Impreza trouble starting

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Slowie
Posts: 101
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie » Fri Sep 08, 2017 9:08 am

davidmcluckie wrote: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?
Is it possible to give a bit more detail? Is it still starting OK when cold, consistently? If it is getting a bit too much fuel, adding throttle will speed up starting, so you can easily test that by dabbing it a bit whilst cranking.

You can certainly drop the numbers down to see what happens.

There seems to be two schools of thought when it comes to this type of starting fuel setup: One group likes to give a sizeable initial pulse, and the actual cranking fuel numbers are quite small, others seem to have a minimal initial pulse, and large numbers for cranking. Both ways seem to get the engine running.

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

Re: Impreza trouble starting

Post by davidmcluckie » Fri Sep 08, 2017 9:17 am

I think the problem is inconsistency. Which may mean it's not entirely a fueling issue.

For example, last week with an outside temp of about 15 degrees and the engine stone cold it started first turn. Yesterday, same outside temp, stone cold engine, crank and crank then spluttery start.

Then there is the hot start. Turn it off and back on it'll start first turn. Leave it 20 minutes and it'll crank and crank.

While it was hot I turned the fueling all the way down to 1 and up then to 10 and it started first turn on each flash.

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

Re: Impreza trouble starting

Post by davidmcluckie » Fri Sep 08, 2017 9:21 am


Slowie
Posts: 101
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie » Fri Sep 08, 2017 1:15 pm

Those logs actually DO show something inconsistent. According to your CAL, the engine should be in the CRANK stat anywhere between 100 and 600rpm, and above 600rpm in the RUN state (normal fuelling, etc).

But all the long stars (apart from 1), show the engine turning over at 150-200rpm, and in RUN mode, contrary to what the settings are. This could be an indicator of the issue. Maybe the crank/cam sensor picking up a phantom tooth (or missing a tooth)? This is really weird, we will probably have to call in the Syvecs support guys to the topic, as I am not sure of the exact background working of the ECU, and why it would incorrectly identify the engine runmode.

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

Re: Impreza trouble starting

Post by davidmcluckie » Fri Sep 08, 2017 2:26 pm

I don't see it as in run mode. I see the line showing CRANK then going up to RUN as it gets to 600rpm. But I may be interpreting it incorrectly.

The bit that gets me is this bit on the long cranks, where it starts with a low fueling (red circle) then halfway through the crank it doubles the fuel (blue circle). Is that the fuel multiplier?

Image

Slowie
Posts: 101
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie » Mon Sep 11, 2017 10:51 am

Only in the first log. In the other long startups, runmode says "Run", even though RPM is in the "Crank" range (below 600rpm)

Not sure how to interpret those starting fuel log values, my starting logs also show that doubling of final fuel when cranking.

Think it's best at this point to forward this thread to support@syvecs.co.uk (they don't monitor the forum 24/7), and see if they can shed any light on this.

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

Re: Impreza trouble starting

Post by davidmcluckie » Mon Sep 11, 2017 10:56 am

Slowie wrote:Only in the first log. In the other long startups, runmode says "Run", even though RPM is in the "Crank" range (below 600rpm)

Not sure how to interpret those starting fuel log values, my starting logs also show that doubling of final fuel when cranking.

Think it's best at this point to forward this thread to support@syvecs.co.uk (they don't monitor the forum 24/7), and see if they can shed any light on this.
Good plan. I've sent them an email.

Slowie
Posts: 101
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie » Fri Sep 15, 2017 7:23 am

Hi there

Have you had any update yet?

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

Re: Impreza trouble starting

Post by davidmcluckie » Fri Sep 15, 2017 12:22 pm

Sorry for the delay.

Reply - "Hi David,

That would be a fueling issue on startup, I would get in touch with your tuner to get this solved, should be a fairly easy fix"

Slowie
Posts: 101
Joined: Thu Jan 17, 2013 7:30 am

Re: Impreza trouble starting

Post by Slowie » Sun Sep 17, 2017 7:41 pm

Argh.

It is just a matter of raising and lowering that preliminary injection in steps, until the starting is crisp. Unfortunately you have to wait some minutes between starts, to see the effect.

Still not sure what is causing that intermittent bad start you still have at some temperatures.

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