what do you need to change in the injector tables in order for these suckers to run properly?

 

here we go again with injector questions and no respones.......................................... ......................... does anyone know how to do this stuff I mean i know people have swapped the stock ones and a lot of people have gone with these motron injectors.....

 

Do you have editing software? HPT edit EFI ?

 

efi live...see signature..

i know about changing the IFR table, thats done. and i now changed the min injector pulse width according to SMOKINV8, which he is right on that, but what else do i need to change?

 

You need to go out and street tune it. Mine starts up great with them. I just installed them Saturday. Just started adjusting via the main VE table. I didnt however mess with the injector pulse width

 

are you running SD OL tune?(speed density Open loop?)

 

Yes

 

then that does not apply to me. The spreadsheet that RedHardSupra gave all of us does not quite cut it all.... i called Nick Williams and you don't have to change anything else except for the IFR, it just takes some tweaking; there are also other ways to skin the cat but this is the easier

 

nevrmind on the Ve table.. i'm still going to have to re-tune it

the IFR calculator is wrong though.
anyone willing to help with what worked for them on the motron 60#ers on a NON SD OL car?

 

so what else needs to be done? how is the IFR calculator wrong?

 

it might not be completely wrong...just some values are off.
when i work it out i'll let ya know.

also, i installed these and if you can figure it out i would greatly appreciate it if you could help me.

the injector pulse width voltage adjustment... do i need to change this any, as these 60s are a lot bigger than the stock 28.8s?
the IFR..I went exactly off of the excel sheet....since at idle my pressure is 60 should I use 58 or 59 and put in the 60# injectors and give it a go?
what other tables do i need to change?

right now the car when I let off the throttle and slow down, then get back on the throttle it wants to jolt back and forth for a second and then it catches itself...whats up with that, is that the injector pulse width voltage adjustment?

 

The injector spreadsheet that RHS contributed to the forum has what I would call 97% accuracy, it really is pretty close. I swapped from SVO 30's to SVO 39's and went off his spreadsheet, and the results were pretty close. It took a little retweaking, but everything was still very close. I then backed my fuel pressure down to 50psi, and once again, everything was very close. By very close, I mean my fuel trims swung less than +/-5 in any given range. If you do some searching you'll see that there's a number of people who have had trouble with the Motron 60's, but the reasoning isn't clear.

Keep this in mind though. Even if the IFR isn't exactly right, your fueling is still subject to incorrect fueling from the VE and/or MAF calibrations. But you will need to reduce the minimum injector pulse so the car can provide close fueling at idle and decel.

 

I didn't change my injector pulse when I put mine on. Would this help my idle if I did this? How much should it be changed?

 

right now the car when I let off the throttle and slow down, then get back on the throttle it wants to jolt back and forth for a second and then it catches itself...whats up with that, is that the injector pulse width voltage adjustment?

 

Forgive me, I'm not sure who Nick Williams is, but to do it properly you need to work on the injector offset table also. The VE table has nothing at all to do with injector changes.

Good luck, Ed

 

I think you misunderstood what I was saying, or maybe I'm misunderstanding you. The fueling determined by the VE and/or MAF is independant of the IFR, but since all three can play a factor in fueling, they're also related. If the VE or MAF wasn't perfect before, they won't be perfect after (your IFR change), and finding the correct IFR may not be very easy either.

 

i caught myself when i started thinking about it. I do need to dial it in.....only sad thing is i will need to do it again when i get the turbo installed in august

but it doesn't take long to get it within 5% of what i need. so i'm changing the VE table(dialing it in again) and I got the IFR set to what the excel sheet has, and I changed the injector offset (injector pulse width voltage in efi live) by -30% b/c of the such bigger injectors

also when i was running the car earlier the fuel trims were at -10 and -12.5%....gonna see how that changes now

going to go in this damn hot weather in wilson,nc and dial that thing in now.....with these bigger injectors will my VE table will decrease?? cuz it looks that way??

 

that's why it's super important to be scientific about it. one change at the time. start with things that are calculatable (IFR) and stick to them, as you know that supposed to be the truth. VE we can't calculate, so we just approximate it empirically. if this approximation is pretty good, changing injectors should NOT change our fuel trims. of course, that's theory. in practice, you never know _exactly_ how much the injectors flow, there's variances between injectors, fuel pressure might drop unproportionally due to slowly dying fuel pump, etc...
so while the calculated IFR isn't perfect, it's a good 'constant' to have.
if we treat it sas a constant, and tweak VE to make up for all the imperfections, one might ask how is VE tweaking different from IFR tweaking? aren't we 'lying' afterall, and pick what's a constant and what's not?
my answer to that is that yes, unless we can have all the data 100% dead on, we are technically bullshitting. The reason why I like to treat IFR as constant and VE as my 'variable' is the nature of these two:
IFR can be nailed pretty damn close. fuel pressure can be measurable. injectors can be flowed, data can be crunched, and it doesn't change much on day-to-day basis.
VE is very different. there's temperatures, humidity, and pressures involved. that changes hourly. so why not use that inherent weakness and turn it into something that works for us--a quick place to accomodate changes.

another big reason is resolution: IFR depends on fuel rail pressure. nothing else goes off that in the engine. VE goes from rpm and MAP sensor data. just about every other calculation goes off that. not only that, but these two allow us to describe a lot of different conditions in the engine. we can distinguish between same pressures at 2000 and 6000rpms, while if we go purely off fuel rail pressure (which is closely related to MAP) then we cannot. thus, adjusting VE is much more fine grained, and gives us a more powerful mechanism to accomodate all the changes or imprecisions we're trying to compensate for.

 

I will agree 100% with this statement.

 

you should Chad, you taught me a lot of this stuff a long long time ago