Trans shift point adjustment

[hoopstar]

Well I finally have the VR 304 and 4l60e installed into my VK Calais and have been sorting through the teething problems..

One issue I am still having is the trans is up shifting at around 4,000 rpm for each gear.

I've spent some time reading a few posts from the forum which seem point to changing the TPS settings (due to the TB change) but so far haven't found anything for the $11p xdf (ie. scalar TPS - Throttle Gain %)

if youve changed throttle bodies you will need to recalibrate the range 0-100% via the scalar TPS - Throttle Gain %

I've gone through the $11P xdf and found the following settings but not seeing anything similar to 'Scalar TPS - Throttle Gain"

delco tps.jpg (175 KiB) Viewed 5138 times

Hoping someone might be able to point me in the right direction in terms of what I need to change to sort this out.

Specs for the car:
Stock comp VR 304 with fresh heads, crane valve gear and YT rockers.
Torque Power low rise, dual plane manifold and Holley Throttle Body.
Pacemaker extractors with single 2.5" system.
Rebuild 4l60e trans with corvette servo piston plus 2,200rpm converter
Stock VK BW diff with 3.08 gears

[Holden202T]

I guess the answer to how much you have to change them is going to vary depending how different the tps opening is with that TB compared to a stocker ....

the other question I have, is the speedo in a data log accurate to whats happening on the dash ?

looking at $11P there is a few tables you'll probably need to change if its TPS related, but I would have thought if your TPS was wrong it would mean that it is more closed that a stocker, so should be the opposite if that's the issue.

which makes me think the speedo pulse to the computer is getting a different reading than actual so its holding gears for longer ... see below tables, there is ones for all the different modes too, but start with normal mode (power button off and shifter in drive)

trans tps settings.jpg (217.93 KiB) Viewed 5128 times

get a log and post it up, might help for us to provide more info ....

[VL400]

You can check the speed is accurate, there are two scalars for the vehicle speed - one for the engine code and one for trans code. But for reasons that are discussed elsewhere (eg https://pcmhacking.net/forums/viewt ... vss#p65350) this is not really needed, your final drive ratio is probably different to stock but the speed sensor is on the back of the gearbox which will be the same as factory.

This also wont be the issue if its WOT shifting at 4000RPM, it will be that its not in kickdown mode due to the TPS. Kickdown mode looks at RPM and speed, both have to be above a set point with TPS also above a setpoint. T o fix this it will be the closed throttle gain in your picture. With engine off adjust so that WOT on the pedal shows 100% TPS in TunerPro.

Logs would show this too, if your unsure then as holden202t suggested post a log of it.

[hoopstar]

So here is a quick run of the car which demonstrates it holding the gear..

So something I didn't factor in is the vehicles tacho is still set as a 6 cylinder so showing higher than actual (hence the 4000rpm in my original post). That said, it's still holding 1st and 2nd until 2800 rpm with very light throttle.

One thing I noticed is the TPS % doesn't seem to be moving much but the TPS voltage is.

run1.xdl

(72.74 KiB) Downloaded 257 times

[Holden202T]

ok there are two DTCs logged, DTC 22 - Throttle Position Low & DTC 35 - IAC Motor Error .....

not sure how much that would be effecting anything, but certainly probably want to work on fixing them regardless....

its hard to say why its not changing, and its definitely changing a lot later than the data in the above tables is suggesting it should .... the question I have which you can't see from the logs is, when its saying 0% tps is that actually 0% pedal ..... or do you move the pedal before you start seeing the TPS move in tunerpro ?

turn the ignition on, engine off, record a data log, move the pedal from 0 -> 100% a few times and post that log please.

[hoopstar]

Well DTC 22 was the give away..

To quote the Holden V8 Diagnostic Trouble Code list: "The TP Sensor is one of the most important inputs used by the PCM for transient fueling and transmission control and for most of the PCM control outputs"

Checking the TPS at 0% the TPS voltage it was sitting at around 0.2 Volts. I read that this should be between 0.4 Volts and 0.7 Volts. The voltage would climb slightly with throttle input but the TPS percentage only started to increase once the TPS voltage reached around 0.5 Volts.

Since there wasn't any adjustment in the TPS, I slightly filed/slotted the mounting holes to allow me to add some 'pre-load' and get it reading around 0.5 Volts.

Took the car for a spin and the shifting problem was fixed - Now shifts like 'normal'..!!

MANY thanks for your help Holden202T..!! I really appreciate it.

I recorded another log and it's still throwing up DTC22 and DTC35 - do I need to somehow clear these before I record another log file???

[kojab]

Disconnect the battery for more than 15 seconds will clear the fault codes.

[hoopstar]

Disconnect the battery for more than 15 seconds will clear the fault codes.

Man I have so much to learn

Thanks Kojab.

[Holden202T]

good to hear! does the TPS show 100% now in the logs ?

[VL400]

Good work on the fix!

Can also clear fault code history using ALDL commands, some ADXs have them as a send command in Tunerpro. Useful to not reset everything the car or if you have closed loop LTFT and idle control learnt parameters you dont want lost.