I just ordered a set of Accel 30# fuel injectors to replace my bad set of factory 19#'s, I had 3 bad ones. I did this because I don't want to buy another bigger set when I run boost, the 30#'s will be perfect for that.

My question is, since I'm still very much a newbie at this, besides changing the injector flow rate from 19.76 to 29.45 (they flow 29.4 @43.5psi according to Accel), what else will I need to do right away to make my car run ok? I know it will take some tweaking in the VE tables to get it "just right", searching the boards here revealed that, but is there anything immediate I should change in the BIN at the same time I change the flow rate, you know for that same burn? I haven't gotten to the point where I changed the VE so I'm a little weary still. Also is there anybody here running Accel 30#'s on an LB9 and if so, what initial flow rate worked best for you or what rate would you suggest for me? I'm going to be using the stock FPR for now until I can buy an AFPR & guage so my pressure will be at stock 43.5psi and I plan on keeping it there.

I know I should just try it on my own and tweak from there however I'm VERY busy with work and this car is my daily driver so when I install my new injectors and burn the new BIN, I'm going to need something to get me by for as much as a week possibly before I could tweak it some more. I need to get a beater car for a backup bad I know

Thanks!

Alex

At a minimum set the injector constant to the proper value. This may need to be tweaked a slight amount to get 128 BLMs.

The crank routines use a PW scalar term. Until that is changed be aware of flooding problems on crank. Use a ratio of the old vs. new injector flow rate to adjust.

Other areas include the injector voltage compensation and the injector short PW compensation terms.

RBob.

So on the crank variable which of the 3 is the one I want to change:

Crank Fuel Delivery Delay vs. MAT
Crank Pulse Mult. Vs. Ref Pulses 1-24
Crank Pulse Width Vs. Temp.

And the other areas you said I would need to change are these right? :

Injector Pulse Width Correction Vs. Battery Voltage
Injector Pulse Width Low Offset Vs. Base Pulse Width

Am I on the right page so far?

Now I have to go beat my head against the wall for a while to learn what needs to be changed to what and to understand why and the math behind changing it.

Oh and the Injector Pulse Width Correction Vs. Battery Voltage should be fun because I have a low voltage problem I'm still trying to figure out and that's going to hurt the outcome of my tune adversely until I get that fixed, fun time lol!

And just to be clear, right now my engine doesn't need anything bigger than my stock 19#'ers, I'm simply trying to get 30# injectors "de-tuned" I guess you could say for my 305 so then when I add the boost, I'll bump them back up. Is there anybody here running 30# injectors who would be willing to share what they have changed the #'s to so that I can see what direction to go?

Crank PW scalar term:
RBob.

RBob, thanks for posting that however I can;t figure out where that term is in my bin using TunerPro and the Super_8D ecu definition file. I exported to a .txt and still can find nothing referring to anything about a max pulse width or a scalar term for a pulse witdh Can you please help me out?

Thanks!

If the parameter is not in the ECU file you can either add it in, or use a hex editor to modify the bin.

RBob.

Well being that I'm no where near the point of expertise on this stuff to go adding parameters I'll just leave it alone and see how it goes for now.

Thanks!

would you decrease the number with larger injectors?

I noticed that for a 305 (19lb) and a 350 (22 lb) injectors, the value in the bin is the same.

Yes.

RBob.

Ah... 305 with 19# and 350 with 22#, not 305 with 22#, hence the same value. If there were a calibration where a 305 had 22# the value would be less.

I have 305 with #21 ford injectors, I never changed this value.
( Maybe because of my cam/heads/ exhaust)

I have no problems with start up. Is there any other things that I might notice?

Ok this is still driving me nuts. I understand what I need to change and that a lower value is needed and why etc but the closest thing I can find in my AXXF bin using the Super_8D ecu file is the following with the below values:

Crank Pulse Mult. Vs. Ref Pulses 1-24

Ref. Pulse Mult.

24 0.20
23 0.20
22 0.20
21 0.20
20 0.20
19 0.20
18 0.20
17 0.20
16 0.25
15 0.25
14 0.25
13 0.25
12 0.25
11 0.25
10 0.25
9 0.25
8 0.25
7 0.25
6 0.25
5 0.25
4 0.25
3 0.25
2 1.00
1 1.00

What would you suggest I change it to for starters so I can tune from there. Remember I'm not going from 19# to 30# because I need them at this time so I need to get the 30# injectors "detuned" for my LB9 then when I run boost I put it back...

Thanks!

Going from 19#/hr to 21#/hr is less then a 10% increase in fuel.

Going from 19#/hr to 30#/hr is a 37% increase in fuel.

RBob.

Safe to say then that I lower all the numbers I posted above by 0.05 and tune from there?

I don't know about your low volatage problem, but mine was solved when I went to a one wire alternator......

I just went to 30# injectors myself (from 24's), Prominator due next week and then I get to run through what you are doing...... But at least mine will start off with a 350....

BTW, when's the next test and tune at Famoso????

http://www.famosoraceway.com/

looks like friday (tomorrow) at 6pm.
Maybe I should go - I've never been to a track.

Yeah I work so I can't be there

I have to preach tonight so I can't go either. I used to use the test and tune sessions to track improvements/declines from changes I made. I just haven't made any changes in a long time. Other than transmissions, rearend gears, and new pistons.... I hate parts breakage.... Hopefully the better converter and aluminum driveshaft will make up for the heavier pistons.