Hello
We have been trying to figure out why our engine leans out at higer revs.
Logs, and msq can be found here.
http://www.dryg.se/~lasse/MS/080601/
Issue
Engine volvo b23, NA, twin throttle bodies 48mm
4 High impendance injectors @354cc/min
lamda LC-1
MS 2.0 V3
MS II code 2.885
Megatune 2.55p3
Engine Displacement 2314cc
Number of Cylinders 4
Number of Injectors 4
Number of Squirts 1
Injector Flow 354cc/min
Injector Staging simultanious
Fuel Type Gasoline
We first calculated our req_fuel to 11.4 and tried to map with that, but our VE then did not allow verry much, since many fileds ended up at more than 255 in the chart.
So we doubbled the req_fuel to get more room for mapping. Rec_fuel is now @ 23, but we still got tendency to lean out att high revs (255 in VE)
But Megatune does not allow us to have higher rec_fuel than 25, but we need 11.5 x 3 = 34,5 to get the VE corrected so we can map further.
Anyone with experience with alphaN mapping that could tell us where we went wrong?
AlphaN req_fuel issue
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
AlphaN req_fuel issue
Last edited by psbryt on Tue Jun 03, 2008 12:12 pm, edited 1 time in total.
Re: AlphaN req_fuel issue
The thing is that we calculated roughly that we haveLance wrote:psbryt,
I didn't look at your log or MSQ, but it sounds like you have hit the duty cycle limit and need larger injectors (and smaller req_fuel).
There is a pulse width limit in MegaSquirt, and I blelive it is 32 milliseconds for recent code. With a req_fuel of 34.5 and a VE of 255%, you are certainly over this. Again, the solution is larger injectors and a smaller req_fuel.
Lance.
200Nm tourqe
250Hp
The injectors should be large enough
Eaven if we alterd the req_fuel we did not se wider PW..the longest pulse we have seen is about 14
But we are now investigating if the fuel pump/filter is sufficient, so we are going to monitor the fuel pressure during load.