Direct injection pressure drop

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NenadNR
Posts: 8
Joined: Mon Oct 29, 2018 8:30 pm

Direct injection pressure drop

Post by NenadNR » Tue Mar 26, 2019 6:40 pm

On 1.2 bar boost rail pressure is stable on full throttle. On 1.4 bar boost it goes down then injector duty cycle goes to 100% and then rail pressure goes back to target. I can not find why so help needed.

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stevieturbo
Posts: 834
Joined: Sun Dec 07, 2008 2:04 pm

Re: Direct injection pressure drop

Post by stevieturbo » Tue Mar 26, 2019 11:13 pm

There's nothing on that graph to get any help.

Proper log is needed, vehicle details, and ensure you're logging what all the fuel controls are actually doing relating to pump/pressure etc. Both high and low pressure.

NenadNR
Posts: 8
Joined: Mon Oct 29, 2018 8:30 pm

Re: Direct injection pressure drop

Post by NenadNR » Wed Mar 27, 2019 11:10 am

Attached you may find log I have. I will make new log with all controls logged. I did not logged all for hi pressure.
Vehicle is RML Cruze WTCC from 2011 season. Engine is Swindon BTCC. ECU is custom Life Racing with standard firmware.

Also I have a question about knock sensor event detection level. Signal from knock sensor is noisy and with event detection level 50% above average signal there is ignition retard even on lower load and ignition angle. Is it safe that I put event detection level higher and how much?

Thank you.
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stevieturbo
Posts: 834
Joined: Sun Dec 07, 2008 2:04 pm

Re: Direct injection pressure drop

Post by stevieturbo » Wed Mar 27, 2019 5:24 pm

You seem to be loading up a pretty cold engine there ?

And I dont really see any fuel controls that might give any indication of whether there is a problem as such. FP1 I can only presume is the low pressure side and is remaining pretty static, which would suggest it is ok.

AFR's are fairly stable and close to target throughout though.

It may just simply be it needs finer tuned, or there may be some high pressure issues.

As for knock, that's going to be up to you to determine what is safe for you, and whether any "knock" detected is real or not.

NenadNR
Posts: 8
Joined: Mon Oct 29, 2018 8:30 pm

Re: Direct injection pressure drop

Post by NenadNR » Wed Mar 27, 2019 8:36 pm

I told the driver to warm it up properly next time. Problem is that when we start dyno fans all temperatures go down very quickly on light load.

FP1 is low fuel pressure.

We will try again in two days. I will play with hi pressure fuel pump controls and log everything. Problem is that I can't find any difference between 1.2 bar MAP when everything is fine and 1.4 bar MAP where problem starts. There is no significant rise in fuel flow from 1.2 to 1.4 bar MAP and hi pressure target is same. Maybe there somewhere is limit for current hi pressure fuel pump control settings. I am not sure about some settings there. Control valve hold angle is 45 degrees on all RPM. Should I try to put higher values on higher RPM? Also Base Load Duty Multiplier is 0.5. This seems to be low.

Thank you

stevieturbo
Posts: 834
Joined: Sun Dec 07, 2008 2:04 pm

Re: Direct injection pressure drop

Post by stevieturbo » Wed Mar 27, 2019 9:27 pm

Yes and No.

But there are no big changes in the base tables.....but cumulatively, there are small changes and the end result does follow to a degree.

This is pushing graph scaling a little, but you can see in that area, map, fuel base, fuel final and injector duty....do follow the same patterns as do AFR's get ever so slightly richer at those same areas.

As said, your setup may just be quite sensitive to very small changes in that area. It isnt to say there isnt a problem elsewhere, but it may just need a little fine tuning.

But again, there is no info there relating to high pressure...so impossible to say whether there is an issue there.
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GLDN6
Posts: 42
Joined: Tue Sep 05, 2017 7:35 pm

Re: Direct injection pressure drop

Post by GLDN6 » Mon Aug 19, 2019 12:53 pm

What is it for an engine ?

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