Bobsmyuncle

iTrader: (32)

well ive checked, re-checked and checked agian. the values are all fine. with all of the injector values in, car will crank and fire and instantly shutoff. i can pedal it, but i can hold it to the floor and no throttle response.

now, i wel in and took the ifr table down in the 60s and the car starts and runs........?????

ive looked everywhere i can, and i cant find anything.

NicD

iTrader: (7)

Without posting the tune it's pissing in the wind.

Bobsmyuncle

iTrader: (32)

done!!!

NicD

iTrader: (7)

A few details on your setup? First glance I see your transient minimum fuel pulsewidth hasn't been changed and you have a huge drop off between 12.5 and 13.0 in the voltage offsets which isn't normal.

Bobsmyuncle

iTrader: (32)

5.3/gt4788/th400

i thought the offsets were fishy too, but thts wht the chart they sent me looks like. i will double check now

Bobsmyuncle

iTrader: (32)

yea, data they sent me takes a dive from 12.5-13v

wonder if the data is junk??

turbolx

Perhaps. Running a complete characterization takes a fair amount of effort, and sometimes people don't like the results. Check out this article I wrote after testing some testing a few different types of high flow injectors.

NicD

iTrader: (7)

That doesn't look like the data I had for those injectors, wonder if they sent you the right stuff. Either way, you are running a turbo speed density setup with a 1 bar OS? What map sensor are you running and you realize that you can't be boosted on a 1 bar operating system right? Even if the data was off it's not going to do what it's doing, it should at least start and idle and cutting the flow rate in half to get it to idle tells me you have another problem.

Bobsmyuncle

iTrader: (32)

I realize it's 1bar, I bought a 3bar off here and it was dead on arrival

white01ss

iTrader: (37)

Some things to try...

Fix your voltage offset table

Raise your idle speed until it will run on it's own.

Fatten up your VE table in those idle ranges.

Raise you minimum pulse width. If your injector pulse with isn't long enough the injectors won't even open.

I've seen engines so rich that the gauge won't read it but, they still run. It's when it's lean that the engine wants to die. Fatten it up! Good luck.

Bobsmyuncle

iTrader: (32)

Do u think the offsets will make that much of a difference? The difference between the before and after was like almost a full point or more, before I think it was .089373 to 1.3 or somethin

Bobsmyuncle

iTrader: (32)

Minimum pulse Is set at FIC Recommended value.
I see what u are saying, but when I take the ifr to like 60range, the car idles perfect. Pulswidth hardly even moves. And it's still wicked lean bc the fuel trims creep up and up then max

Bobsmyuncle

iTrader: (32)

So is there any multipliers for the ifr table that could be cutting it in half?

I wouldn't think the offset would do it, but since this is just at idle, it might make a big difference bc the injectors are only active for such a short time

Bobsmyuncle

iTrader: (32)

Good eye nicD, swapped the offsets out fr IDI1000 offsets, and it runs with the ifr table at 114

C6Roadracer

You can't just swap and adjust injector data. The is the data of that injector and it tells the PCM what the injector does not the other way around. You need a injector that has proper data to start with. No work arounds.

edcmat-l1

iTrader: (10)

And therein lies the problem........

white01ss

iTrader: (37)

As said before, get your IFR and offsets to the correct values then leave them alone. The PCM needs those values to correctly model the injectors.

If you have a different cam it may have pushed your idle into a different area of VE table causing the lean condition. Calibrate your MAF and VE tables to adjust fueling, not IFR/Offset

BTW, offsets make a HUGE difference at idle and light throttle. I understand you may not have good values. Start with offsets from what the injectors originally were then add 10-30%.

Also, I wouldn't run closed loop unless your O2s are very close the heads like stock exhaust manifolds. Also, you may have to adjust O2 switchpoints to keep them from jacking up your fueling. My advice is get things running in open loop first, then add the O2s back in if you wish.

turbolx

This is absolutely correct. You MUST know the injector characteristics before jumping into airflow and idle tuning, not the other way around.

Although someone may have told you this, it's not necessarily true or even in the right direction. The simple fact is that modifying an injector often moves the offset by more than it moved the slope (flow rate), often resulting in negative values that can't even be plugged in to a late model GM PCM. Take a look at this article I wrote recently and see the results first hand.

white01ss

iTrader: (37)

Excellent article. I've read both your books as well. I believe I understand the gist of the article about the tuning difficulties inherent to some of the re-drilled injectors and especially with the unpredictability at low pulse widths.

To get these injectors to work requires some starting point for the offset data. I was pulling said starting point out of my you know what, but not having the access to that data you have to start somewhere. Will it be perfect? No, but sometimes folks just have to get what they have to work the best it can.