Car refuses to start in cold conditions

Discussion and support for MoTeC's previous generation ECUs.

Car refuses to start in cold conditions

Postby scoobyman on Wed Oct 24, 2012 7:28 pm

Hi everyone,
I am having problems with starting my car, the colder it gets the harder it is to start.
Last week it was 5C outside and i had to crank it for 30 seconds to get it to start up.
This week it is -1C outside and i could barely start my car today, had to bring in a battery charger and crank it for a minute before it finally started. I'm afraid i wont be able to start it again if it gets any colder (and it easily gets to -20c here!)

I recently relocated to a colder climate and have not yet found anyone here, who is proficient enough with motec, to adjust the map for me.

Could someone please explain to me, whether i could do something about it myself (I have the can cable and the motec ecu manager installed on my laptop, but mainly use it for diagnostics), or is it something more complicated than that and requires attention of someone with experience?

If it is just a matter of adding a few values with lower temperatures to a table, could someone please point me in the right direction ?

I use Motec M800 gold

Thanks!
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Re: Car refuses to start in cold conditions

Postby 20B on Thu Oct 25, 2012 8:05 pm

I wish it was -1C where I lived :)
First up can you post up a copy of your ecu config for us to have a look at ?
Sounds like you may need to do a little work adjusting cold start fuel table and possibly cranking comp fuel table.
You can find these pretty easily , adjust - fuel - etc etc
You'd be surprised sometimes home much fuel you need to tip in there on cold start.
Mazda 1993 RX7
20B N/A engine
Motec M800,CDI, SDL, SLM, LTC, DHB
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Re: Car refuses to start in cold conditions

Postby scoobyman on Fri Oct 26, 2012 2:56 am

Thank you for your response, attaching a picture of my cranking compensation and my whole configuration file, let me know if you have any suggestions, thanks!
Attachments
Impreza B4-95 ron fuel.e35
(72 KiB) Downloaded 989 times
fuel comp.jpg
fuel comp.jpg (31.02 KiB) Viewed 22254 times
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Re: Car refuses to start in cold conditions

Postby Arve Flaat on Fri Oct 26, 2012 5:45 am

Hi

This is your cranking comp table.
How is your engine temp table?

AF
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Re: Car refuses to start in cold conditions

Postby ElectronSpeed on Sat Oct 27, 2012 3:29 am

I agree with the direction that Arve was going. I would have expected the engine temp comp on the base table to be twice as big. However, it depends on what the engine is doing when do try to start it. It doesn't fire? It doesn't stay running? . . .

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Re: Car refuses to start in cold conditions

Postby scoobyman on Sat Oct 27, 2012 8:17 pm

Here is the engine temp table.

It's both really, it fails to fire up for the first minute, then once it fires up it stalls and then i have to fire it up again and hold the gas pedal in for a second or two to let it come alive, then it's fine.
Attachments
eng temp.jpg
eng temp.jpg (75 KiB) Viewed 22156 times
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Re: Car refuses to start in cold conditions

Postby stevieturbo on Sat Oct 27, 2012 9:28 pm

I'd easily be doubling or tripling those numbers in the coolant enrichment table

Also fill in some values for colder temps too in case you see them.
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Re: Car refuses to start in cold conditions

Postby scoobyman on Sun Oct 28, 2012 11:14 pm

stevieturbo wrote:I'd easily be doubling or tripling those numbers in the coolant enrichment table

Also fill in some values for colder temps too in case you see them.


Thank you, will try that.

Should i also adjust the Fuel cranking compensation values and add some more for lower temperatures?
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Re: Car refuses to start in cold conditions

Postby Arve Flaat on Mon Oct 29, 2012 6:04 am

Hi

I think you should enter Motec help (F1) values in all tables.

Engine Temp is the main value, the others are just additional fuel at cranking.
I use a rising main table on 0 - 500 and 1000 rpm. Then I can use the TP too find out if I need more or less fuel at cranking.

PS: Make the warm start perfect before you adjust cold start. All cold start parameters are additional fuel too warm start.

AF
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Re: Car refuses to start in cold conditions

Postby Dragon on Tue Oct 30, 2012 12:52 pm

Yes, I agree that the Engine Temp should be attended to first and values should be at least doubled.
I usually use TP for Y axis.
Use a wideband lambda sensor to look at AFR changes during warming up.
Fuel AT Comp table is not really set. You might want to have a look there as well.
IGN ET Comp can also used to help cold start and running.
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