any aftermarket ecu /diy tuners - help with bucking
Discussion
run a old polo with aftermarket ecu (microsquirt) via tunerstudio
im fairly happy with the tune but get a nasty bucking /shunting on low tps , like when trying to tickle the pedal to stay at 30mph
tried a block of timing in that area from 12-30 deg , doesnt fix it
anyone able to have a look at some logs or give me some pointers please
im fairly happy with the tune but get a nasty bucking /shunting on low tps , like when trying to tickle the pedal to stay at 30mph
tried a block of timing in that area from 12-30 deg , doesnt fix it
anyone able to have a look at some logs or give me some pointers please
In my experience it is a major change in either timing or fuelling between two load/speed sites, I dont know what the grunlarity of these is on the micro squirt, but with the ECU I use I often improve granularity by having 200 or even 100rpm intervals between the lower speed/load sites to smooth the area as the interpolation can make assumptions which are often wrong.
Dave
Dave
similar experience - tends to be fuel or timing interpolation going wrong between load sites. Perhaps you might want to change your TPS load size for that particular row of cells to try and stop it bouncing between two cells.
While that is a low duty cycle, I would be looking at other issues that go hand in hand with injector limits like crap idle and difficulty starting (assuming you've got the enrichments reasonably tuned in).
If it's smoking AND it's hot, it's probably on fire... To me it sounds like interpolation too
While that is a low duty cycle, I would be looking at other issues that go hand in hand with injector limits like crap idle and difficulty starting (assuming you've got the enrichments reasonably tuned in).
If it's smoking AND it's hot, it's probably on fire... To me it sounds like interpolation too
ive played back the logs , pinpointed the time where it happened
admittedly my orig table wasnt the smoothest there , but ive spent a few hours punching in a whole block of xx deg so theres no flicking between numbers its all xx deg there , then try again with xxx degs and so on , doesnt fix it
admittedly my orig table wasnt the smoothest there , but ive spent a few hours punching in a whole block of xx deg so theres no flicking between numbers its all xx deg there , then try again with xxx degs and so on , doesnt fix it
What has helped me for similar problems in the past is running late and lean in the bottom corner of the map. My guess is by reducing manifold depression it's reducing the impact of cylinder-to-cylinder and cycle-to-cycle charge robbing. I'm no expert and can't say whether that's a good or bad approach, but it seemed to help.
GreenV8S said:
What has helped me for similar problems in the past is running late and lean in the bottom corner of the map. My guess is by reducing manifold depression it's reducing the impact of cylinder-to-cylinder and cycle-to-cycle charge robbing. I'm no expert and can't say whether that's a good or bad approach, but it seemed to help.
such as ? can you share what sort of numbers you have there please steveo3002 said:
such as ? can you share what sort of numbers you have there please
I haven't touched it for years and don't have access to that calibration at the moment so I can't say for sure, but I don't remember it being a huge change - probably just a few degrees of retard and about an AFR leaner. I made some small changes that seemed to help a little and kept going until it was good enough. This engine doesn't have an IACV so that part of the map also controls idle speed in my case.Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff