Ok, so I've tride going with TPS based, MAP based and RPM based in both TPS and MAP. Going from no throttle coast to any throttle, either a gentle squeese or a good hard prod, it hesitates. When allready on throttle, maybe 5% or so such as in a cruise situation as throttle is added it leans our for a split second before going to its normal accel slightly rich condition. I've probably spent at least an hour a day for the past 3 weeks trying hundreds of different tunes only to come out with the same results. Its not really a problem driving around town, but getting agressive in the canyons it is. Going from trail braking back to on-throttle, even just breathing on the gas, it hesitates then comes back rather harshly. Mid-corner harsh weight transfer isint exactly a good thing...

 

What parameters do you have for TPS based fuelling on MS?

I had the same issue before, and when i had my car tuned the tuner got rid of 99% of it...
I can post my aem throttle maps tonight if the parameters would be the same.

What TPS are you using?

 

Its a 95 so I have the variable TPS. Timer is set to seconds, decay enrichment. value at end of accel 0.2. In the Wizard TPS isint tuned in this perticular version of my attempts.

*edit:update*
I can get it tuned right to where it wont stumble above the initial ~5% throttle. however, regardless of RPM crossing from no throttle to anything causes the stumble. If Im allready cruising with say 10% then no matter what I do it WONT stumble. its just that first little bit of throttle that either I'm thinking its not being compensated for or its giving out the wrong signals. Pulse width through that small window is VERY erratic... Im frustrated to say the least.

 

Too early in the AM for me to be thinking clearly, but what you describe sounds similar to the problem I ran into when my Over Run settings were off. (More Settings/Over Run Fuel Cut) Turn yours off, if it fixes the problem, turn it back on & work the settings.
I'll be going back to bed now.

 

Are your enrichments kicking in early enough?

What are your TPSdot/MAPdot thresholds set at? Where is the lowest dot on your enrichment curve(either volts/sec. or KPA/sec.)?

 

Sadly still having problems. Overrun is off, TPSdot, 0.195 threshold. starting at 0.0 v/sec 0.3 PWms, next 1.0v/s 7.5pw, 3.9v/s 11.4 pw, 15.1 v/s 14.0 pw, accel time is 0.3. Accel timer is in seconds, non-decay, and Im not boosting so the turning off of enrichments isint touched. Still stumbles going from no throttle to something, worse when going from no throttle to full quickly as in a shift when running hard or throttle blip in a heel-toe downshift.

 

Wow, I'm surprised with settings that low that it doesn't remedy the problem. Have you tried more than .3 ms? You could also try slightly richening the first row of ve cells above and to the right of your idle cells and see if that helps. Post up a log and your msq.

 

make sure RPMdot is disabled...post the msq.

 

Well, I just solved it... Its gone completly. Upgraded to 11d hires firmware. Only I have a different problem now... Going to search elsewhere or post in proper thread if I find something.

 

Would your new problem by any chance be either (a) intermittent idle droop/misfire on tickover or (b) Major midrange over-fueling?

Vince.

 

What firmware were you running before?

 

Dead thread revival! Well I had the issue fixed for a while, but it seems it wont stay put. Without touching ANYTHING the most life i get out of a tune seems to be about a week and a half, then the tune seems to wander... I dont know whats going on here but it seems like MS is either compensating or not compensating for something. Seems weather related but more general than day/night... The accel will be fine for a while then they go to **** again and I have to re-tune.

 

i get that too - ECU just seems to be really unstable.
sometimes it will behave perfectly, idle's rock steady and no hint of lean spike on accel tip-in.
other times, MAP and RPM oscillate at idle even with a steady idle DC, and car hesitates slightly on accel tip-in due to initial lean spike. again, normally takes about 4-5 days to start going randomly bad after i've got it running nicely, without touching anything, not even plugging the laptop for datalogging.

and i have no idea why - ambient conditions are the same. i can even turn the car off and back on 10 seconds later and it behaves different. sometimes makes me want to go back to stock (tho when it's working it's goooood!!)

 

I bet if you DID log, you'd find the ECU doing something you weren't compensating for...

 

What should I be looking for exactly? Im not sure that baro compensation is functioning properly but Im not sure where it is exactly I need to look to check that it is. I will run some logs today and see if I can somehow translate what gets chisled into my old stone notebook to modern day computers. Its like trying to translate hiroglyphs to english without the rosetta stone...

 

what are your baro limits? if set improperly that cause cause all sorts of havok.

baro should have a range of ~90-110kPa...it you have the window above that I could see an issue.

 

actually the records for highest and lowest pressure measured on earth would suggest 87 to 108.5 as the best limits.

 

well when it does it enough to really **** me off then i log it, and normally when i burn a new VE table onto the ECU even if the cells in the idle region, it sometimes sorts itself out for another couple days. certainly, idle DC, Gair and all of that stuff (GammaE) can be completely constant and the RPM / MAP will just bounce at idle (i set my idle via the screw so that the engine speed at the closed idle DC is slightly above my warm RPM setting so that in normal conditions, idle DC doesn't need to kick in under a steady idle).

However, before I only had one cell for my idle area and now i've got 4 cells on the VE table and spark map (MS1 so i can't dedicate too mmuch resolution to that area) so am gonna have a play and hopefully i can start to get it a bit more stable - i don't think the AFR changing with the MAP/RPM was a massive problem (bouncing went from 14.5 - 15.5) but the spark timing bouncing a few degrees probably wasn't good.

just really frustrating that the problem comes and disappears seemingly randomly

 

HIGHEST ambient Kpa Ive seen in my driveway = 86
lowest was 82
engine off Ambient pressure check.

Allright well, bit of a delay in running megasquirt and getting logs. Namely a random deer, and a curb, and a bent lower control arm.