Instead of easytune we are having the high impedence injectors made as we speak. Our first test set will be here today.

 

An 'easy tune' is not going to change anything.

That is the kind of thing people do when they don’t have the ability to characterize an injector. Because they don’t know anything about it, or what really causes the problem, they try to fix the wrong thing.

Let me get this right. You buy an injector with crappy response, and the wrong impedance for your ECU because it is cheap. Then you buy a magic box that doesn’t fix the problem, and a peak and hold injector to make it even better. Cheap injectors plus 2 expensive band aids equals a lot of money spent for something that still doesn’t work right.

ID has a car used for product testing. It is more heavily instrumented than most engine dyno cells. It has an on board power supply with variable voltage and can run the injectors anywhere from 8 to 24 volts. The purpose is to test our data in the real world, not to drive around with a fixed voltage. Want to guess what happens if we drive it around with 24 volts on the injectors, and the wrong dead times? It still doesn’t properly account for changes in atmospheric conditions!

If you boost voltage, and the car runs better as a result, it simply means that the car was improperly tuned before, AND changing voltage changed the mixture to something more favorable. If the dead times are incorrect, the car runs the same regardless of voltage.

The motor doesn’t care how much voltage is firing the injector, or how much time the valve takes to open. All the motor (combustion) knows is how well is the fuel atomized, how homogenous is the mixture, and what is the air fuel ratio. If you have gross non linearities, the air fuel ratio will be all over the place. If you increase the voltage, you still have non linearities, you have just moved them in time.

Look at this graph and explain how higher voltage has solved anything. There is absolutely nothing happening that will not be accounted for with proper injector dead times. The rest of the non linearities that are present with that injector are still there, they can not be fixed with a magic box.



The problem with injector peddlers is that they are not tuners. They don’t know much about tuning a car, and so what little bit of data they do have for the injectors means nothing to them. That’s why they do stuff like this.

Paul Yaw from Injector Dynamics will be giving seminars at the Performance Racing Industry tradeshow in Orlando entitled “Understanding Your Fuel Injector. The seminar is sponsored by Motec and is free for PRI attendees. For anyone who wants to know how this stuff actually works as opposed to just being armed with “internet knowledge” come to the show and attend the seminar.

The seminar schedules will be listed on the PRI website shortly.

Back on topic....

Has anyone monitored fuel pressure and fuel temperature?

I have not heard of any of these issues with anything other than the stock ecu, which makes me believe it's not related to vapor lock or anything like that. Has anyone had these problems with an AEM or any other system?

Skunk 2 just released their composite fuel rail for the EVO. If someone is interested in giving one of those a shot, i'll help them out on the rail cost. That will drop fuel temperatures at the injector significantly. The problem could be fuel boiling in the rail, though it would be present with any ecu if that was what was happening.

 

tony, you are pretty much a injector peddler yourself. You come here in periodically and post some would be good tech that makes your injectors seam like magic. Yet You need to read all the posts to see there is a genuine problem with these injectors. And your graph itself show the FIC box would do well to improve linearity at low pulse widths of a crappy injector. at starting voltage the graph is non linear form 2.4msec and lower at 10volts. that non linearity improves to 1.6msec and lower at 18volts. That is a huge improvement and very relevant to improving an injector performance at low pulse widths. The second thing the FIC box does is eliminate the battery compensation curve. since the injector always sees 18v that curve is now a line. this further makes it easier to dial in the correct latency values. In short you would be better off not insinuating we dont understand how the latency value affects how an injector works. its not that hard a concept to grasp. now go back to peddling your injectors so that those of us who are having issues here can figure it out.

 

I'll test the pressure and temperature tonight Tony.

I'll email you on the rail. Thank you for your input. Much appreciated.

 

I did a very simple test this morning. got the car hot then felt the injector body at shutdown. then again at 25 minutes, there is no heat build up in the injector at all. so it is not a vapor lock issue. the injector or fuel is not getting hot enough.

 

While I may be an 'injector peddler', the difference is i'm also a tuner and understand this stuff and use it myself on a daily basis.

First off, there is not a problem with our injectors, there is a problem with your car and/or ecu.

Second, you must not be interpreting the graph correctly. If you have the proper battery comp values in the ecu, all those lines will overlay as 'effective pulsewidth' rather than 'actual pulsewidth'. Battery comps are not something that should be 'dialed in', they are something that should be properly measured and input accordingly.

You can't look at the non linearity related to pulsewidth, you have to look at it related to fuel flow. If you look again at the chart, you'll see that the non linearity exists almost identical with regards to fuel flow at any voltage.

 

to make the above statement more clear, the graph posted above does show areas that are "linear" but the slope of those graphs is not 1. so the fuel flow at 3msec @16v (500cc/min) does not equal 2x the flow at 6msec@16v (which is ~1100cc/min not 1000cc/min). Thus the ecu calculates fuel flow adjustment that are incorrect regardless of the voltage used.

 

Make sure you guys keep this CIVIL!!!

 

94AWDcoupe,
I asked Tony for help... that's why he's here. I ask Tony for help not because he sold me my injectors, but because he's got the experience and knowledge to figure this out. I've followed Tony's fab, wiring, tuning, racing, etc on Honda-tech since about 2004... I know he's not a one trick pony or an "injector peddler" as you called him.

You don't run 8's on hopes and dreams BY YOURSELF in a Honda without truckloads of ability.

 

Like a said... keep it CIVIL, or I'll have to be UN-CIVIL.

Everyone's input on this issue is appreciated by most here. The issue needs to get figured out. Most here run the OE ECU. Most here have little choice for a daily driver, and before the next president, EVERYONE may have to in order to have a legal road car.

So, this needs to get figured out as it stands. So bickering will not get started, however, respectful disagreement is expected.

 

we're all friends here Zeus... I don't know who called you in, but I honestly don't think anyone's panties are bunched ATM.

 

I can monitor fuel pressure at the rail - not while driving though, its just a mechanical gauge i installed at the fuel rail because I originally thought I was having FP issues.....one thing if I had access to a some kind of laser temp gauge to see the temp of my fuel rail vs. dan's fuel rail after both ban ran to optimum temp and shut down for 30 min w/ hood closed - this might tell part of the story if fuel boiling is an issue.

dan and I talked about the fuel rail being an issue as hard as it is to believe I would not be surprised if that is where the solution is. I would be willing to test this, you can pm me pricing if you wish. I have been working on this more than anything since April with every testing procedures, ideas, table modifications, and parts replacement that I or anyone I know that has helped me can think of....I know dan is running out of ideas as well as me.

One thing I do know is dan's car has the manifold and O2 housing wrapped with dei exhaust wrap and dei high temp wrap coating....now this would lower under hood temps vs. non-coated like mine - but to what degree and is it significant enough to cause this issue to not happen in his car? If were talking temps this is a clear difference from our cars...

Also I don't like the fact that the injectors are solely being blamed here and Tony getting beef over it (he is here to help and share his knowledge) - I for one do not believe the injectors are at fault. I have had (2) different sets with the same problem and (1) set went into dans car before being sent back to Paul and they worked 100% fine, also I have done a lot of searching on other car boards that run these injectors and this issue is non-existent. It is something specific to this application and for some the problem doesn't exist - I know of (2) evo's without the problem now. Through the testing I have done and swapping of another set sent from paul yaw direct I don't see the injectors being the problem - the question is what part/parts are causing this issue on an evo vs. other cars?

 

I'm all setup for logging fuel pressure with a Kavlico sensor threaded into the fuel rail. I've actually had it ready for quite a few months, but haven't taken the time to get some shutdown logs. I guess I'll start on that tomorrow.

It would seem odd if vapor lock was causing the issue. Why these injectors and not the stock injectors?

 

That's what keeps leading me back to thinking it's ecu related. That and the fact that the guys with aftermarket ecus don't seem to be having the same problem. That's me assuming based on not hearing anything of it, does anyone know of anyone with these issues with an EMS or something?

You guys have also noticed differences in this when using different fuels, right? E85 and gas? Not that it points in one direction more than the other, but something to consider. Obviously different boiling point in the different fuels as well as different fuel flow requirements.

 

I have the magnus IM on my car... and I run the phenolic spacer. I would think my car is less likely to have this issue if it were a fuel boiling issue.

Is there a possibility that the wiring was done differently on Dan's car? Either on accident or on purpose?

Could this be ground strap related? Does dan's car still retain the all the factory equipment? EGR,Evap, etc.