Map Sensor Calibration & E85 Cold Start

Discussion and support for MoTeC's earlier generation ECUs

Map Sensor Calibration & E85 Cold Start

Postby Jayz-1 on Wed Aug 15, 2012 9:54 pm

I have asked this question before years ago but I still have the issue, but I do have more information on the subject now :)
I have a Delco 3 Bar map sensor connected to Aux Volt, (used for logging various items) as soon as I select "6" in the sensor setup I get a driver warn (stock CEL is wired into aux output 4)
Now I have worked out if I setup Aux output 4 to NOT show diagnostic errors the CEL goes away, however if it is on and I check the diagnostic errors screen on the laptop, no errors are there. Same thing used to happen with the AUX temp as well, until I changed it to a user defined table 0 - 1000 and no CEL for that input anymore.
So I can do the same with the AUX Volt output, but oddly enough it only works with some of them.
Options -5, -4, 4, 5, 6, 10 & 11 all have a CEL once selected, options -3, -2, -1, 1, 2, 3, all work without having the CEL coming on as a diagnostic error.
So not sure why it is doing this but I am open to suggestions to try?
My simple fix is to ask for the calibration settings for the Delco 3 Bar Map Sensor and ill just configure it as a 0 - 1000 user defined input.
What would be the settings I would use?
When I calculate 1000/5v = 200 *4.5v = 900 (this would be at 300kpa / 300A/D) and then 1000/5v = 200*0.5v = 100 (this would be 0kpa / 0 A/D) then interpolate, this gives me a value of 369 A/D at 100kpa, however the sensor is reading 328A/D at 100kpa, so I am not sure where I am going wrong with the calculation?

Second Issue:
Cold start with E85 requires a lot of fuel, I have maxed out the Post Start Enrichment and Cranking Enrichment but it still doesn’t start great when cold, if I increase the values at 100kpa & 0 rpm it starts better, however doesn’t start anywhere near as nice once up to temp.
Warm up enrich is set to water temp and once started idles at lambda 0.85 @ 10deg leaning out to lambda 1.00 by about 40deg so I don’t think warm up enrich needs changing.
Is there any way to get more adjustment out of it?
I don’t want to have to rig up a switch & relay that open circuits the air temp sensor while cranking and have the default value -20 with compensation of +100% or something which I will have to flip before starting the car but it’s all I can think of.

Open to suggestions :)

Thank you for your time.

Jason
ADR37/01 4G93T Motec.
Jayz-1
 
Posts: 10
Joined: Thu Jul 10, 2008 8:26 pm

Re: Map Sensor Calibration & E85 Cold Start

Postby Jayz-1 on Wed Aug 22, 2012 9:31 pm

Anyone?
In regards to the check engine light coming on could this have something to do with pull up resistors in the motec for various inputs? As its strange that it does it on some settings but not others.

Any input on a way to get more cranking enrichment?

Regards
Jason
ADR37/01 4G93T Motec.
Jayz-1
 
Posts: 10
Joined: Thu Jul 10, 2008 8:26 pm


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