i have a problem that when im bout to stop, it would sometimes wanna die. idle would drop far enough that tach goes to "0" for a second then comes back up. If it doesnt come back up it just dies.
Now it doesnt do it all the time and it cant be a vacuum leak because most of the time the car idles fine.
Its just when driving and im slowing down to a red light or stop sign its acts up. any thoughts?

 

yea, first, check what speed your overrun settings are active over. this may be set too low and cause the injectors to not fire until the engine speed is too low. For an idle of about 800, my overrun speed is about 1200 and this seems to work well.

Also, set a low RPM bin in your VE map, like at about 200 rpm or so. make this a couple points higher than the next highest bin (so if at 50 kpa and 600 rpm, your VE is 55, make 50 kpa and 200 rpm about 58). This richer low bin will "catch" the engine if rpms drop too low and help keep it from stalling.

warm-up enrichment settings that are slightly off can cause this as the car is warming up as well.

 

If u mean "Over Run Fuel Cut" then it is off.

 

1) make sure u have play in you're throttle cable and it is not over tightened (this one little thing made me mess with my idle for weeks lol)
2) do as toplessFC3Sman says ve table bins one rpm range at minimum idle, one rpm range at idle(600,,800,,1000), and maybe one right after coming out of idle,,same with the ve (35,40,45,50,55).
3)Tune the idle when it is fully warmed up after driving 30mins (it may get a tad warmer after driving than just sitting and idling to warm up)
4) you may try playing with the ""idle advance settings"" add 10 when idle drops below minimum rpm and tps is closed (then add 2-3 # to the closed value) for example say the engine idles at 900 and u don't want it to go below 800 and the timing is at -5 to +5 setting example IA=10 TPS=48 RPM=800 CLT=150 sec=0!From what i under stand this setting was made more for a set timing advance at idle not really to correct a stall but it works good for stall issues also!

 

Normally the first thing I would check with that problem would be the brake booster/ brake booster check valve.
My FC used to do the same thing with the stock ECU because the TPS was not adjusted correctly. Of course MegaSquirt is a different beast than the stock ECU.

 

ill check that, nver had this prob with stock ecu

 

i had the same problem in mine. some say BACV, others say tps. what i did? i put more tention in my throtle cable. i made it all the way tight at throtle but it didnt change the idle. so i created tention in the line by using a zip tie to tie the cable tight against something close. it stopped all my idle problems. and it even seems like now i had more throtle responce and even more torque.
i wish i had pictures. but i removed that engine 2 months ago.
pm me for further instruction

 

i richened up the bins at 400 RPMS like state before and it has been working fine till now