Question about injectors
Time open on a larger injector into various manifold pressures will vary greatly between different injector sizes. 3ms on a 60# injector doesn't equal 3ms on a 30#, and because flow INCREASES with more pressure in the manifold, how do you "figure that out" through trial and error without testing it?
Sorry, but a scanner simply isn't enough to find these values from one injector to the next. People like Greg Banish spent years finding this data. Why would he bother if your method is so superior? If it is why don't you sell a DVD or have a book out yet? Why does GM even bother with it? Riddle me that smart guy.
This is why you have no friends on this forum. You just have to always disagree with solid advice. Maybe the OP doesn't have such a tuner as "advanced" as you are in his area. And by that I mean jacked up for not using reliable data.
Sorry for mucking up your thread OP. Don't listen to this dude. Get some injectors with good data so you don't run into problems later. It's worth the extra 10 whole minutes to find some that are tested and come with reliable data.
With this in mind, it is possible to find the injector open delay by dialing back fuel injector pulsewidth until erratic, often random misfires, behavior results from the engine with minimum injector pulse. I always do this even if the data is given anyways since it is important to know your actual injector operating range on the exact engine you are working on, I never rely on "plug and play data". Since stand-alone computer systems do not rely on Fuel VE table for ignition timing and transmission shifting the way factory LS computer does, I also use this as an opportunity to normalize my basemap idle fuel injection values. That is, I prefer them to all read approx 1.005ms. So if my voltage curve during testing was 1ms and I find that it takes .885ms in the fuel map to get misfires, my total ontime being around 1.885, I find my injector delay to be -1(1.005 - 1.885 + error), where error is a tiny number, usually .015 or .025 any number I choose to remove myself from the troubling conditions presented at exactly 1.885ms after some testing. I make sure that with error there is never any condition under which the engine behaves erratically and that by removing the erratic injector behavior ensues.
It is worth mentioning now that we've come this far that once you get solid data at that voltage, to disable the alternator or dial back alternator duty cycle is a solid way to dial in the injector delay for conditions when the alternator dies or voltage drops . Since the line between them is close enough to linear, it will make a second data point to draw a line with.
Injector delay is insignificant at large injector pulsewidths. i.e. losing 2 volts with a poorly drawn injector delay curve isn't going to cost a significant amount of fuel, especially with a large injector. Many stand-alone ECU (Haltech & AEM) shut the alternator off at high engine angular velocity (RPM) anyways. The injector delay "tuning" schedule is primarily for convenience and low-speed combustion quality/consistency, as having injectors randomly not open around idle speeds is inconvenient and perhaps annoying, but certainly not fatal to the engine.
Last edited by kingtal0n; Mar 22, 2018 at 09:05 PM.
that guy walked into a junkyard on jan. 1st 2017 having never seen an LS engine in person before, and over the course of next 4-months, in the outside air, with no shop/lift, took an LS from a junkyard refurbished the top part and put it into a Nissan, wired it, tuned it, turbo'd it and put about 7,000 miles on it by 2018 while working out the bugs (after all, its his first LS engine, gonna be bugs right). And then posted every step it took for the benefit of others.
The point I've always been trying to make there is, you don't need to own or ever have seen an LS engine or it's tuning software... to know how to work on, install, and tune LS engines and their software. I knew how to tune an LS before I saw one. Its offered a few surprises but nothing beyond that which I was already aware that a digital processor could do.
The Eight piece price SHIPPED to your door, USA, by USPS.
Lance
I'm really tired of responding to people that want to reinvent the wheel, so I'll respond to someone else that seems to show a bit of sense. Thanks for the reply.
You are literally talking about less than 1ms or .001 seconds worth of fuel, hardly enough to qualify for such exasperated internet postings. Spend your time more wisely IMO
heres me, letting go
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My guess is "Long" for your needs, send the money for payment, my E-mail is a common method, AND send the ship to address, delivery will be by USPS.
Thanks for your RFQ.
I MANUFACTURE EMS, I KNOW these reasons !
#1 I fit a 46 AMP Mosfet Injector Driver, each channel with NO need for DEAD TIME calibrations. The GM PCM use a Monolithic EIGHT CHANNEL IC with ONE AMP drive requiring Dead Time Calibration.
I have an object of V-Batt calibration for Injector Pulse Width change based on system voltage with common calibration # of 60us-75us.
This is VERY Important for Cold Start/Fans/Air Condition caused by charging system voltage change.
The injector Armature travel "read" is VERY easy when a Scope is used.
This information is used to calculate the Min-PW of the measure fuel injector.
Lance
I'd wager that with the proper data, one could make a 15 year set of EV1 injectors run better on an LS3 (or any ECU, really) than some random unknown newer design without data.
STOP WASTING $$$
Your requirement of an EARLY EV-1, "long", fuel injector was met by a Bosch product, the modern thin injector with 14 Ohms.
This is a more expensive item, though YOUR payment made was for Denso EV-14.
Thus you got THAT price as quoted, I am fine with your case.
I should add that MOST LS engines use injectors with the EV-14 (American Car) connector.
Many LS injectors are the "short" item.
Thanks for the pictures sent to my direct E-Mail as there was NO mistake.
Lance
Injector delay is insignificant at large injector pulsewidths. i.e. losing 2 volts with a poorly drawn injector delay curve isn't going to cost a significant amount of fuel, especially with a large injector. Many stand-alone ECU (Haltech & AEM) shut the alternator off at high engine angular velocity (RPM) anyways. The injector delay "tuning" schedule is primarily for convenience and low-speed combustion quality/consistency, as having injectors randomly not open around idle speeds is inconvenient and perhaps annoying, but certainly not fatal to the engine.
I was very clear that it was important at low pulse widths for convenience and low-speed combustion quality/consistency and insignificant at high pulse widths. These days we have a wideband in the car which tells us right away if the a/f is wrong or not. So this is a non issue, i.e. you can have poor injector delay information and still have a good a/f ratio because the base map will makeup for the difference if you are actually tuning the vehicle.
2. You should not be using closed loop at idle with a big cam, unnecessary and leads to these kinds of ridiculous complications
3. I never use closed loop in any of my cars at any time anyways. If you know how to tune an engine you won't need it or want it either. It would get worse fuel economy with computer control closed loop in my application (daily).
4. You have to use a little common sense and experience when tuning low speed with a wideband. 100+ cars and I've never had an issue following it at idle, even with enormous camshafts etc... I know tons of tricks for this. If you want some tricks lmk Ill post a couple but theres like 10 I know of,
A: Just off idle the pulse will be similar to idle. So if the wideband is giving you **** with no load/neutral at 1000rpm, simply put it in gear and let the car roll "load a little" to 1200rpm and check your injector pulse / wideband behavior. As the engine loads it will get smoother as more fuel is injected and the average improves. Apply the brakes to further assist with low rpm / load condition.
B: reducing injector pulse until the engine misfires at random is a clear indicator that injector on-time is at it's minimum. This is important because a large injector with poor low-pulse performance is going to give more trouble with idle speed behavior, especially if the a/f being displayed is still too rich and you cannot reduce pulse further for example. This basically sets the minimum pulse FOR YOU (as opposed to any reading on the wideband gauge, which is meaningless at this point because you can't reduce pulse enough to get it where you want it) Again I know work around but... space concerns ... just ask
C: &C
A year ago you didn't even know what a damn OBD2 port was and they have been on vehicles since what....1996?
How can you have tuned a 100+ cars and not immediately know what an OBD2 port looks like?
Speaking of common sense.
You continue to be called out post after post and continue to "try" to argue your point. Have you even thought about why that only seems to happen you?
There is a reason for needing/having/wanting injector data yet you seem to be the only one saying otherwise. Can it be tuned without the data....sure...but it's so much faster/easier with it.








