nsp software enrichment under sustained load

Is there a table or function in the nsp software that causes enrichment under sustaind load

This seems to be a issue at near wide open or wide open where it will hit the target lambda but once its been held there for 5 or more seconds it will start to get richer by 3 to 5 percent

Example foot to the floor at 6000 rpm within half a second iv got a stable lambda reading of .96 bang on the target itll hold there for for 4 to 5 seconds the the reading will start to drop down .92 over the next 10 to 15 seconds any ideas?

What vehicle is it, what modifications and tuning have been done, any other information?

I'm very far from any sort of "expert", but i can think of two possible reasons - there may be an enrichment protocol if the engine runs hot, or heat soak may be reducing the charge density which, if uncorrected for, will mean less oxygen available for the fuel, and if initial tuning was done on an inertia type dyno' that's even more likely as the engine may have been below normal operating temperature.

Its a crv with a k24a3 swaped in it na for now but the ecu is a haltech 1500 elite hence nsp software just started with a base from haltech for the k20 basically the same engine as far as cam controll ect just had to change injector size and setup dbw

So i have been working on the base fuel table and thats where im having the issue i mentioned above

What i am trying to figure out is if there is a compensation table or somthing that after a period of sustained fixed load at a fixed rpm that is causeing it to go rich as i said itll hold on the lambda target for about 5 seconds then start to go rich

Allso no i dont have o2 controll on to trim ill turn it on after im done tuning the base fuel table

And sorry gord no only half read your reply

Theres no corrections in the coolant temp past 65c as by then its warmed up enough ... allso temperature seems to stay prity stable at 80 85c once warmed up and eveythings stable regardless of how long its under load for

Air temp is a possibility but i wouldnt think so being n/a and the air temp stays stable in saying that tho the sensor is just before the throttle body not after but as i said n/a drawing fresh air constantly i wouldnt think the manifold would heat soak like that.

Allso if i lift and get back in to it it resets it . It will be on target again for 5 ish seconds then start to go rich

Cheers any ideas would be apreciated

Nick,

This could be caused by so many things, but have you logged it to see if your injector on time is getting longer at the same RPM/load or not?

If the fuel delivered is staying the same and the wideband reads richer, it's not from fuel mass change, it's from air mass change.

If fuel mass delivered is changing, you can log more monitors until you see which correction factor is increasing the on time.

I Had a brain wave mike may be on to it too

Im waching it happen live and yea iv pc logged and watched it over and over racking my brain

Rpm and load stays same injector duty cycle holds constant so i dont think the volume is changing

I think it maybe a fuel density thing being a dead head system thinking heat soak in the rail im gunna chuck a temp sesnsor in the rail and see if the math works out ill let yous know

Cheers

If you're referring to holding steady state at 6000 RPM under load, heat soak will reduce air mass and fuel mass will remain more consistent, so you'll end up rich.

IAT based fuel compensation helps account for this if the sensors is well located and reacts quickly enough to represent temperature well.