Thread: Cold Start Stalling. how many of you out there have it?

hmm that sound like the problem, rich untill warm then ideal idle and air fuel ratios

altho i see normal opp temps pretty quickly about 15 mins in 56* weather

see i am kinda smart sometimes

Cold start and Idle needs to all be setup man. It isn't that hard, but it is really hard to explain in a forum post. You should be reading the AEM EMS guides, not asking a bunch of people that don't have ems and don't ever deal with this stuff.

Everything these people have said may help on a stock or JWT ecu, but won't get you anywhere on the ems.

You need to first increase your start extra and start extra decay tables, increase both in the cold temp areas, keep the graph linear (straight line). You also need to configure the idle % table. Once you have all that, go in and setup your DFCO (decel fuel correction tables).

Brent

well i actually already setup all of the tables when i tuned it (i tuned it last winter so i setup the tables when it was actually cold and didnt have the problems then)

only real reason i asked was becuase i was thinking that my coolant temp sensor might be going, i have done some reading and it seems like it could be a bad coolant temp switch

the hard start, wont idle without being throttle bliped, dies out without some pedal work,even with the aac screw all in the car wont idle down from 1500

my base idle is screwed up. the car hardly idles when it's cold. then when it's warm, it idles but when im driving and push the clutch in, the car dies. so i'm going outside to adjust the iacv right now. gotta get the car ready for oxnard in 12 hours.

very good grasshopper. you've learned quickly. You're right though, not many folks on here with AEM EMS to understand which parameters you have to deal with on cold starts. I've had my fair share of headaches back in 2001 when i first got it for the teg then my customers' s2k as well.

You need to get the car to operating temps, verify timing and tps, then set base idle. Once the base idle is set when warm, the ecu (when using JWT or STOCK) will take over based on reading from the coolant temp sensor and adjust idle.

BRent

No sense messing with the idle screws man, it won't help you. Just screw it all the way in and back it out two turns. THen setup the idle % table in the idle section. YOu do that by setting the whole base idle table to the same RPM and adjust that RPM point till the idle learned value is around 0. Then, increase whole base idle rpm table to the next RPM point and do it all over. ONce you do every RPM point the whole idle % table will be set.

THen, you use the start extra and start extra decay tables to adjust cold start and idle and you also need to setup the warm up enrichment table. Those will keep the car idling when cold and it won't stall after start.

Brent

timing is set. tps is set. base idle is not. the car had much smaller throttle body on it before and it was tuned on that one. now it has the o2 induction manifold on it. kojima tried to set it tonight but the car still wants to fight itself. because the base idle is off, the will rev to about 1100. then because it thinks the engine is under load but sees the tps closed, it cuts fuel. so basically i just get a surge from 1100 to 800 back and forth and back and forth. car is driving me crazy!

thank you for that though brent, i'm going outside to play with the aicv soon to see if that helps at all.