Author Topic: Please review my setup  (Read 19977 times)

Offline antonch

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Please review my setup
« on: August 22, 2007, 12:51:17 am »
Today I tried to get the VEMS unit to fire up, with no luck. :(

Can someone please take a look at my setup and see if I missed anything obvious? Such as I had the warmup enrichment table was set at 0, the pulsewidths went to 0.

Right now it feels like the engine gets a single fire and then stops. After a few attempts the car backfires out of the intake, its as if pulsewitdhs went to 0. This is when I attempted to have VEMS start the car on a fully warm engine.

The car starts up fine on the stock ECU. Right now VEMS is controlling only fuel as I have a second stock ECU to control timing (for now).

https://webfiles.berkeley.edu/antonch/public_html/M50base.msq

Some info on the engine for reference:
190cc injectors
2.5L I6

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #1 on: August 22, 2007, 10:31:21 am »
Okay then...  As a rule of thumb backfiring through the intake means a lean mixture.

Req_fuel looks to be good, and 50% of req_fuel for your cranking pulse seems to make sense.  Bear in mind that you're firing all banks for cranking Settings->Injector Settings so you're getting a load more fuel than you think.

For an experiment, in Settings->Priming,Cranking,Afterstart set Cranking Threshold to 1500  this will hold VEMS in its cranking phase even though the engine is running.

If that runs the engine for a time we can be sure that theres nothing happening with the fuel pressure dropping off, and look at the afterstart values, so reset the value to 300 to 400rpm.

You'll be making your life easier as this will have got some heat into the engine and the start-up tests will be simpler.

Currently You have no warmup enrichment so the engine is not getting much extra fuel try:
4.4C = 140
15.5 = 130
26.6 = 120
37.7 = 110
54.4 = 105
71.1 = 100


Set Settings->Injector Settings: Fire banks while cranking to Alternate, doing this will give you a load less fuel in the manifold as you're squirting one injector at a time rather than all six...  So you'll need to add more fuel for the cranking pulse, you'll have to juggle the cold and warm cranking values to get the right sort of behaviour as the temperature differs through the season.  BTW the afterstart enrichment scaling of 62.7 seems a bit high, you might want to set that to zero and tune the Afterstart enrichment added value field a little.

Crank the car over watching the PW meter on the laptop.  As it cranks, fires, warms up the PW value will begin to drop, you'll see the fuel PWs reduce slowly through this cycle, which I've described here, try and follow the sequence and work out where the fuel is dropping off too rapidly:


Remember to datalog your startup attempts as this gives a load more information that you can mull over whats happening away from the car where concentration may be easier.

Offline antonch

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Re: Please review my setup
« Reply #2 on: August 22, 2007, 11:52:26 am »
Cool, thanks for a helpful reply.

Are my VE values OK? One "base" map that I found for my engine from a running MS install has them all over the place (30% -> 160%). This are the values that I am actually using. Another VEMS install has them fairly close to each other (80% -> 120%). Since I found a few errors in one of the setups, I am very cautious over using them. The volumetric efficiency value at 600rpm could very well skew my pulse widths. From what you have seen, are VE at 30kpa/600 close to 30% or 80%?

I think I have the T.S. diode installed on my flyback wire from the factory.

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #3 on: August 22, 2007, 03:35:01 pm »
You will find that the VE table will be a lot flatter with VEMS.

Once you've tuned things a bit I would half the req_fuel and double the VE values - it gives you much greater injector resolution.

Offline antonch

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Re: Please review my setup
« Reply #4 on: August 22, 2007, 11:59:42 pm »
OK, I tried your settings. The engine starts up much better now (no back fire and it actually starts!). I made a few changes to my MSQ file, so re download it if you feel you need to.

https://webfiles.berkeley.edu/antonch/public_html/M50base.msq

However, my suspicions that pulse widths went to zero are correct. Please have a look at the log file:

https://webfiles.berkeley.edu/antonch/public_html/datalog200708221539.xls

I looked over the settings again and I am stumped why its doing that  ???


« Last Edit: August 23, 2007, 02:26:03 am by antonch »

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #5 on: August 23, 2007, 11:31:38 am »
Very strange...

Can you download your tables and config files and send them to me?  I'll check that the ALS, Launch control and all that sort of thing is correctly disabled... Settings like those in Extras->RPM Limiters are set to 0, so when the ecu comes out of afterstart mode factors like this are then taken into consideration, to disable the RPM limiter try 25500

This is why all the ecu's sold through me get bench tested with a good setup ;D

Rob

Offline antonch

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Re: Please review my setup
« Reply #6 on: August 23, 2007, 07:49:19 pm »
I downloaded the config files.
https://webfiles.berkeley.edu/antonch/public_html/config.txt
https://webfiles.berkeley.edu/antonch/public_html/tables.txt
I take it you are more used to seeing this in a text format.

Do you think EGO correction could be contributing to this as well?

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #7 on: August 23, 2007, 09:00:20 pm »
With these I can configure my system.  Config and table files are the 'proper' way of saving and upgrading your setup across firmware releases.

I'll have a test of them tomorrow, EGO correction wouldn't have kicked in yet, and should be clamped to a few % change.

Offline antonch

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Re: Please review my setup
« Reply #8 on: August 23, 2007, 11:28:30 pm »
With these I can configure my system.  Config and table files are the 'proper' way of saving and upgrading your setup across firmware releases.

I'll have a test of them tomorrow, EGO correction wouldn't have kicked in yet, and should be clamped to a few % change.

I am running firmware 1.0.73 if that helps. Thanks for providing the support. I can't wait to get my setup up and running.

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #9 on: August 24, 2007, 06:41:46 pm »
Okay... I ran that config up and found that once RPM got to around 2?00 rpm that the fuel would cut.
So I've turned overrun_fuelcut off and set all the revlimits to 25500.
If the TPS is 0 and RPM rises above the fuelcut value then the fuel gets cut.

Also what is controlling your fuel pump?  All of your outputs were set to INJFET 0 which meant that EC36-pin20 remained high at all times, so I'd check the injector operation on that channel.

http://www.vems.co.uk/VEMSConfigs/antonchconfig.txt
http://www.vems.co.uk/VEMSConfigs/antonchtables.txt

download these, rename to config.txt and tables.txt, run the generate-config12x12.bat, then upload-config.bat

Offline antonch

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Re: Please review my setup
« Reply #10 on: August 24, 2007, 08:15:19 pm »
But if you check the logs the RPM never got to 2x00 RPM. The max is 1255 and there was a fuel cut before that.

EC36-pin20 is wired up to injector 4. I am not controlling the fuel pump, as the OEM ecu seems to do a pretty good job with that. I'll check all my settings and change the assignment of INJFET0 to something else.

What firmware version did you try your setup on?

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #11 on: August 24, 2007, 08:22:58 pm »
Just reporting what I found on my setup running 1.0.73 as thats what you were using...

You can just use what I've sent you, its tested and should work fine.

Offline antonch

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Re: Please review my setup
« Reply #12 on: August 25, 2007, 09:30:16 am »
Just reporting what I found on my setup running 1.0.73 as thats what you were using...

You can just use what I've sent you, its tested and should work fine.

Sweet, it worked! Just spent a few hours with a buddy trying to get the VE table dialed in. I quickly found out that the stock injectors run out of steam very quick on a turbocharged vehicle (I tried my best not to exceed 85% duty cycle). I was very surprised how linear the maps were. You could literally copy the values across the board and still have the car run. If anyone can remember Autronic's one cell video this is what it reminds me of.

I think I might have to relocate the IAT sensor though (its right before the TB). As the VE tables fluctuates greatly with either MAT or CLT changes, not sure which. It gets a lot leaner when I drove the car on the street rather than the parking lot. Will do a few more pulls tomorrow and see if I can diagnose the problem better.

Offline rob@vems.co.uk

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Re: Please review my setup
« Reply #13 on: August 25, 2007, 11:51:34 am »
A flat VE table on a Speed Density system shows good injector control and proper interpolation (thats why we need less points in our maps) ;D

I'm a little concerned that you're sharing sensors with another ECU - that can cause trouble :o
« Last Edit: August 25, 2007, 12:42:44 pm by rob@vems.co.uk »

Offline antonch

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Re: Please review my setup
« Reply #14 on: August 26, 2007, 11:40:50 pm »
Ah figured out my problem with it running lean on the street. My buddy stalled the car as we got out of the parking lot. I forgot that the tables  needed to be "burned" to stay in memory, couldn't do that when the car was moving.

I was wondering if your car had any issues shutting down. When I turn the key to the off position, the car runs on its own for a bit until it finally dies (few secs). It's a bit like preignition but it shuts down fine on stock ecu.

If I turn off the fuel pump right before via a switch that I have installed in the cabin, it shuts down a lot nicer.