Last year, with the help of an experienced tuner via email, I got it to a point it was good enough and I just drove the car. I have covered it in a bit more detail in this thread on turbobricks: Īs detailed in the OP, this condition presented when I converted the car from ms2>microsquirt v3. sp=sharingīumping this up because this is still something I am fighting on my Volvo.
My latest log is too large to attach so taking my first shot at google docs (will fix if broken). Do I just keep working fuel into the table to try and smooth it out? I really feel like something is OFF, but don't know what it might be.
I've tried to do my due diligence with the mechanical stuff, something else I could check? Otherwise I am pretty green with the tune. At first I thought maybe it was some VE "sweet spot" with the new intake manifold, but now it's just a hassle! I have done the following mechanical checks: Fresh plugs, calibrated all the sensors, verified steady fuel pressure/tracks with boost, compression check is OK, no big glaring air leaks, plug wires have swapped.Īny help or thoughts on what might cause this kind of behavior is appreciated. Even with this big island of fuel I'm still getting lean swings around 3k, and the behavior seems generally inconsistent.Ĭonsistent throttle, consistent MAP, gradually rising RPM and the AFR is very inconsistent. You can pretty easily see in the VE table the direction we've been going. Going up a hill holding at 3k it will sit lean to the point of breaking up unless I "push through" it and get the AFR to drop back down. Mostly we have narrowed the lean peak, knocked it down a bit, and get rich condition around it. My tuner has been gradually increasing the fuel in that portion of the VE table but the behavior is very specific and strange. We've also been trying to get the +5,000rpm part of the map nailed down post fuel change. It will go from normal acceleration sharp to very lean then drop off a cliff. The problem: I have a very consistent lean spike around 2800-3000rpm and 90-100kPa. Looking back in older logs I can see some of the same behavior but it was less drastic and less noticeable in the car. Also I was having a major lean spike during normal acceleration. I had tuned around the fuel pressure issue unknowingly so I was pig rich under boost. Since then the tune has been more of an issue. Tracked it to a fuel pump which wouldn't push over 55psi and replaced it. The car was actually running fairly well a few months ago but I noticed high injector duty cycles under boost. Wasted spark, running 4 d514 coils with coils paired on IGN 1 and IGN 2įor edification, the following are the major changes since it ran great on ms2: Microsquirt swap, new wiring harness, ignition upgrade, swapped to high flow fuel pump -6 lines and a bigger fuel rail, big sheet metal intake manifold. 2.3l 8valve 4 turbo (~220 kPa max right now) I have been using the help of a very gracious Volvo guy who has a lot of MS experience during all of this. I decided to make some upgrades and in the process built a wiring harness and switched to a Microsquirt V3 and have been trying to get my tune back ever since. Last year I was running on ms2 v3, stock ignition and it was running great.
I have been running my 1979 Volvo 242 on megasquirt for almost two years.