Help with building your Speeduino, installing it, getting it to run etc.
By Cylinder 8
#47081
Yep, standard engine apart from an IPD high lift camshaft, 16T turbo with boost controller and 440cc injectors.


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By Cylinder 8
#47247
For some reason, for the last few days the car's decided it doesn't like starting. Warm or cold. There seems to be something causing the revs to drop about half a second after it starts. If I keep my foot on the throttle it's not much of a problem, but without any throttle input the drop in revs is enough to stall it. I've spent ages changing settings and looking at logs and I cannot work out what it is.

Here's my current tune:
https://drive.google.com/file/d/1j6HfHJ ... p=sharing

And here are two logs from earlier, one with my foot on the throttle, one without:
https://drive.google.com/file/d/1_NEcDF ... p=sharing

https://drive.google.com/file/d/1NiQBja ... p=sharing

Any help is greatly appreciated.
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By PSIG
#47267
Only some oddities to chase that I see offhand. Your 2% TPS log shows fuel PW dropping around half once running, and going lean. The lack of ASE may be part of that, and it appears your ASE is not only 0 above 37°, it also timed-out on previous starting attempts. Be sure to key-off after any stall, in order to re-enable some functions.

In your other log it's on sync loss #12 when it fires :shock:, then I see the voltage drop to 6.9V just before it stalls, and so a couple things to look at there. You may need to re-tune your warm idle to best fuel and timing, pull your GammaE stuff out, and add only what's needed back in for a solid warm restart. Then you can see what extra fuel (ASE and WUE) it needs on cold starts.

I also don't see good voltage corrections for injectors and coils. While it might run "OK" otherwise, stuff like that will fight you during starting and tuning with their odd and sometimes mysterious effects.

These are only a few things that jumped out at me. There may be other issues, but I will wait to look deeper until you can give us more info to help us know where to look.
By Cylinder 8
#47270
Thanks for looking into that, PSIG.

The crank position signal isn't the best during cranking, so it does tend to rack up a few sync losses while the starter motor is spinning before it decides it's happy enough to start. I often don't turn the ignition off in between start attempts, so there are probably some sync losses from the previous times it's stalled included in that log as well.

I had another look at it earlier and noticed the pulse width drops same as you. I've increased the after-start enrichment so it's active at all temperatures and it seems happier now. It still has a slight stumble just after starting but not enough to stall it. It might still need a bit more/longer ASE.

I haven't changed any of the voltage corrections from the original base map, what should I do to improve them?

Thanks again.
By Cylinder 8
#47274
Dagaz_Psi wrote:Is it the green bosch injectors you are running?
https://www.ms4x.net/index.php?title=Fu ... _Deadtimes
I have used those settings and got easy starts.
Do you know what signal filtering caps the Uac is using?
Nice car btw, mines the same color. Did the camsshaft make a big diffrence?
Yes it is, the 440cc 968s. Should I put the 0.919 value in the injector open time box? It's currently set to 1.0.

Do you mean the crank signal filtering? I've tried it on every setting and it doesn't seem to make much difference. Once the engine's running the signal is fine.

Thanks. The camshaft didn't make much difference with the original turbo because it just couldn't flow enough air. Combined with a bigger turbo you can tell the difference though, it pulls much better at high revs than it did with the standard cam.
By Dagaz_Psi
#47276
Test out your opening time you got now and alter between 2-3 squirts and see if lambda is stable. Then adjust open time if needed.
Yes if its using the max9926 as signal filtering it bennefits to switch the filter cap to a 1nf for less syncloss ( helps mostly at higher rpms seen in logs) but it makes for easier starts to in my opinion.

Yeah I had that feeling about the camshaft to looking at it specs. Is it time for a t3/t4 Chinaboy?
By Jakobsen
#47390
Hi

i ran the UA4c on my 944 turbo, and also made an pnp harness on the LH 2.4 ecu, used the stock grounds from LH.

Swap the filter cap to 1nf as mentioned above, that will remove the sync loss on start up, i ran the car whithout any trigger filtering and issues.

my only problem was controlling the injectors on low load, same as you are using Bosch 968, been playing with dead times from 0.7 to 1.1 to figur out what the issue was, but never got it fixed

PS in Engine Constants and map sample method, i would use only Instantanious and event average, that is what worked best on my car, but the instantanious i causing a rough map singnal though :S and only way i could get a steady one was, adding filteres on the signal in TS
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