hi first id like to say thanks in advance for any help iv'e had this problem on 2 cars and i cant get to the bottom of it.
iv'e spent countless hours googling and i cant find anything that has a solution.
the first car was an 855 t5 manual which ran great until i put on a rica 304 and what would happen is the car would jerk and buck when i let off the throttle at any speed and in any gear. I i put the standard ecu back in and it was fine. No matter how violently i lifted of it wouldn't do it. no with the rica in no matter how gently i lifted off it would do it.
i changed everything, all sensors, mounts, apart from fuel lines the whole fuel system and ignition system and nothing changed it.
i should add that the rica didn't cause jerking in anyone else's car and other maps including an MTE and a BSR both brought on this effect in mine, but no one else's.
now if i unplugged the tps it went in to a sort of limp mode but it didnt do it, needless to say a new one of them didnt cure it.
the only pattern i have noticed in both cars is that when you first start it up and its on choke as it were, it doesn't do it for maybe the first 1-2 mins of driving.
i ended up taking the rica out and selling the car because of this problem, as i was sick of spending silly amounts of money.
the second car is an 855 R which i bought as a auto, it didn't have this problem until it was converted to manual. it was still on a standard auto r ecu. from the minute i picked it up it was there. To say i was gutted is an under statment.
iv'e gone through the whole thing again and nothing has even come close to fixxing it.
iv'e put another rica or hlm on it and it still does it.
this cars has also had a full engine rebuild thanks to a piston ring.
the same stands with this one that while the engine is cold for the first couple of minutes it doesn't do it. it is less noticable in higher gears but is defanatly still there.
i thought well its running on the temp sender and then on the lambda after these few mins so ive changed the lambda and still no change.
can any one shed some light on this please