2.5 to 3.0 problems

[RobseyMV6]

Just changed a 2.5 to 3.0 both auto, change to AR35 box with the swap now won't change up to top gear and when take foot off gas it changes down straight down the gears, never has a omega done that before to me.

I know you would say check codes but for some reason that bulb will not light up at all and have changed bulb to see if that would light that up.

Another problem the car now won't rev past 3.5k without just dieing 
Changed engine ecu to 3.0 one no change.

Check ATF 3 times now and is spot on.

Anyone had this problem??

[Brikhead]

Maybe the electronic control units are different between the two models?

Gearbox e.c.u. lives behind the dash, inbetween the clocks and fusebox area.
looks like this....

I should have one from a 3.0 auto knocking around in the shed, if needed I could dig it out and check the numbers against the one above.

[RobseyMV6]

Got the box from my mate and have asked him to find this out for me as i'm thinking the same as you, thank you!

[Brikhead]

Good luck with it.
Have you kept the 2.5 diff?

[RobseyMV6]

Good luck with it.
Have you kept the 2.5 diff?

Still in car but will be changing soon to the 3.0 diff 

[RobseyMV6]

Same problems after have now codeed car and have 21 and 91

[feeutfo]

21   Throttle Position Sensor (TPS) Voltage High... Might explane rpm issue?
91   O2 Sensor 2 Circuit Voltage High



Any communication with auto box ecu?

[Marks DTM Calib]

Number one rule of an engine change is to keep the original sensors and ecu etc.

This is because there are some electronics  differences through the manufacturing years, a classic one being that the throttle pot was changed (which is one of the things you are seeing) meaning the ecu sees it as open when its closed!

[RobseyMV6]

Shell replace bits back and see soon.

Thanks

[Kevin Wood]

Yep, this has been seen before. IIRC, throttle position sensor and/or wiring has swapped ends between open and closed, can't remember which, though.

Worth trying the throttle body off the 2.5. Failing that, the 3.0 engine loom.

[RobseyMV6]

Yep, this has been seen before. IIRC, throttle position sensor and/or wiring has swapped ends between open and closed, can't remember which, though.

Worth trying the throttle body off the 2.5. Failing that, the 3.0 engine loom.

You are the man along with Serke Kevin 2.5 throttle body sorted problems but will in the end change loom as feel something just not 100 percent to 3.0 engine but all good for now.

Thanks all 

[Kevin Wood]

You are the man along with Serke Kevin 2.5 throttle body sorted problems but will in the end change loom as feel something just not 100 percent to 3.0 engine but all good for now.

Thanks all 

Good to hear it

At the end of the day, the loom has to stay with the throttle body that it was originally with. Wires swapped over on the short plenum throttle position sensor, and then swapped back in the loom, IYSWIM?

It's not impossible that there's something else more subtle that's still wrong, of course.

[feeutfo]

So as Mark says, keep ALL the electric components with the car. Noted.

[RobseyMV6]

Going to replace loom tomorrow with 3.0 as have one now and change throttle body's over as not 100 % with the 2.5 one's but running ok.