Impreza trouble starting

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davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

At least let me PayPal you some beer tokens.

Attached is the config file.

In other news I tried starting with the throttle open a little, not different. Which is good news?
Attachments
config.zip
(157.73 KiB) Downloaded 343 times

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

Alright, here is your updated logging config.

The main change in the logging from your old firmware, is that there are many more items to log, and you can also specify that under a user configurable "high-load configuration" (say over 80% throttle and over 1 bar boost) different parameters are logged at different rates. Similarly you can configure different logging parameters to be logged upon a gearshift, after you lift off the throttle, etc.

I left your config as is, and just added some parameters to the "high load" logging config. You should notice no difference when logging.

Now you can run the 1.79.2 fw updater file. When starting SCal you will be prompted to flash a cal into the ECU. You can flash the updated cal, then open SCfg to load the updated logging config. When flashing the cal in SCal, pay attention to the status window in SCal in the bottom right area when the ECU reboots. It will give you any error messages that may occur due to a misconfigured parameter, though I'm sure there will be no problems.

You can then try starting the car, and see how it runs.

If the starting is still the same, as least we will have some more options to tweak now, and more items that can be logged to help us find the issue. If giving more throttle when starting makes no difference, we know that the engine is not starved of air during starting. It's just another datapoint to help us get you rolling.
Attachments
config 1.79.2.zip
(240.07 KiB) Downloaded 361 times

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

Forgot to add that should there be some unexpected issue, you can easily reflash your old firmware version and reload the old maps, just to put you at ease.

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

New firmware flashed and updated Cal loaded.

I also completely forgot to say that the car has 800cc injectors. Which I'm assuming will have some bearing on the fuel quantity for starting. :oops:

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

Cool. I'm guessing that the was no difference in the starting speed...

Let's try increasing the initial cranking pulse, and see what happens.

In SCal, under Starting -> Preliminary Fuel Injection 1, highlight the entire map by selecting the -30 cell, then pressing and holding Shift then press right arrow to select all the cells.

Press M, then M, then type 1.2 and press enter. This will increase the values by 20%.

Write the changes to the ECU by pressing D, then P.

Then test, and send along another log of the starting, please.

20% is a large change, you should immediately see a difference. You can try tweaking these values up and down slightly to fine tune afterwards.

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

Testing done, logs attached.

On the first start with a cold engine it fired up, like a normal engine. Took it a run to heat it up, started it again after a few minutes and it cranked, then idled slowly up to normal idle. Drove it back, let it sit while I drank a coffee, starting this time did its long cranking then started.

I did look at the logs in Sview and in one or two of the logs it cranks, runs, cranks and then keeps running.


zip of log files
https://drive.google.com/open?id=0B8FZe ... nRpaHlfaVE


Also drives normally with updated firmware and cal. :)

Slowie
Posts: 109
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie »

OK, looking at the logs, it seems like it is just a case of insufficient Preliminary injection. At ~20deg is starts up easily, at 85deg it takes a while, and at 95deg it coughs and drops back into cranking RPM (below 600) before picking up.

In Starting -> Preliminary Fuel Injection 1 I would select all cells from 40 to 140deg and multiply them by 1.2 again, as per previous post. If you want, you can increase the values from 60 to 140 degrees a touch more, to smooth out the "bump" at 60 deg. With the Preliminary Fuel map open, if you select "Options" in the top right, then "Auto Scaling", the bump is readily apparent.

At least the logs provide some more detail about the starting procedure now :)

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

Well I'd like to say it was fixed. But it's not. :(

Do you think it could be too much fuel and I should start again? Start with low numbers and see if it starts any better?

stevieturbo
Posts: 956
Joined: Sun Dec 07, 2008 2:04 pm

Re: Impreza trouble starting

Post by stevieturbo »

Always start low, otherwise you risk flooding/soaking the plugs which then causes poor starting, and you end up chasing your tail.

Really this sort of thing needs experienced eyes sitting there with the car whilst testing this. Trying to do it remotely can end up very frustrating for both parties.

davidmcluckie
Posts: 32
Joined: Mon Aug 14, 2017 8:27 pm

Re: Impreza trouble starting

Post by davidmcluckie »

Really this sort of thing needs experienced eyes sitting there with the car whilst testing this. Trying to do it remotely can end up very frustrating for both parties.
100% totally agree. I just haven't got anyone close by who can/will map/fiddle with it. So I'm grateful for any and all input.
I'm mostly bashing rocks together. :)

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