auto box not selecting gear

[tommo1965]

guys
My NS swb auto has developed a issue surrounding the selection of 5 gear...at around eighty K, if you accelerate hard it will bang into gear and hesitate on which gear it wants..either 4th or 5th...it fairly bangs into gear at this stage.

fluid level is ok and clean , but i do have a performance chip installed, would this affect the ECU in what gear it wants to select in a overtaking situation ?

Im gonna discount the chip and see if it sorts it out,,,,,

any ideas would be greatfull

[TheTaipan]

I guess it is under warranty so it is MM's problem mate.

[tommo1965]

it doesnt do it without the chip , so whats with that,,,could it be that its fueling it too much and the box has a wet fart and don't know what to do in that rev range/ speed combo.....with the chip in the loop the torque converter locks up way more than with out it ..still puzzled

i know the easy way out would be to dump the chip, but the car is way better to drive with it doing its thing

[Quadcam]

That sounds like the chip is modifying the throttle position signal and is causing the ECU to increase the line pressure in the auto. So the shifts will be harder and the ECU will delay shifts into 5th because it could be "seeing" more throttle position (and consequently more "load").

[tommo1965]

Any idea what to do , other than removing the chip,

[gaz1]

Might be worth talking to the chip supplier, it shouldn't be doing that so they ought to be responsible for resolving the problem.
Gaz

[tommo1965]

yes gaz I will

a bit more testing has given me some more info about this problem to share.

in stock form { no chip} the point that the gearbox is having a problem with the chip installed , is at eighty Kms, at this point { stock} i hit the gas and it kicks down into third..not forth as i was thinking.

it shifts to third then while keeping the right foot planted it then up-shifts to forth and then fifth.....so its at this kick down point that the box is having a problem selecting a gear with the chip installed ...

[tommo1965]

all sorted..i reset the ECU and all back to how it should be...with the fun chip installed

[Chip Tuning]

do you have the MAP sensor mod connected? If so, try removing it and reducing the tune to say Tune 3.

Let me know when you go.

Cheers

[tommo1965]

yes Rob..the map sensor is installed...after i reset the ecu..all well. im currently runing the same custom tune that Justin set up for me..i might change to tune 5 or 4 and see how i go...but at the moment all is well...and after a few days of no chip..i glad im back to runing with the chip in place...makes a load of difference down low

[Chip Tuning]

That's super.

Cheers