understanding tip in and tps/map dot

[nathanhardy]

I cant get the log with it doing it but, here is the screen shot! can you shorten logs?

[kjones6039]

I also need advice on setting my over run fuel cut I change it but I think I need to set it to come on right below idle.

I would turn overrun fuel cut off until I got the tune better sorted, if this was mine!

Ken

[kjones6039]

I cant get the log with it doing it but, here is the screen shot! can you shorten logs?

Yes. There is a function in MLV that will do just that!

Ken

[nathanhardy]

thanks ken! I tried turning it off once and it really loaded up with fuel.. I know for a fact that vr6 motors had over run fuel cut im just not sure if I have it set the best way, I don't really see why turning it off would help if I know it's got to be on especially when its that way from the factory and veal tunes it anyway.. but im always ready to learn does it just not catch it as fast with it on and running autotuning

[nathanhardy]

so it's towards the end of the log that things seem to get funky you'll notice every thing is fairly smooth then it gets jerky

[kjones6039]

I tried turning it off once and it really loaded up with fuel..

Strange...... Let's see what the experts say, but turning off overrun fuel cut should not not have any effect on basic fueling! Just my opinion, of course!

I have only had a moment to look at your log, but I see several things that raise serious questions (once again, IMO only). I will address those later this evening unless, hopefully, one of the guru's happens by.

Ken

[nathanhardy]

I tried turning it off once and it really loaded up with fuel..

Strange...... Let's see what the experts say, but turning off overrun fuel cut should not not have any effect on basic fueling! Just my opinion, of course!

I have only had a moment to look at your log, but I see several things that raise serious questions (once again, IMO only). I will address those later this evening unless, hopefully, one of the guru's happens by.

Ken

let me be more clear it was jerky after deccel go back it to it and I had to push the clutch in and rev it to stop the jerkiness, with it on it does not do it at all! except at the end of my log!

[16vboost]

OK I finally understand what you're concerned about. It's the problem at 2279, 2293, 2308, 2344, etc. I thought this might have been electrical TPS noise, but now I see that it's not. See the TPS signal bouncing up and down? See the MAP signal following it? This means that the throttle plate is actually opening and closing suddenly and the MAP is following it accordingly. Even when things are relatively smooth, like at 1561, you still have some oscillation in the throttle plate that is "real" because it is translating to oscillation in the MAP signal.

You mentioned a few posts back that you needed a stiffer throttle spring. You do! I think you have to fix this mechanical problem before tuning further. That alone will solve all of your unwanted AE triggers and in fact you can probably go back to a higher lag number for TPS and lower TPSdot threshold for AE if you get the right spring.

What car / engine is this? Why is the throttle spring too light?

-Alex

[nathanhardy]

i think your right Alex because once it gets going it keep getting worse cause it jerks hard enough to make me push the pedal... so its a vr6 with a custom intake I made im using a 70mm mustang 5.0 throttle body is has its own spring and I added one too but i'll try a heavier one! so I made some changes tonight with all the info ive gathered from these post and the ae has gotten much better also been veal tuning without ego. my car doesnt like anything more then .5ms on the scale and that lean spike I bet money on was the extra/too much fuel cause a rich miss.i'll post a new msq and log.. I'm still having a issue with mat correction or baro or something because my idle always needs afr adjusted and veal is always changing things for day to day night to night how can I tell if its close enough to the % you gave me earlier to call it good and tune ego?

[nathanhardy]

okay gentlemen the car is running much better now! with much changes comes much success! lol

I tweaked just about everything today since I had the time. cleaned up my ve spark and afr table bins, over run fuel cut, tps ae. tune a lot with out ego on till I got it to with in 4 cells on mlv analyze then turned back on.. seem great till driving up my street I got on it a bit probably shouldn't but did and it seemed to stall mid boost enough to trip my oil pressure light I'm not sure if its mechanical or electrical but the rpm on the dash went to zero. @ 1138 in the log also what is causing the lean spikes?

[kaeman]

ok, Nathan.
1. turn off over run fuel cut. You can turn it back on if you feel the need when the engine runs good.
2. raise your accel enrich threshold. my lowest accel setting is like 200%
3. shorten your accel time to something like .25 sec. not 1 like you have and see if that helps.
4. change your value for fuel accell enrichment rpm to something like 5000 and 5000. that way the accel enrich works until you are up in the rpms
5. turn on your ego corrections by changing the temp threshold to something like 160.
6. also give the controller 10% authority, and a 1% step, then your o2 corrections will actually work.
7. I would try the MAT adjustment % found in the motec set up manuals. it helped on my engine, the ideal gas law was pulling too much fuel for my setup.

Good Luck. I posted my msq in the other thread (mine) where you asked about my MAT settings.

[nathanhardy]

Okay I will do exactly what you said to today and I'll report I am also going to install the better spring on the t body, I notice when I adjusted my rpm ae limits that's when it started to really get better I just didn't have a clue where to set them, are there any really good clear step by step books out there that cover everything ms does and how to get the results I'm looking for I appreciate all the help I get but I'd like to help back as much as I can too

[sdtib]

There is a good tutorial for tuning AE on DIY Autune
http://www.diyautotune.com/tech_article ... tuning.htm
I followed these steps and so far have gotten good results. Mine still needs a little work on tip in from a dead stop but works well everywhere else right now.

[nathanhardy]

any ideas what cause the motor to stall in boost?

[16vboost]

You've got sync errors when the stall happened. Have you ever run the engine that high in the RPM before? You're using the stock 60-2 VR sensor? Maybe you need to adjust the VR circuit.

Before you tune much else, turn down your fuel pressure. I see that you're only at 46% duty cycle at 130kPa and 5600 RPM. And you're idling at 1.8ms and PW gets as low as 1.2ms during over-run. You need to try to increase the PW as much as you can. These extremely small pulse widths will cause 2 things: 1. Your injector opening time (and correction) must be 100% spot on to avoid your constant variations in AFR. As MAT, Baro, or other corrections are applied to your VE table, the amount of PW that these corrections add assumes the dead time is correct. This is less critical if your dead time (and any associated error with it) is a small fraction of your PW, but if your dead time is a large fraction of your pulsewidth, so is the error associated with it. 2. You're operating your injectors in the non-linear range. Meaning that the amount of fuel that comes out for a commanded PW is not directly proportional to that PW. There's no way to get fueling right under these conditions and you end up having to idle at 13:1. Also, for very short pulse widths, the injectors just don't open. Notice how you still get "over run fuel cut" even with it turned off. This is because the MAP and corresponding PW are so low during over run that no fuel comes out.

So I'd take care of the sync problem first, and then sort out your req fuel so that you're near 90-95% duty cycle at max boost / max RPM. I know 80% is recommended but I think that's ridiculous for a turbo motor.

Then get your VE map re-tuned, then EGO, then AE, and if you're still not satisfied EAE.

-Alex

[16vboost]

Oh and do you have a 3.1L VR6?

-Alex

[racingmini_mtl]

... then sort out your req fuel so that you're near 90-95% duty cycle at max boost / max RPM...

That's not a good idea to go that high because then you end up in another non-linear region and the injectors don't have time to close and open between pulses (depending on injectors and RPM). Also, you don't have any margin if the conditions under which you run mean you need more fuel. That will also create a lean condition if you get some over boost for whatever reason.

Using 80% might be too low but 95% is much too high in my view.

Jean

[sdtib]

You've got sync errors when the stall happened. Have you ever run the engine that high in the RPM before? You're using the stock 60-2 VR sensor? Maybe you need to adjust the VR circuit.

Not sure if this is relevant because I am new at this too but...
My car also has a 60-2 toothed wheel (Hyundai V6) and I was getting synch errors above 6k rpm's. Adjusting the VR trim pots solved it for me. I had them set at the defaults from the build instructions, R52 all the way counter clock wise, and R56 six turns clockwise. It turns out my car likes R56 at 4 turns. I got a real noisy signal at about 2 turns which cleared up at about 3.5 turns so I went another half turn and took it out for a drive, After that the signal was clean all the way to red line.

[nathanhardy]

You've got sync errors when the stall happened. Have you ever run the engine that high in the RPM before? You're using the stock 60-2 VR sensor? Maybe you need to adjust the VR circuit.

Before you tune much else, turn down your fuel pressure. I see that you're only at 46% duty cycle at 130kPa and 5600 RPM. And you're idling at 1.8ms and PW gets as low as 1.2ms during over-run. You need to try to increase the PW as much as you can. These extremely small pulse widths will cause 2 things: 1. Your injector opening time (and correction) must be 100% spot on to avoid your constant variations in AFR. As MAT, Baro, or other corrections are applied to your VE table, the amount of PW that these corrections add assumes the dead time is correct. This is less critical if your dead time (and any associated error with it) is a small fraction of your PW, but if your dead time is a large fraction of your pulsewidth, so is the error associated with it. 2. You're operating your injectors in the non-linear range. Meaning that the amount of fuel that comes out for a commanded PW is not directly proportional to that PW. There's no way to get fueling right under these conditions and you end up having to idle at 13:1. Also, for very short pulse widths, the injectors just don't open. Notice how you still get "over run fuel cut" even with it turned off. This is because the MAP and corresponding PW are so low during over run that no fuel comes out.

So I'd take care of the sync problem first, and then sort out your req fuel so that you're near 90-95% duty cycle at max boost / max RPM. I know 80% is recommended but I think that's ridiculous for a turbo motor.

Then get your VE map re-tuned, then EGO, then AE, and if you're still not satisfied EAE.

-Alex

will do! my fp is set at 4 1/2 bar. what would a good starting point be 3 bar? I never realized that would cause a problem but now it does make sense! over run fuel has never been off in any of those logs but will now because my understanding is coming around... so should i shoot for 90% duty then.. what if I want more boost I guess run a different msq if that ever happens for know my max is 250kpa wont it be at a higher duty at the boost?. for my vr pot I have them set fully counter clockwise I was told by the vr6 pros that those are the needed settings so unless its vibrated it should still be there... whats weird about it is my oil indicator on the cars dash comes on so ether the motor is locking to a dead stop or its electrical on those sync loss.. as far as I can tell it only happened that bad twice

[nathanhardy]

come to think about it could it be the boost blowing out the spark its getting close to my soft rev limit? oh and yes stock vr sensor.. so to increase my injector duty do I just turn down the fuel pressure... the way it read to me I would need to lower my required fuel too, 7.1 right now and that is what it calculated.. its a 3.0 vr6 were you asking if I had a extra block? alex