Hi guys
I have a chicken or the egg question!
When setting the idle with an Emerald do you adjust the throttle bidies first or the Emerald?
How do you get a base idle with out the Emerald trying to compensate?
What would be the highest idle speed I can go for be? (1000rpm is boring and just not lively enough)
By the way the idle speed control valve went in the bin a long lime ago.
Thanks for any replies,
Fluffy.
You need to set the throttle bodies first then set the emerald.
If you are aiming at an idle speed of 1000rpm, you want to set the base idle with a warm engine on the throttle bodies at about 100 - 200 rpm above that, so the emerald will then drag it down by adjusting the ignition timing.
Sean…
Here is the method I use, you can miss out the initial closing and opening of the throttle bodies if your engine is already running…
Setting up TBs for balanced running
Close the TBs completely and then adjust the balance mechanism so that both start to open at exactly the same time. open the throttle fully to make sure that all 4 plates are at the same angle when fully open to confirm they are in balance, it’s often easier to see discrepancies when the throttle is fully open.
When they are balanced by eye, open the throttle on the adjustment screw by a small amount. Align the throttle pot using the M3D software.
Start the engine and get to normal running temperature, if it wont start increase the throttle opening a little and re-align the throttle pot.
Then use the following procedure to set up the idle and corectly align the pot/map. It’s been developed over many many sets of TBs and works.
Note when setting the idle and balance do not under any circumstances play with the air bleeds to achieve idle, these must be in the fully closed position regardless of the type of linkage in use. These are for minor trimming between barrels when the balance between the two throttles on a single DTH TB is out and when the overall balance between the two TBs is as near as you can achieve using the balance mech. If you use the air bleeds to set the idle then the moment the throttle is opened the balance will got to hell in a hand basket and progression will be downright awful, you MUST balance the throttle plates and idle is the only place you can practically measure the airflow and achieve balance.
First…
Turn off idle control in the software!!!
Make sure the engine is hot
Make sure the idle advance is no more than 5 degrees,
Slacken the locking nut on the balance mech
Then…
i) make sure there is some slack in the cable.
ii) measure the airflow between TB 1 & 2 against TB 3 & 4.
iii) if 1 & 2 are low, increase by turning the balance grubscrew clockwise, if 1 & 2 are high reduce by turning counter clockwise. If they balanced lock up the adjustment grubscrew and ensure you have 1000RPM, if they are balanced and at 1000RPM go to viii)
iv) adjust the overall idle adjustment screw if idle falls or rises too much, set idle to 1000RPM
vi) if you have adjusted the overall idle adjustment screw then make sure you re-align the throttle pot in the software immediately.
vii) go to i)
viii) Let the engine idle and go to the live adjustments screen
Look at the lambda scale and adjust the fuelling until it shows two or three bars into the yellow, try trimming the fuel up and down two or three points and note the point at which the idle starts to fall in either direction, then go for the middle point which should give a clean and reasonable idle. If the idle starts to fall when you are adjusting the fuelling then you are going in the wrong direction, start adjusting in the opposite direction, The fuelling is right generally when the idle is at its fastest, if the Lambda scale doesnt appear or appears way off then it could be that your sensor is faulty. If the idle speeds up , adjust using the idle adjustment screw NOT the fuelling or timing, reset the throttle pot each time you adjust the idle screw. Recheck the balance.
When you have the idle stable and smooth at 1000RPM and the lambda reading consistently in the yellow by 2-3 bars then the idle is OK. Reset the throttle pot and set idle control on in the software with values of 25 degrees and an update rate of 10, then all should be well.
It might take a while to go round the cycle a few times, be patient, take your time, its worth the effort.
If you dont have a near perfect idle then you have not followed the above, I have never known it to fail.
Dave
Ok cool Sean but what stops the Emerald from trying to fight against the adjustments i’m making?
Say I want the Idle to be 1300rpm and the Emerald is set to idle at 1000rpm every time I try to adjust the throttle bodies won’t the Emerald try to force the revs back down to 1000rmp?
Hi Dave, great answer thanks. Don’t worry about the MOT side of things I just hate the 1000rpm idle. If this was an engine built for the track how high would you let it idle?
Ok cool Sean but what stops the Emerald from trying to fight against the adjustments i’m making?
Say I want the Idle to be 1300rpm and the Emerald is set to idle at 1000rpm every time I try to adjust the throttle bodies won’t the Emerald try to force the revs back down to 1000rmp?
And the answer would be turn off the idle control in the software… I think!
Firstly, turn off the idle control, then get the idle where you want it, then change the idle control to target whatever you want it to, it is completely configurable…
Dave