SSnakekiller

iTrader: (8)

I used the LS1Edit Fuel Injector Calculator to get my new values for my Delphi 50lb injectors. I am upgrading from stock injectors.

The values in the IFR table that the calculator came up with were about double what was in the table for stock which makes sense since the injector size is about doubled.

However, no matter what values I put into this table, the car will not run for very long. It sputters like it wants to stall. I even have a wideband hooked to the car which I have used before and works well. The wideband shows 20-25AFR!!! No matter what!!

I even tried loading the stock program which should make the car run rich as hell but no...

What is wrong here? Anyone?

SSnakekiller

iTrader: (8)

any1?

felton316

Did you change the IFR table the same percentage across the board or did you figure out a value for cell? Also, the 50# injectors, is that 50# at 43psi or at 58 psi. I know when I put in my 42# (42# at 58 psi), I just multiplied the entire IFR table by 150% and it was close enough to be able to drive and fine tune it.

SSnakekiller

iTrader: (8)

rated 90% DC 43-48psi 50lb

thats what it says, and they are advertised 50lb

I have done all ranged of ifr tuning and none work well at all. The closest was in the .4 area which is way off from the .6-.7 that the calculator suggests...

SSnakekiller

iTrader: (8)

BTW the Fuel Pressure is a consistent ~ 60psi Anyone else????
No matter what program I load it surges(for example if it had the hugest cam in the world) and then quits. Wideband shows avg 20-25AFR as previously stated

NoGo

iTrader: (2)

How to calculate your IFR.

Determine how the difference in pressure is going to influence your injectors rated delivery.

Adjustment = SQRT(Your pressure / Rated Pressure)
Adjustment = SQRT(60 psi / 43.5)
Adjustment = 1.1744

New Injector Flow = Old Injector Flow * Adjustment
New Injector Flow = 50 lb * 1.1744
New Injector Flow = 58.72 lb/hr

Converty Lb/hr to g/sec (like in your table).

G/sec = Lb/hr / 7.936
G/sec = 58.72 / 7.936
G/sec = 7.39 g/sec

Reduce this value by 3% for a safety buffer.

Safe Value = 7.39 * 0.97
Safe Value = 7.16 g/sec

Multiply your ENTIRE injector flow rate table until the first value (the one all the way on the left) matches this value.

If you still have problems after this, then you have other issues (is your injector offset table stock).......

-Kevin

SSnakekiller

iTrader: (8)

Thanks for the info..i'll try this.

btw I just did a flow rate test based on how the injector company told me to do it. It checks to see how much volume of fuel you are flowing. I did this to make sure I was getting enough fuel bc of my lean cond.

Here is how it is done.

Go from fuel rail or return line and activate fuel pump for a period of time into a suitable container.

Steps:
1. Weigh container
2. Run fuel into container for a certain time.
3. Take the weight of the fuel after step 2 and multiply by the amnt of seconds you ran your pump for.
4. Multiply that by 2.

The result is approx how much HP you are good for with that fuel setup.

Ex:
Run pump into container for 1 minute.
Get 7.5lb of fuel
(7.5X60)X2 = 900

Should be safe for approx 900FWHP
-----------------------------------

ANyway, if I cant get it tuned I might send these POS back and get 42s or I have heard good about the 60lb

SSnakekiller

iTrader: (8)

Oh yeah offset has been stock through most of my tests but I got a table from someone else with 50lb injectors that had to change the offset, but when I changed it, it did not run very well...

SSnakekiller

iTrader: (8)

Nope, when I scale it so the first value is 7.16 the car fires and thats all she wrote...
I scale it down 5%, same thing. DOwn 5% more and same thing...

Best I got it to run was in the 4's somewhere with the offset table changed...but it still doesnt idle well..Im sick of dealing with these, i might change injector to 42...

red ws6 99

I am using around 7.16 in my injector flow rate table on the msd 50 lb with the offset table I sent you. So the delphi's are probably a different design. If you are having to put the ifr table down in the 4 range, you probably have a bad o2 sensor or vacuum leak. Check that stuff first.

Gary

SSnakekiller

iTrader: (8)

Well, I put my stock inj back in and the car runs perfect! Boost guage shows steady -20 when idling so would that indicate that I do not have a vac leak or is that not a good way to test?

I am sending these POS back and I ordered the 60# Mototron that everyone is having good results with...I hope they work well.