pwrtrip75

iTrader: (8)

Im using HP tuners. I put 160 lbs/hr high imp injectors in my car and I changed the injector flow rate and now the rpms go up and down and wont idle. Even when i give it gas and bring the rpms up to about 1500, they still go up and down like crazy.

I tried messing with the idle air flow table, no results. Is there something else you need to adjust in 100 different injector tables when adding ones this big?

Rundown of the setup
370ci. 9.8:1 compression TU1 cam.
E85
Turbo - truck manifolds to a PT76GTS
Billet Atomizer 160# High Imp injectors.
40-42psi base fuel pressure.

This same tune I used on 2 different other engines similar and ran awesome. It was last used on my stock 6.0 w/ LS6 cam and 60# injectors.
I still have to hook my WB up to it and dial it in, but it wont even stay running. This tune should at least keep it running.... unless theres more to adding bigger injectors.??

Thanks.,

macca_779

It's a very big injector. Probably can't get a small enough pulse. It's running rich is why its hunting.

pwrtrip75

iTrader: (8)

....but it should be able to idle.

macca_779

What makes you so sure.

2xLS3

iTrader: (3)

Whats the injector pulse width at idle?
Is it below the mininium pulse width the injector can run?
I realize you're running E85, but that still seems to be an oversized injector

pwrtrip75

iTrader: (8)

Because other people can do it.


no idea. how do you know what the minimum is? I have not messed with any other table than the injector flow rate.

2xLS3

iTrader: (3)

You ask the injector manufactor for that number
They only list the low impedance injectors on their website
its listed as low 1.2 milisecond, you'd have to call them and see if that also applies to the high impedance ones. You should log your vehicle and see what its trying to run them at. Running them at near their mininium, isn't going to let them be very stable

pwrtrip75

iTrader: (8)

I sent him a message.

Thanks.

pwrtrip75

iTrader: (8)

well havnt heard back yet. But I got it so when you start the car it idles perfect... for 10 seconds.. then it starts going up and down again. When I first start the car and its fine the injectors are at 3.0ms, then in 10 seconds it fluctuates from 2.0-3.4ms and has a hard time staying running, smokes out the exhaust and after about 30-45 seconds it dies. and smoke continues to come out the exhaust.

2xLS3

iTrader: (3)

What are the IAC steps doing, when the idle dances around?
If the IAC setting is dancing around
Start the scanner and go in to VCM controls
Click on the Special tab
Maneally set the IAC steps at a fixxed value
See if helps

pwrtrip75

iTrader: (8)

Not sure how to see what the IAC steps are doing. I gave up for the day.
Im thinking my base fuel pressure is too high. With the car off its 40. and when running its up to 50psi... my gauge bounces around so its hard to see... but i think too high. The aeromotive regulator is down all the way and still cant get the pressure down.

Old Geezer

iTrader: (3)

"The aeromotive regulator is down all the way and still cant get the pressure down."


How is the fpr plumbed into the system??

ctd

iTrader: (1)

In the Transient Table, check your "Min Fuel Milligrams". If that is to high your pulse width will not go low enough.

Scan your injector pulse width, if that will not move as you try to lean down the idle area it maybe the problem.

pwrtrip75

iTrader: (8)

I have a -8 line feeding each rail from the rear, then the FPR is mounted on front and returns through the stock feed line.




I just heard back. the minimum pulse width on these injectors is mid 2.0ms. I lowered that min fuel mg table to .020 from .045 and got the PW down to 1.9 it idles smooth for like 5 seconds then dies.

It sucks because i dont do this every day so everytime i pick up the laptop and start in on a project I have to relearn HP Tuners. The number values always screws me up in the airflow tables... like the idle air flow.. what does the numerical value of the number mean and increasing that does it give it more fuel or less? Ive fluctuated this number 15 each way and been messing with this car to get it running for about 10+ hours combined this weekend.

Right now it starts, idles fine for 5-8 seconds and then dies. If I pump the gas pedal up and down really fast it stays running a little, but if I slowly press it just fall flat and dies.

pwrtrip75

iTrader: (8)

ok... I added like 25% to my VE table.. it runs, tachs up now and seems normal... except after idle. When you first start it, it idles at 700 and then slowly goes up to about 1000 where I have it set, it idles perfect for 15-20 seconds and then slowly starts going into its up and down fit. The idle then goes up and down for 10 seconds untill the car finally dies.

What is the the car doing after 20 seconds of initial start up? Does it go off of some other table? How can it run so good, and then just go into a phase after 15-20- seconds?

pwrtrip75

iTrader: (8)

Dropped the timing down to 6 degrees at idle. Seems to idle like a champ Now oil pouring out the exhaust side of the turbo... yippy!

2xLS3

iTrader: (3)

How can you return the fuel through the stock feed line, it has paressure in it, if you're also using it as the supply line unless I don't understand what you're doing. Did you run a new fuel line to supply the regulator and just reuse the original line for the return?

pwrtrip75

iTrader: (8)

It has a -10 supply line and the old feedline is used as a return.

pwrtrip75

iTrader: (8)

Another thing it could be is I had my oil drain line hanging too low, oil was blowing through the turbo seals and leaking out the exaust. If its in the cold side piping too that oil burning could affect the idle. I'll look tonight.. what a PITA. lol.

2xLS3

iTrader: (3)

OK, that makes sense I though you tied the line back to the supply line