always does but it would almost die right away, hmmmmm, fired it again and same thing, it would fire up then die. Thinking what the hell was different I went back to the only adjustments I made witch was the idle areas on the main fuel map in the 500rpm to 1500rpm range. I put them back to what they were before and fired the car off again, everything was back to the way they should be and the car idled fine after it fired off.

So in a nutshell, keep this in mind when making adjustments to your idle A/F and such. It WILL affect the cold start. I wish I could find an over all cold start setting to work for everyone, but it's just not going to happen as I mentioned before every map is going to be unique in there own little way.

 

Will def try this one I get my laptop back on windows.

 

thanks alot for this write up...I tried it and it worked really sweet....the car at first start in the morning starts after 3 secs and after that the car starts right up ...first turn and 1 sec start.......thanks alot for the good info...wish there were more people like you..And i hope i can find out something to help you guys out too.......

 

No problem man, glad it worked out for ya.

 

i have basically the exact same set up with the 255, rail, 1000's on e85 but im in denver so im twice your altitude.......so would that mean the values would decrease?

 

Crank injector time table would need to be reduced a little, maybe a few points but not by much. That should be the only table that you would need to adjust. The other tables should be very close.

 

This should totally be a sticky.

 

I've improved startup significantly with a lot of tweaking along with help from Evil__eagle.

But i have rev fluctuations at startup usually when its cold and its only for about 3-5 seconds.

Im guessing it has to do with ignition and fuel offset vs RPM. Or could it possibly be something else?

 

To get rid of that problem on 1st start goto "engine start/advance engine start/rpm offset vs start table"

And go ahead and flat line that table to 0. See if that helps, seems some cars like it at flat lined 0 and others like some correction in there.

 

I don't own an EVO but I'll like to thank you very much for posting, i've been searching for a solution for the cold start up problem for a while. As I read this, its like finding little gold nuggets!

A lot of the S2000 AEM EMS users/tuners are having trouble with cold starts, I'll definitely route them this way if you don't mind.

Thanks again, subscribing!

Paul

 

Not a problem man, glad I could help out some.