Setting up for idle with a (fairly) wild cam... Emerald
Discussion
Just up and running after a cam change (and head work) on a Rv8... cam is in the order of 300deg overlap 600thou lift whereas the replaced one wasn't 
so I need to try and reset things to get some sort of idle (I know it's going to be lumpy). Ports and inlet manifold have also been opened up somewhat so I'm thinking more advance and more fuel to start with...?
so I need to try and reset things to get some sort of idle (I know it's going to be lumpy). Ports and inlet manifold have also been opened up somewhat so I'm thinking more advance and more fuel to start with...?The Emerald doesn't use the IACV to stabilise idle speed as such, although it does have a table for opening vs. temperature for warmup, as well as a figure for startup. It uses igniton advance for idle control (assuming you want it to), so you would probably be best to get idle advance as close to 0 as you can and let it have a bit more air, rather than the other way round if you can - that way, the stabilisation will be much more effective. I'd imagine you'd want a pretty big fuel lift and advance kick in the maps as the revs drop below target too.
Top tip I got from karl was to see what it's actually giving by using the diagnostic page - this helps a lot during those "WTF is it doing" moments....
Another tip was to pop it in 2nd and drag it down with the clutch to confirm you've got the sites below idle right. Helps avoid wild swings around target.
HTH...but the experts are Emerald, so drop them a mail!
Top tip I got from karl was to see what it's actually giving by using the diagnostic page - this helps a lot during those "WTF is it doing" moments....
Another tip was to pop it in 2nd and drag it down with the clutch to confirm you've got the sites below idle right. Helps avoid wild swings around target.
HTH...but the experts are Emerald, so drop them a mail!
Hope you've got it sorted now. If you're still struggling to get a steady idle you might think about retarding the ignition (and opening the throttle to maintain revs). It'll idle hotter and use more fuel, but you'll get less manifold depression at idle and hence less exhaust gas recirculation. The higher air flow and lower EGR should improve air/fuel distribution and enable you to get a steadier idle.
Trick seems to be to add more air as suggested by Chris and Pete, which I've done via the IACV (quite big changes needed)... less advance (and possibly some to come off still), has got it behaving well enough to at least get running. As I understand the Emerald system, it uses coolant temp to position the IACV and then fine trims to the actual target idle speed for that temperature) by adding/reducing advance; success in this being dependent on having an appropriate range available with the given air stream. Not run it much so far but sounds lovely 
Hopefully drive it tomorrow 
Hopefully drive it tomorrow Ok, driven it a bit today and it's behaving fairly well; certainly better than expected. My open-loop best guess map has proved fairly stable around the AFR 12.5:1/13:1 mark, so I've slotted in an 'adaptive' version aiming for around 14s for normal driving. With the previous set up, it seemed to like even leaner running so I'm thinking that will be safe enough for low load steady cruising fot the time being.
It is a bit shunty at about 2k under light load (no surprises) but as the advance climbs steeply there, I'm thinking that moving the start of the climb to the next speed site might help.
Takes off like a scalded cat at about 3k and sounds awesome
It is a bit shunty at about 2k under light load (no surprises) but as the advance climbs steeply there, I'm thinking that moving the start of the climb to the next speed site might help.
Takes off like a scalded cat at about 3k and sounds awesome
Pupp said:
Trick seems to be to add more air as suggested by Chris and Pete, which I've done via the IACV (quite big changes needed)... less advance (and possibly some to come off still), has got it behaving well enough to at least get running. As I understand the Emerald system, it uses coolant temp to position the IACV and then fine trims to the actual target idle speed for that temperature) by adding/reducing advance; success in this being dependent on having an appropriate range available with the given air stream. Not run it much so far but sounds lovely Hopefully drive it tomorrow
Spot-on. Hopefully drive it tomorrow 350Matt said:
CorseChris said:
The Emerald doesn't use the IACV to stabilise idle speed as such,
Well it can support one as I had one on mine and I found it worked a treat, much better than relying on the ignition advance tweakery aloneWhen I put an M3DK on the Zetec in our Westy, I didn't fit an IACV initially and not surprisingly, cold starts and idle where less than perfect (I actually used the 'choke' cable that was part of the original setup on the GSXR that the TBs came from). Fine once warmed up a bit but in the end I just put one on and added the neccesary numbers in the IACV position/coolant temp table, plus an extra kick for startup. Sounds like you did the same and got the same results. I've also found the IACV tables very handy on my other car as this has A/C and the compressor does tend to pull it down a bit at times.
Shunting is often caused by it being a bit lean apparently. Have you got a wideband on it? If yes, try doing some logging/adaptive mapping in the awkward area. It takes a few miles but it does smooth it out. I did have trouble with this at one point when I was running batch fired as the MSPB was a bit big so it didn't really have the resolution to work with (injectors a bit OTT!) and it tended to hunt around each side of ideal at very light throttle. I changed to sequential and it now works a treat as it doubles the effective resolution.
It was Rover engine that got me into using Emerald ECUs. I had one of their first 16 bit units on a 4.2 motor. Long and tedious tale, but a certain 'expert' in the V8 world was unable to resolve the stalling problem the engine had on a chipped 14CUX so after a year of dicking about I put an Emerald on it. Transformed it.
Funny thing was....just before I sold the car, I finally figured out what the root of the problem was so put the Lucas system back on and kept the Emerald.
Funny thing was....just before I sold the car, I finally figured out what the root of the problem was so put the Lucas system back on and kept the Emerald.
Hi Gary, have you got it sorted yet? As has been said, the shunting is best solved by driving the car with the laptop on the passenger seat on the live readings page. Cruise around a quiet road and find the areas at which it shunts. Once you have one, hold the revs and add a bit of fuel using the adjustment keys until it goes away, and then quickly hit enter before you move off that cell. Did this with mine and managed to get rid of all of the shunting. Then when you stop, go to the injection page and you'll see all of the changes in red. Blend these numbers into the surrounding cells to get a nice smooth transition and then run that map on adaptive to fine tune it (using very small correction steps, so that it can only move things very gradually).
With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Trust me, there have been times in this build I would have believed something like that could have occurred...450Nick said:
Hi Gary, have you got it sorted yet? As has been said, the shunting is best solved by driving the car with the laptop on the passenger seat on the live readings page. Cruise around a quiet road and find the areas at which it shunts. Once you have one, hold the revs and add a bit of fuel using the adjustment keys until it goes away, and then quickly hit enter before you move off that cell. Did this with mine and managed to get rid of all of the shunting. Then when you stop, go to the injection page and you'll see all of the changes in red. Blend these numbers into the surrounding cells to get a nice smooth transition and then run that map on adaptive to fine tune it (using very small correction steps, so that it can only move things very gradually).
With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Hopefully will get chance to play with it this weekend Nick, so thanks for the input. All sounds good.With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Have got it to idle reliably enough but there is an 'iffy' patch up to about 2k that I am sure can be improved if not eliminated. I am happy to put up with a bit of intractibility but want to get it behaving as good as I can.
The cam is not an off the shelf grind but is a derivative of the H404 - think 234 on steroids (I know it's not blower friendly, looking forward, but I couldn't resist
)
Pupp said:
450Nick said:
Hi Gary, have you got it sorted yet? As has been said, the shunting is best solved by driving the car with the laptop on the passenger seat on the live readings page. Cruise around a quiet road and find the areas at which it shunts. Once you have one, hold the revs and add a bit of fuel using the adjustment keys until it goes away, and then quickly hit enter before you move off that cell. Did this with mine and managed to get rid of all of the shunting. Then when you stop, go to the injection page and you'll see all of the changes in red. Blend these numbers into the surrounding cells to get a nice smooth transition and then run that map on adaptive to fine tune it (using very small correction steps, so that it can only move things very gradually).
With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Hopefully will get chance to play with it this weekend Nick, so thanks for the input. All sounds good.With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Have got it to idle reliably enough but there is an 'iffy' patch up to about 2k that I am sure can be improved if not eliminated. I am happy to put up with a bit of intractibility but want to get it behaving as good as I can.
The cam is not an off the shelf grind but is a derivative of the H404 - think 234 on steroids (I know it's not blower friendly, looking forward, but I couldn't resist
)Will be running with Emerald also.
Poledriver said:
Pupp said:
450Nick said:
Hi Gary, have you got it sorted yet? As has been said, the shunting is best solved by driving the car with the laptop on the passenger seat on the live readings page. Cruise around a quiet road and find the areas at which it shunts. Once you have one, hold the revs and add a bit of fuel using the adjustment keys until it goes away, and then quickly hit enter before you move off that cell. Did this with mine and managed to get rid of all of the shunting. Then when you stop, go to the injection page and you'll see all of the changes in red. Blend these numbers into the surrounding cells to get a nice smooth transition and then run that map on adaptive to fine tune it (using very small correction steps, so that it can only move things very gradually).
With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Hopefully will get chance to play with it this weekend Nick, so thanks for the input. All sounds good.With regard to the idle, let me know if you still have problems. I developed a bit of a method to approaching it, starting with a fixed IACV value and no ignition control. Set the idle high (1.5-2k) and then gradually reduce it by tweeking the air, fuel and advance little by little until its down where you want it, then add the ignition control and target idle speed to smooth it out. Theres a bit more to it but I'm sure you've figured it out!
What cam is it? a 234?
Have got it to idle reliably enough but there is an 'iffy' patch up to about 2k that I am sure can be improved if not eliminated. I am happy to put up with a bit of intractibility but want to get it behaving as good as I can.
The cam is not an off the shelf grind but is a derivative of the H404 - think 234 on steroids (I know it's not blower friendly, looking forward, but I couldn't resist
)Will be running with Emerald also.
What blower you running?
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