It goes SUPER lean when we let it bounce. Anyone know how to fix it?


The Fuel Cut TP is at 9
Wait time is 4.5


Hold is 6350 RPM
90% and 100% Throttle = 62.0

Limit is 6900
90% and 100% Throttle = 66.0

 

Isn't it supposed to be lean on a fuel cut rev limit?

 

Look at the Injector duty cycle though, I don;t think it is suppose to spike like that.

 

Why not? That is what a fuel cut rev limiter does.

 

Heh, sorry. I wasnt thinking too much today. Weekend was kinda crazy. Makes sence.

 

LOL..."why does it go lean when the fuel is taken away".


JFWY, those logs are hard to read.

 

Hungover FTL...

BTW its still kinda lean when driving so we are gonna keep trying to add fuel past the stock limit. Those logs were done in neutral.

 

Is the only thing you did to rev past the stock rev limiter add fuel (increase IPW). BTW is this on your car (4th gen) or something else?

 

2000 Turbo Max.

 

I still could be wrong, and I almost didn't even respond to this thread because I haven't used the EU and I'm not 100% sure of what I am seeing in those pics.

 

Why I posted, first time messing with the EU in person for me.

 

I imagine that's on jeremykedel's car.

There are 2 maps that come into play for the rev limit.. the hold/limit map and the INJ map. Basically it is a matter of adding fuel to the INJ map and setting up the hold and limit point DC's/IPW's.

It's looking like I'll get my car back out of storage next weekend and I intend to do some more testing, probably going from stock cut at 6500 up to 7500 or so. First time around I was misled by Greddy as to how it worked so didn't get the proper results. Alex did good work but I want to rev it up a lot higher on my own car. I'm also going to try the 2-step and re-test my ignition stuff as I'm suspicious that the timing control on my EU is defective.

 

Can you elaborate as to what the "hold and limit point duty cycles/injector pulse widths" are? what does "hold and limit point" mean?

 

Coincidently, I have been looking into the EB (emanage basic) the past few days trying to determine if we can actually use it to extend the rev limits on the DE-K. So far I haven't found a reason as to why it can't work.

 

Well the hold point should be the rpm right before the factory fuel cut, the limit is the new rev limit point. You have to specify some load points at those rpms (ie maf or TPS etc vs either DC or PW). THen the wait time is how long this map will stay active... the max is 5 ms right now. Greddy programmed it that way because on many cars, the fuel cut only occurs for a few ms, after which the factory ECU will resume fueling. The Hold and Limit PW's you specify are then used to provide fueling (using interpolation), just for the time the map is active. After that point, the intent is that the normal +/- INJ map resumes control.

However our ECU's will continuously cut fuel past the stock limit, so if the Hold and Limit map is set by itself only it won't work, since it only stays active for those few ms, expecting the ECU to kick back in. So you get that sharp sawtooth pattern as you bang up and down on the limiter. So what we have to do then, in addition to the Hold and Limit map is to crank the INJ map way up just at and past the stock cut point, so that it provides fuel while the ECU does not. So for example, you might be adding a few % points of fuel up to the stock limit, but after that point, you have to add back in the full DC/PW amount you need (eg 70%+)

I'm now wondering though if we can do this without even using the hold/limit map, ie just off the main INJ map. I should be able to post some more logs next week showing some settings also.

EDIT: SR20 you are thinking along the same lines? ie-just add fuel past the limit since ign is not cut...

 

Exactly, I learned this lesson ten years ago when I over revved my SE-R with the DPI nitrous system. If the ignition is still there, all you need is fuel. And injector timing does not need to be precise like ignition timing. An ugly batch fire would work fine if you had to use it.


I have been looking at a few different ways to get through that 6500-6600 transition. Adding some IPW at 6500 is probably one of the easiest methods.


If I can make this work with the EB, all of the DE-K owners would benefit from a relatively cheap rev extension.

 

Yeah that's the only glitch is going from adding say 5 or 10% fuel to suddenly adding 70%+ in the space of 50-100 rpms. The more resolution points the better. Hopefully having a more accurate rpm pickup on the EU (with the crank signal) will help in consistently hitting the right ramp up point too. I must say I do like the ability to completely customize the rpm setpoints. Some regions of the map don't require as many breakpoints compared to others so it gives you the ability to widen the interpolation gap in some areas and shorten it right down in others (such as at the rev limit).

 

sloppymax's 2k1 AE auto appears to be limited right at 6500 according to the VAFC-II. So there might not even be a problem with the transition (gap) if we start it at the full amount at 6500. However there would be an interpolation issue if it wants to start from zero at 6400. And I haven't seen anywhere to add a hold point with the EB. But either way, if the ignition is there I will figure out how to make it work, even if it requires a balancing act in conjuction with the MAF output.

 

Right at 6500 huh well that's interesting. It's more like 6450 on mine. But I guess worst case scenario you could just ramp up a bit early. You'd get a rich spike for a couple hundred rpms but it shouldn't make much of a noticeable difference in engine smoothness or acceleration. It'd be better than having a sudden lean dip for sure.

I think on the EU the issue is probably more to due with the accuracy of the rpm reading at this point, since the setpoint resolution can go down to 50 rpms. IIRC correctly Alex was having some problems where it wasn't always hitting the ramp up at the right spot just due to fluctuations in the rpm signal. Hopefully having the crank input will improve that.

 

The hold/limit,is the injector duty cycle.I added fuel and it is still a lil lean,I am trying to figure out the two step now.

 

Here is a little document I made over the weekend. There is still much to add though. Maybe some of you can offer some suggestions.

http://vq35de.com:2002/A33x_ECM.pdf

 

You've got ballz to be doing that on a FI motor.

Don't use duty cycle, use duration, and make sure you use the Injector Add map for when the RLC map cuts out. Just be careful of when they overlap because your injectors will go static and the engine power falls flat.

 

SR20DEN/Dandy - Timing is based off the IPW/RPM, so just dumping fuel isn't the solution because timing falls off.

 

Yeah I added fuel, and the autotune is trying to add fuel too.

 

Your two logs above are what mine looked like until I switched from Duty Cycle to Duration and adjusted the Add Inj map RPM points.

I wouldn't use the Autotune for that...just to pull fuel once you know you are way rich.

 

Well the Autotune is set to tune the car to 11.5 in Open loop so it keeps trying to. It does a decent job of it.

Yeah, should I attempt to add timing after the stock revlimt?

 

That is what I needed to know. So how long does the ign. map continue if it does at all? Any more success with raising your rev limit?

 

The stock map at least goes to 6900 because on those logs the timing on the emanage map is at -1

 

Without being able to log timing, I wouldn't on a FI car. Who knows whether you are adding a little or a lot?

My car NA/stock did seem to increase RPM or at least hold RPM after the stock limiter once I added 5-degrees. 10-15 didn't seem to make much difference IIRC.

 

I don't know...

No more success/failure, since I haven't had a laptop.

Friday night I pulled out of a parking lot and the engine kept trying to die and wouldn't rev, while pumping smoke out the back. I had to unplug the harness and it ran fine...still haven't figured out what happened, ie EU, wiring, or software.

I did notice the orange blinking status light wasn't blinking, so that's not good.

 

Does anyone know what the maximum retard is on the EB, can it go as high as 60º? I have a morbid idea.

 

+/- 20 degrees...no luck Matt.

http://www.mohdparts.com/emanage/man...manual/028.JPG

 

And are people claiming that the timing advance doesn't actually work with the EB on the VQ30?

 

Did you verify what the timing was with an OBD scanner past the rev limit? Do we know for sure if/how much it falls off? If the ignition continues past the stock rev limit with zero fuel then there's got to be at least some base timing still there or perhaps it's programmed in that region independently of IPW. But as long as there's an ignition signal then we'd just have to add more timing if need be with the EU (maximum is +/- 30 deg). Granted, on other piggybacks that can't advance timing well then it could be a bit different problem...


I'm wondering also how far the stock ignition map goes. I had hoped Alex would go higher than 6900 or so when he did it (no offense Alex ). I'd like to extend the limit all the way up to a good 7500 or so to see how far it will work. My gut feeling is that the ignition map will go at least that far but I won't know until I do it. I should be able to do this on Saturday when I get the car back.

 

I am scared to rev his car that high other wise I would.

 

I think that was before the updated firmware when we were using diodes in the coil wires. the diodes prevented advancing.

 

So the EB doesnt melt coils anymore?

 

from what I heard the updated firmware supposedly corrected that....do I trust it, NO. I re-wried in Redmax's EB after we converted his car to 96 harness and I still used the diodes along with the new firmware...better safe than sorry IMO.

 

Hmm, anyone have spare coils to test out

 

Yes, that seems to be the agreement because of a lack of crank/cam signal input.