Delco tuning for for dummys

[Dec_head]

Yeah it is odd because they have the sensor running off the left bank where the front 2 cylinders join on the pacemakers
It is a twin cat system will have to see where it will fit further down thanks
Also i have this odd problem if i put in a stock tune the car idles fine and goes back to idle straight away after a rev
If i use 12p v102 base tune when i i give it a rev it takes like 15 seconds to come back to idle
Isn't 12 p base based on a stock tune ?
just that i am going to start from scratch instead of loading other timing and fuel tables into 12p i wan't to try and figure it all out myself hoping that i might learn a thing or two.

[Holden202T]

is it a non heated o2, thats probably why its so far up the headers ....

$12P is based off BLCD i believe so if you want to compare apples to apples put a stock BLCD in and see if its the same as 12P or not.

[Dec_head]

BLCD is listed as v6 manual did you mean BLCF ?

[VL400]

Yep, 12P is based on a BLCF bin. Have you driven it yet or just had it idling? The IAC needs to learn the base steps, and if you have been playing around with throttle stop screw the base settings will be wrong until they are learned and saved in RAM. Swapping chips will clear the RAM and cause the learn process to start over. What stock chip are you using??

[Dec_head]

Yeah driven around if i use the stock hsv vs bmzl with knock and vats off it idles revs and goes back straight away to idle.
with the 12p it takes a while but gets there anywhere from 5 to 15 seconds .
WIll have a bit more of a play with it today and try the blcf stock tune and compare differences.

[VL400]

A data log from both may be a good starting point too, will give more info as to whats going on and what to adjust.

[Holden202T]

i'm putting my money on IAC steps

[Dec_head]

played around a fair bit with the tps adjustment it is much better don't know exactly what did it .
Now when i rev it the iac jumps up to something like 30 steps and then gradually within say 5 to ten seconds adjusts itself back to around 13 steps where it idles at 850rpm
Any idea what to adjust to stop the iac jumping to 30 when i rev it.
Where as before it would sort of lag from 1500rpm down and sometimes sit around 1100rpm for a bit before dropping
hoping this time it is right will let it cool down and see what happens.
I am thinking i might need bonnet vents and some sort of shield from engine heat to the air cleaner
when idling with the bonnet down the intake air temp goes above 120
Probably doesn't help having the hot air from the radiator pretty much blowing back straight into the air filter.

[VL400]

120deg intake temp is rather high

For the idle have a look at the table IAC - Throttle crack offset Vs RPM and also IAC - Transient IAC params - MAP Limiter Gain Factor combined with IAC - Transient IAC params - MAP Limiter Maximum Offset. The other option is IAC - Transient IAC params - Throttle Crack Decay Rate to adjust how quickly the steps are removed.

You can also adjust how quickly to return to closed loop idle with IAC - Closed loop params - Closed loop delay for opening throttle.


Idle control is a fairly complex subject, and is really easy to screw up!

[Dec_head]

Cool that worked a treat adjusted the decay rate from 3.75 to 5.75 made it a little quicker then i adjusted the throttle crack offset vs rpm like this
16.00
16.00
16.00
16.00
16.00
16.00
14.00
14.00
14.00
Seems to have done the trick