rough running

cmd273 · Post by **cmd273** » Tue Jun 06, 2006 7:34 pm

I have an vw 16v turbo running megasquirt, its running pretty well I think, however, my idle is really rough, and the acceleration seems jerky. Would any experienced users be willing to look at my datalogs and give me some pointers?

Please lemme know thanks.

cmd273 · Post by **cmd273** » Wed Jun 07, 2006 3:40 pm

Would using autotune be a good step in cleaning it up, I have been reading up on it, I think it would work for my aplication. Its turbo charged, but I do have a wide band.

qadir03 · Post by **qadir03** » Thu Jun 08, 2006 1:52 am

Are you running ignition control? Wideband? What Kpa are you idling at. My first suggestion would be is to make sure you are not hunting around on various table points. Adjust your points so it corresponds to your idle rpm and load(kpa). Ensure that all the VE values around that part of the table are the same. Then increase or decrease your map according to what the engine wants.

mops · Post by **mops** » Thu Jun 08, 2006 12:41 pm

timing and amount of idle air is crucial for steady idle.

generally idle timing should be anywhere form 5 to 20 degrees BTDC, try with 10 or 12 for a start.

idle air is crucial... too much will cause rolling idle - idle going up and down all the time.... called rollind because if you look at yout grrrn point in the fuel map it will be going around circular motion

too little idle air will make engine weak to the point of not being able to run without throttle.

about making your ve table smooth - what you actually want is a stable pulsewidth +- 0.2ms is still considered ok, but if it is -+ 0.5 it will be feelable....

let me know how you went.