Thread: Low throttle in gear bucking

Im not the best at searching but for the record I did search my a** off trying to find a solution to this prior. I apologize if my efforts were unsuccessful and the answer has already been covered before.

With that out of the way here is the situation.

These are the constants:

91 w/ sr20ve
msd 8969 on cams
nx9xtss clutch
ngk bkr5e plugs
ngk 8mm wires
new o2
new distributor
new cap and rotor
new air filter
calum basic
solid mounts
ssac 2 1/4"


The variables:

Switched intake pipe and vacuum lines. All seem solid, no leaks
Switched from DE Maf to N60 Maf. All wiring verified and re-verified.
Changed over bin for the ECU for the new MAF.


The problems:

Idle bounces a little bit. If i set the idle around 850 it will bounce up to 1100 every once and a while. If I set to 1000rpm idle it will barely move at all.

While in gear 1-5 if I let off of the throttle slowly it feels like im locking the brakes up and the car jerks worse than anything ive ever felt. The jerking of the car decreases the higher the gear I am in.

Here are what I think may be relevant images from the current bin on my ecu:

does it get better when it warms up? my car likes to be a whore when its not up to temp.. seems like others have similar issues, while some dont.

I actually only drove it after letting it idle for a long time to see if that was the case. Engine was up to temp and sat there for a while even before driving. Its actually a bin i got from one of your posts BTW that im using so you probably know it best haha. Its titled "alfredlesstiming-n60"

yea that bin should work fine, i've tested it an so has wojitek. i've had my issues long before i started tuning anything, way back when i had my calum basic with his ve bin.. which runs Fine in my gf's ve g20.. her engine doesnt do the dumb idle shit an wanting to die an bla bla.. kinda ticks me off in a way lol.. both engines have high port TB's even.. i really chalk it up to the IACV's they are evil i just fight it by slightly opening the TB with the little adjuster screw thing.. there are other ways to fight it, like by altering the cold start stuff. but i only messed with that a little an my laptops on the fritz so i cant really play with it much right now..

I tried using a bin I got from a calum post for my exact setup and my car wouldnt idle properly as in it would just fall on its face and stall out. So I compared it to yours and the injector K values were completely different so I did the math on it and yours was the right value thus I switched to your Bin and it cured that issue. I dont mind the idle bobble, its really a non issue to me. The main thing that worries me is the insane jerk i get when i ease off the throttle in gear. Its like engine brake x5 and it never did that before the maf and ecu change. Is there something in the ecu tune that can be adjusted for that? I posted up the maps and idle timing stuff because I thought maybe something in there could be tweaked.

what ecu did u run before?

Same ecu, different BIN. I was running the b13-sr20ve-ve inj-de maf bin from calum. With that bin the bucking only happened at really low speed in 1st gear with almost no throttle. I always had that pegged as just being what it is. 1st gear low speed low throttle. It wasnt nearly as bad with that Bin and setup though.


I just compared the DE maf bin vs the Alfredlesstiming bin with specifics on the Base Idle timing both in gear and neutral. The In Gear base idle timing is a 5 difference in all relevant temperature values and the Neutral is a 10 difference at the 110C value.

yea man ve's are tricky sometimes.. im still tryin to get my idle an crap 100% perfect.. when its warm its like 99.9% perfect but until then its a tad jerky an the rpms like to nose dive when i push the clutch in.. but atleast it doesnt die any more.. or idle at 1500 lol

make sure the ground of the maf is good.

Any chance those 2 timing map differences have an affect on the situation? Or for that matter any of the values in the Bin that control the 0-5% throttle in gear scenario?