project_skyline

iTrader: (30)

Without looking at it. I had the same issue with my friends car, it doesn't like 17:1 or learner AFR's at light throttle. Simply put I changed them to around 14-15 and the car had no issues. Was still a little prevalent but not bad. I also blame it partially on the TB which is some ebay ford 4.6 TB i want to say.

What TB do you have?

Edit:
After looking at it first thing I can see is Idle FB is set too high, if the car is trying to idle itself and your driving in the FB zone it will cause it to buck like that. 2300 is way too high... I'd try at least under 1k.

If idle is setup and tuned right and you shoot for the right target AFR you shouldn't have as noticeable bucking. It should be more of a light studder at worst. When I first started out and hadn't even gotten to getting the fuel map figured out for low end it was so bad you couldn't drive it. Taking 10 minutes and the buck was down to a slight jerk going up a 18% grade hill.


Good luck!

arghx7

So have you really gotten in there and adjusted the acceleration fuel/throttle pump settings? This is often required on cammed cars. More overlap often needs more tip-in fuel due to dilution of the mixture. See section 6.7 of the AEMpro users guide. Here's how AEM describes the calculation:



I'd start by adjusting these values:



Incrementally lower the thresholds until tip-in correction is applied earlier. Then you may have to adjust the actual tip-in fuel maps. I'd start with the TPS related values first.

arghx7

Here's a little background info on how tip-in correction works, taken first from the Toyota technician EFI training guide and then from the DSM technical training manual. On the factory ECU there is synchronous tip-in fuel (sequential fired) and asynchronous (batch fired) tip-in fuel.



Synchronous tip-in is additional fuel added to the normal calculated fuel pulse with the normal firing order--it just "widens" the normal calculated synchronous pulse, increasing its duration. This is what your AEM throttle pump settings are doing. Asynchronous tip-in is additional fuel added to all injectors outside of the normal injector firing order:



I suspect the AEM EMS v1 is not capable of asynchronous tip-in correction. There doesn't seem to be any maps or options for it, but maybe the v2 unit can do it. A lack of asynchronous tip-in fuel capability is one of the reasons why standalones are known for these types of little stumbles. Here's an Evo factory asynchronous tip-in table: