Setting throttle pots and getting the adaptives right.
Discussion
Thanks to lots of kindly assistance from this forum I have now managed to get my cerb injecting on all 8 
Having managed that, I decided I'd just get the throttle pots spot on and fear that I have probably made a bit of a mess
My understanding is that, if the banks are balanced, then the adaptives should be the same, preferably around zero. Before I started this whole game I had equal adaptives, but around -20 and the throttle pots weren't far off. Unfortunately I'm not quite sure how to get back there.
SO far as I can see the only way to change the balance between the banks is to adjust the linkage between them for and then adjust the main tickover stop on bank 2 (offside?).
You can see below that I have the throttle pots balanced, however, the adaptives are miles off. I am also struggling to bring the tickover down now, even though the main tickover stop is wound fully in. If I balance the adaptives, then I haven't got enough adjustment on bank 2 to balance the throttle pots and also the butterflies on each bank are visibly out of balance.
What am I doing wrong?
Having managed that, I decided I'd just get the throttle pots spot on and fear that I have probably made a bit of a mess
My understanding is that, if the banks are balanced, then the adaptives should be the same, preferably around zero. Before I started this whole game I had equal adaptives, but around -20 and the throttle pots weren't far off. Unfortunately I'm not quite sure how to get back there.
SO far as I can see the only way to change the balance between the banks is to adjust the linkage between them for and then adjust the main tickover stop on bank 2 (offside?).
You can see below that I have the throttle pots balanced, however, the adaptives are miles off. I am also struggling to bring the tickover down now, even though the main tickover stop is wound fully in. If I balance the adaptives, then I haven't got enough adjustment on bank 2 to balance the throttle pots and also the butterflies on each bank are visibly out of balance.
What am I doing wrong?
It can take a bit of practice to get it right
Some tips that helped me
If you adjust a throttle pot you are just changing the amount of fuel being delivered to that bank
If you adjust the throttle linkage you are changing the amount of air flowing to the nearside bank and changing the fuel since the TPot is also moving
(The offside bank doesn't alter because its sat against the throttle stop)
If you adjust the idle screw you are changing the amount of air flowing to both banks and changing the fuel since the TPots are also moving
If the adaptives are positive then more air is flowing than is expected for the throttle pot position
and the converse for negative adaptives
Also have a read my post here on the method I use to set things up
I doubt its the definitive way to do it but it works for me
Some tips that helped me
If you adjust a throttle pot you are just changing the amount of fuel being delivered to that bank
If you adjust the throttle linkage you are changing the amount of air flowing to the nearside bank and changing the fuel since the TPot is also moving
(The offside bank doesn't alter because its sat against the throttle stop)
If you adjust the idle screw you are changing the amount of air flowing to both banks and changing the fuel since the TPots are also moving
If the adaptives are positive then more air is flowing than is expected for the throttle pot position
and the converse for negative adaptives
Also have a read my post here on the method I use to set things up
I doubt its the definitive way to do it but it works for me
Don't worry Jim - you're in good (bad?) company here - just had a go at this myself today having replaced Tpot 1 because I thought it was spiking - replacement also fluctuates though only +- 0.5 but still flutters whereas Tpot2 is rock steady under all conditions.
Anyway - thought I had it sussed set up wise and now the b
d won't start!
Any suggestions for a "get it going" set up from scratch?
Or is anyone around Southend area who has successfully done this and likes plenty of tea?!!
Anyway - thought I had it sussed set up wise and now the b
d won't start!Any suggestions for a "get it going" set up from scratch?
Or is anyone around Southend area who has successfully done this and likes plenty of tea?!!
Thanks Mike, I was already using your advice in the linked post actually, though it's particularly helpful to understand what each adjustment does.
Just a couple of things:
When you talk about the idle screw - I assume you mean the 10mm bolt which stops the return of the spindle attached to the throttle cable - or is there some other screw that I haven't found? At the moment mine is adjusted so that the butterflies are totally closed.
Also, if starting from scratch, what is the best order in which to sort things - visual check that butterflies are closed, then balance pots?
Also, what value should the pots have when the butterflies are totally closed?
Sorry for all the daft questions!
Just a couple of things:
When you talk about the idle screw - I assume you mean the 10mm bolt which stops the return of the spindle attached to the throttle cable - or is there some other screw that I haven't found? At the moment mine is adjusted so that the butterflies are totally closed.
Also, if starting from scratch, what is the best order in which to sort things - visual check that butterflies are closed, then balance pots?
Also, what value should the pots have when the butterflies are totally closed?
Sorry for all the daft questions!
Yes for idle screw I mean the throttle stop bolt
Starting from scratch I wind back the throttle stop and make sure all the butterflies are closing properly. Fully closed I set the tpots to 15%.
Then I open the throttle stop so they read 17%
(IIRC the 4.5 was closer to 19% at idle - but thats from a fair while ago watching Trackcar adjust a car when we were experimenting with mapping.
So you may want to try opening the throttle stop a bit more or starting with the fully closed reading higher than 15
Hopefully a 4.5 owner can confirm)
The car should start and run. If the idle is too fast/slow tweak the throttle stop.
I have a synchrometer (air mass meter) so I check the banks are flowing the same.
Then I start the tweaking process to get the adaptives right.
if it all goes pear shaped I reset the fully closed readings and begin again
The main thing is to decide what reading you think is wrong and then work out the steps to correct it
Make sure you use the AFR Status screen and remember there are only 5 values to worry about
Throttle1 (%) Speed (rpm) Throttle2 (%)
Adaptive 1 (%) Adaptive 2 (%)
Ignore the rest
I'd experiment by writing down what reading you think is wrong, what it should do (higher or lower) and write down what you are going to do to change it
Then make the change and record the result
I made a complete hash of it the first few tmes I tried because I didn't plan what I was doing and ended up making almost random changes
When I really started thinking about what was happening it was much easier to get it right.
hope that helps
Starting from scratch I wind back the throttle stop and make sure all the butterflies are closing properly. Fully closed I set the tpots to 15%.
Then I open the throttle stop so they read 17%
(IIRC the 4.5 was closer to 19% at idle - but thats from a fair while ago watching Trackcar adjust a car when we were experimenting with mapping.
So you may want to try opening the throttle stop a bit more or starting with the fully closed reading higher than 15
Hopefully a 4.5 owner can confirm)
The car should start and run. If the idle is too fast/slow tweak the throttle stop.
I have a synchrometer (air mass meter) so I check the banks are flowing the same.
Then I start the tweaking process to get the adaptives right.
if it all goes pear shaped I reset the fully closed readings and begin again
The main thing is to decide what reading you think is wrong and then work out the steps to correct it
Make sure you use the AFR Status screen and remember there are only 5 values to worry about
Throttle1 (%) Speed (rpm) Throttle2 (%)
Adaptive 1 (%) Adaptive 2 (%)
Ignore the rest
I'd experiment by writing down what reading you think is wrong, what it should do (higher or lower) and write down what you are going to do to change it
Then make the change and record the result
I made a complete hash of it the first few tmes I tried because I didn't plan what I was doing and ended up making almost random changes
When I really started thinking about what was happening it was much easier to get it right.
hope that helps
sorry for jumping in but i was thinking about tackling this one myself tomorrow, and this might seem like a stupid question but how do you adjust the tpot's, do you have to undo them and turn them or is there an adjuster screw? i have read alot of the related links and understand the theory of what needs to be done, its just the actual putting it to pratice.
thanks, will give it a go! i take it that you are using the download diagnostics from the dave hinns site, i just went on the site and downloaded the file, which saved to my downloads but do you know how a get it to be a useable program on my desktop, sorry i'm beter with a spanner than a computer.
thanks itiejim, that was easy and i didn't even get my hands covered in grease like normal!OK started again from scratch today - removed link bar - ensured both banks closed - set TP's to 15.2 - stuck link bar back on and adjusted so both tpots showed 15.2 proving linked but closed. Pulled throtte half open to ensure tpots matched - adjusted link to get closest match at half open with match closed. then brought throttle stop back up til pots read 16.8/17.3
Started car and bingo! Minor adjustments but adaptives between 0-3 on both sides with occasional fluctuation.
The car isn't overly happy when cold but My oh my!! when it's up to temp - that clatter cam kick at 4K has never felt so strong - it really is on song at the mo. And really barks when you stab the throttle from idle whereas before it was fluffing a bit.
Quite pleased with myself!
Started car and bingo! Minor adjustments but adaptives between 0-3 on both sides with occasional fluctuation.
The car isn't overly happy when cold but My oh my!! when it's up to temp - that clatter cam kick at 4K has never felt so strong - it really is on song at the mo. And really barks when you stab the throttle from idle whereas before it was fluffing a bit.
Quite pleased with myself!
Edited by smash on Thursday 21st May 20:04
smash said:
OK started again from scratch today - removed link bar - ensured both banks closed - set TP's to 15.2 - stuck link bar back on and adjusted so both tpots showed 15.2 proving linked but closed. Pulled throtte half open to ensure tpots matched - adjusted link to get closest match at half open with match closed. then brought throttle stop back up til pots read 16.8/17.3
Started car and bingo! Minor adjustments but adaptives between 0-3 on both sides with occasional fluctuation.
The car isn't overly happy when cold but My oh my!! when it's up to temp - that clatter cam kick at 4K has never felt so strong - it really is on song at the mo. And really barks when you stab the throttle from idle whereas before it was fluffing a bit.
Quite pleased with myself!
Fair play Started car and bingo! Minor adjustments but adaptives between 0-3 on both sides with occasional fluctuation.
The car isn't overly happy when cold but My oh my!! when it's up to temp - that clatter cam kick at 4K has never felt so strong - it really is on song at the mo. And really barks when you stab the throttle from idle whereas before it was fluffing a bit.
Quite pleased with myself!
Edited by smash on Thursday 21st May 20:04
[cheshire cat] Out again today - 21 gun salutes everywhere and going like a ding bat! Soooooo much more satisfying knowing I did it 
[/chesire cat]
One thing - the new tp from clever trevor still fluctuates a bit whereas tp 2 is rock solid. the Trevor clever one looks exactly the same as the one that came out but the rock solid one looks slightly different - is there only one part or are there alternatives? (e.g. some higher quality than others)
[/chesire cat]One thing - the new tp from clever trevor still fluctuates a bit whereas tp 2 is rock solid. the Trevor clever one looks exactly the same as the one that came out but the rock solid one looks slightly different - is there only one part or are there alternatives? (e.g. some higher quality than others)
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