OK, got a problem that is not easy for me to explain.

When I lift of the throttle and hold the gas, just a fraction, the car gets jumpy, it starts to shake, it is ok if I lift of completely, or if I give some more throttle.

Is this something I can do anything with the injector settings?

My mate has also got the same problem, and we have tuned the cars separately.
And use different maps.

 

I assume you mean that the engine is jerky/not smooth; not the chassis/body.
How many rpms drop is this lift off the throttle when you then hold it?

 

I believe mine does the same around 2500-3500rpms, cruising rpms. Here is an example, when you let off to coast, but are giving it say 5% throttle just to keep from slowing so much the car starts jumping. According to the WB it is super rich like 10:1. I haven't logged it or tried to fix it though. Might just need to lean out whatever cell it is in, or could be slack in the drivetrain. I know my solid motor mounts seemed to help some. It also seems to get worse the lower rpms you run.

 

Then you have not AR tuned that part of the map (less load than cruising).

 

Thanks, and you are correct I haven't messed with that part of the map.

 

Ok, i did a 3 hour drive today, I am still braking in the engine, so I am not loading it much.
My cruise a/f is starting to get perfect, but it is like you say, and i have not done the lower cells yet.
I will bring my friend along tommorow and try to lean out the cells.

 

Example:

If at 3000 rpm in 5th and your PFC mainly runs in cell (P7,N8), and you tune for an AFR of 16.5 for good mileage; then (P8,N8) should be richer than 16.5.
(P8,N8) is the beginning of acceleration beyound cruising, but barely. You might tune it for 16AFR. Then (P9,N8) would be acceleration like 14.7 - 12.2.

Lower cells like (P1-P6,N8) can all be 16.5.

This works well for me except around 60mph were the secondary throttle starts to open but no fuel comes through the secondary injectors. I have to run richer around here, 15.5 - 16AFR.

 

Been leaning out the lower part of map today.
The car runs much better, did not have much time, but the runs i did was way better than the day before.

I am under 0,2 in the lowest grids, I see that is almost half of what you are running.

Is that normal?

 

I still get the problem.

And also when i go on the gass after shifting, it hesitates for a sec.
It make shifting a pain in the ***.
But if i go on the throttle very carefully it is not bad, but under normal driving it is bad.

 

I still am getting the problem.
I am trying to lean it out.
But I am afraid to go to low, but the lower i go the more it hesitates when i go throttle on.
If i go very carefull on the throttle i is ok, but with normal shifting it is a pain.
it also strugles when water temp is under 80C, but that can be adjustet with water temp correction i assume.

 

Download and ZIP your DAT and attached it along with a list of all engine mods that affect power production.