evil_eagle

iTrader: (4)

I've been working on the cold start issues with e85 AEM equipped evo's. I found some small areas that help a ton!!
My results are cold starts in 20 degree weather is on the 2nd try. Anything above 35 degrees out it fires right up the 1st try.

**VIDEO OF START UP ON E85!**
Some tips when starting your car. I've noticed if you time it just right when the fuel pump is done priming crank the car and it starts right up, it might rotate 2 times. If I wait too long after the fuel pump primes it turns over 5 or 6 times before fire.

You can hear the relay click off as soon as the fuel pump is done priming, once you hear the relay click off, fire the car immediately, I know it's stupid but it works. I wanna add that at different elevations these tables will have to be tweaked a bit, I'm at 2800 feet of elevation here in Idaho. At sea level you may have to add more to the "crank injector time table" Basically adding more fuel to the mix for lower elevations, and less fuel for you guys at higher elevations then myself

****Update****
currently my calibration is running 35 "microSec/bit" as most base maps use 75.

The "microSec/bit" can be found at "fuel/advance fuel/fuel trims" Up in the top right hand corner there will be a check box labeled "Options-fuel trims" And you will see " microSec/bit" in the box.

Now in order for these settings I posted above to work properly you will have to change the microSec/bit to 35.
to do this there is one important thing you must do.
You will wanna goto the main fuel map and click table view of the main fuel map. Right click and choose "injector duty cycle" once you have done that you will want to highlight the entire map and right click and copy. Now go back to the "microSec/bit" and type in 35. Now go back to the main fuel map and view it as duty cycle again, highlight the entire fuel map and right click and paste.

So here are some tables copied and pasted from my calibration for cold start on E85.

Car has 1000cc injectors
1 walbro 255 pump
stock fuel lines
stock FPR

1st off we are going to goto the "engine start" tab
click engine start
next it will bring up the basic engine start tables
now click "engine start/crank injector time table/table" and paste this into the table
115 126 136 145 150 151 151 151 151 151 151 151 151 151 151 0 0

Now in the top right hand corner of the engine start page you will see "crank adv" Set this to "27.30"

now onto the next step and that is the "warm up enrichment"
Click "engine start/warm up enrichment table/table" and paste this into the table.
19.53125 19.53125 19.53125 19.53125 19.53125 19.53125 19.53125 18.5546875 15.625 10.7421875 5.859375 0.9765625 0 0 0 0 0

Keep in mind the tables that I am pasting here are from left to right. since I can't make it one long line and it looks like it's in paragraphs.

Ok now we are done with that page, now onto the advance part of it.

Now click "engine start/advance start" and it brings up some more start up tables.

Lets start with the basics of this page. Up in the top right hand corner you will see a table box of different start settings
"crank inject all" checked
"crank minimum RPM" 50
"crank exit RPM" 375
"fuel pump prime" 1.55

K thats all done, now onto the tables, this is where most of the engine start problems are with AEM cars, allot of people ignore these tables and just use the base tables. The base tables in the base calibrations do not work so well with E85 and such. SO we are going to adjust this.

click "engine start/advance start/start extra Decay table/table" and paste this in
28.00390625 26.171875 24.6015625 22.76953125 20.9375 19.3671875 17.53515625 15.703125 14.1328125 12.30078125 10.46875 8.63671875 7.06640625 5.234375 3.40234375 1.83203125 0

Click "engine start/advance start/start extra vs temp table/table" and paste this in
104.4921875 96.6796875 88.8671875 80.078125 72.265625 64.453125 56.640625 47.8515625 40.0390625 32.2265625 24.4140625 15.625 7.8125 0 0 0 0

Click "engine start/advance start/Ign vs start time table/table" and paste this in
4.21875 3.1640625 2.109375 1.40625 0.703125 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

click "engine start/advance start/RPM offset vs start table/table" and paste this in
575 525 475 425 350 300 250 225 200 175 175 175 175 175 150 125 100 75 25 0 0 0 0 0 0 0 0 0 0 0 0 0 0


THIS ONE IS THE KEY TICKET!!
click "engine start/advance start/Initial Crank Pulse table/table" and paste this in
14080 14080 14080 14080 14080 14080 10240 0 0 0 0 0 0 0 0 0 0

Now typically the intial crank pulse table is the key thing when getting the car to fire in extremely cold conditions with E85. Just adjust the table in the low temp ranges, I've been adjusting it up till 86 degrees in the table. By adding more in the 30 degree range and lower temps I found the car starts much quicker.


Things you wanna adjust if these tables do not work for you guys, 1st the "crank injector time table" and the "Initial Crank Pulse Table"

Now one more thing to check and adjust if needed is the early sync table and such
to get to this goto "setup/sensors/cam crank sensor/advance cam crank sensor/advance pickups"
Now in the table in the top left hand corner labeled "Options Cam/Crank Setup"
Change the "Tooth time Min" to 500 mS
right next to the "options cam crank setup box" you will see another box that is labeled "options Sync Setup" Make sure the check box for "sync early" is checked


Now with these settings I have not once had to put my foot on the gas pedal at all.

Keep in mind these calibrations are for 1000cc injectors and E85. It has worked very well on my car so far and should work for most of you, the key things are timing the fuel pump prime just right, remember right after the relay clicks off for the fuel pump prime, turn the key. You get used to what the car likes after awhile. I've noticed in the morning it takes maybe 2 times to get it to fire off in 30 degree weather. If it doesn't fire off the 1st time I turn the ky back off and wait for the ecu to click off, then try again. For some reason this seems to help rather then just keep cranking on it for ever. Don't ask me why, it's just an AEM thing I guess


Good luck and if anyone needs some screen shots of what these tables should look like feel free to let me know and I will post up some screen shots.

This is going to be an ongoing thing so expect me to post more findings in my venture of the dreaded aem cold start issues.

evil_eagle

iTrader: (4)

A quick video of the cold start has been added to my original post.

MillDogg13

iTrader: (3)

Good info. I'm in San Diego and on cold mornings(probably low 50's) it fires, stumbles and quits, but fires up instantly on the second try. I may have to try this out with the aem.

evil_eagle

iTrader: (4)

After I posted this yesterday I realized there is one big thing I left out, that is "MicroSec/bit" This has a huge impact on the settings I posted above.

currently my calibration is running 35 "microSec/bit" as most base maps use 75.

The "microSec/bit" can be found at "fuel/advance fuel/fuel trims" Up in the top right hand corner there will be a check box labeled "Options-fuel trims" And you will see " microSec/bit" in the box.

Now in order for these settings I posted above to work properly you will have to change the microSec/bit to 35.
to do this there is one important thing you must do.
You will wanna goto the main fuel map and click table view of the main fuel map. Right click and choose "view raw" once you have done that you will want to highlight the entire map and right click and copy. Now go back to the "microSec/bit" and type in 35. Now go back to the main fuel map and view it as raw again, highlight the entire fuel map and right click and paste.

Aby@MIL.SPEC

iTrader: (161)

very nice.

does it start up just as well when warm?

evil_eagle

iTrader: (4)

Yes, consistent start ups no matter what the temp is, unless it drops below -0 then it might get tough to fire off, but it rarely gets that cold.

tony gibson

iTrader: (1)

Sawe it get to -4 in Mt. Home a couple of weeks ago!! Wonder how it wouldve cranked then...I'm shocked not many people have posted in here. This is exciting info for people in sub 40 degree climates that have AEMs.

evil_eagle

iTrader: (4)

Just a little update, it's been getting a bit colder here now and I made some more adjustments.

It seems the biggest impact is the "engine start/advance start/Initial Crank Pulse table/table" By adding almost double of what I posted above in the 20-30 degree area it now fires up just like it does in 40 degrees or warmer. Once you have all the other tables dialed in this is the only table you should be messing with for faster cold starts on E85. The other night it dropped down to 7 degrees outside and stayed around 17-20 degrees in my garage, by adjusting the table in the colder areas I was able to get it to fire on the 1st try after the car sitting for over 17 hours. So now I think I have mine dialed in to as far as 10 degree weather. Keep in mind I'm making 3-4 click adjustments on this table each morning. You don't wanna make HUGE adjustments, little at a time each morning. Once the car fires off for the 1st time it's going to fire off no matter what, so you have to wait till the next morning to make another adjustment. It takes allot of time but it's well worth it after a couple of weeks of tweaking on it. So bottom line is make just a few adjustments to this table each morning till the car fires on the 1st try.
I'm just happy I got this figured out and I don't have to worry about cranking the car forever to start on the EMS. Just takes time to iron things out!!

chuckbyu

iTrader: (3)

Nice work. I'm still running regular gas but i'll be switching to E-85 soon so this will be a big help. It was 6 degrees out on Monday morning when I went to work (not in the Evo). I always like to know the WHY behind changing things. Could you enlighten me on why changing the settings you did improved the start? Thanks.

boostGotMeLaid

iTrader: (6)

so this wont work with pump i assume?

how quick does the temps come up for people that a have built motors and wanna hit the road pretty quick

evil_eagle

iTrader: (4)

Of course the settings are calibrated for E85, but will work for gas just with less %'s to each tables. You will have to lessen the tables down a bit for gas but they should work. Like I said previously once you get the crank injector time table down for hot starts and somewhat cold starts then the engine start/advance start/Initial Crank Pulse table/table is the one that you wanna tweak on for extremely cold starts.
Engine start is engine start regardless of fuel, it just takes tweaking on each fuel you use.

I will be doing a cold start using strictly gasoline here soon, so I can post the calibrations for the cold start for gasoline only as well.

As far as how fast it warms up, with it idling at 1500rpm during warm up and slowly comes back down to 1000rpm when fully warm. It takes about 5-8 minutes to fully warm up. With E85 it just takes a tad longer to warm up since it's ethanol.

The Initial Crank Pulse table really controls how the injectors act during cranking, not so much how much fuel it's dumping but rather how they open/close vs your crank injector time table (witch is your base starting table IE how much fuel is being dumped), By upping this table it increases how fast the injectors operate, or so it seems. Either way, it seems to be working regardless. It doesn't seem to have the "flood" effect as the crank injector time table does. Again the Initial Crank Pulse table improves the over all starting of the car.

evil_eagle

iTrader: (4)

Also once I get through the winter with the adjustments the tables that have adjusted should work all year long regardless of weather/temps. I already have the cold start tables dialed in for warm weather, that wasn't so hard as most of you would agree, it's mostly in cold weather where the problems arrive. By only adjusting in the specific temps and leaving the adjustments in the warmer temps it should not effect spring/summer cold starts.

awdboosted

iTrader: (30)

Good write up.

evil_eagle

iTrader: (4)

^^thank you sir.

project_skyline

iTrader: (30)

So how would you modify the initial crank pulse table for pump gas versus e85, would it be even shorter because the difference in fuel characteristics?

Also why have the start decay table continue all the way down when you aren't adding fuel past 194F?

What does changing the microSec/bit actually do?