Am I out of injector?

[turbopete]

02's and tune were great with the stock engine and a 49 turbo. MSD 50's were recently flowed.

After the rebuild, I have a 6157 with cleaned up heads, 194/204 cam, a new fuel pump and alky.
Went tuning today and see that I am having trouble getting the 02's at WOT to stay up where they belong. Scanmaster recall had 680 at 96 MPH. No knock. This was with fueling in the chip +10%.
Changed chip fuel to add 20% and the 02 recall at WOT was up to 730. Obviously, the change made a difference, but not enough.

I understand that with 20% fuel added, it has the injectors at 95% duty cycle.

So, either...

1. I have added so much fuel that the car is finally pig rich and I just haven't realized it
2. I have run out of injector trying to get the 02's up to 780-810

And, BTW, the car feels laggy.

Thanks for the input.

 

[Steve V]

See my emails

In short, NO....:tongue:

 

[WSLN 6]

Wideband would be the only thing to trust in your situation. Wouldn't hurt to check fuel pressure at WOT as well to rule that out. Even without alky you should not be running out of fuel with that turbo and 50's IMO.

 

[SCOOBY DOO]

50's and alky are more than sufficient for that turbo.

 

[turbopete]

Thanks

Back to the drawing board...

 

[bison]

What boost level was the chipped burned for? Was this for use with alky? Chances are you need a re-burn

 

[Ttype6]

Back to the drawing board...

What is your static fuel pressure with line off?
What boost are you running?
What is your fuel pressure at that boost level?
What brand fuel filter?

 

[turbopete]

I have the plan

It says "go read the directions".

Thanks for the input. I really appreciate it.

 

[bison]

I understand that with 20% fuel added, it has the injectors at 95% duty cycle.

How did you determine this? This is not likely with stock headed application and injectors that size if Eric burned your chip. 20% added means 20% more pulse width. Not 20% more duty cycle since DC is just calculated based off pulse width and the engine speed.
Here is an example of the possible huge difference between 2 chips both burned for the same injectors (50lb/hr):

RPM PW ms DC lb/hr
3600 17.2 52% 25.8
4000 16.7 56% 27.8
4400 16.4 60% 30.2
4800 16.2 65% 32.4
5200 15.2 66% 33.0
5600 14.3 67% 33.3
6000 14.3 71% 35.6
6400 14.0 75% 37.4

RPM PW ms DC lb/hr
3600 21.1 63% 31.6
4000 21.1 70% 35.1
4400 21.6 79% 39.6
4800 21.8 87% 43.6
5200 21.8 95% 47.3
5600 21.6 >100% 50.0
6000 20.8 >100% 50.0
6400 20.4 >100% 50.0

Notice at 5200rpm one chip has over 40% more fueling than the other. Even if you maxxed the adjustment out on the first one you wouldnt even be close to having enough fuel for the combo in the 2nd chip at its baseline settings. Ive seen a lot of lean cars because of oversights like this.

 

[Steve V]

I am not gonna call out specific chip burners cause they are both great. But here's my input. I built the car and set it up last Jan. It has had some mild work in the heads. And all of the above parts i post #1,when it left my possesion it ran like a raped ape. Then Pete changed to a different MFG's chip to get rid of some minor driveablity issues.

The car ran fine but O2's have never been the same. Then the parts swapping began...new o2(delco-new version not OEM),new fuel filter,new pump,testing the alky system. No problems found anywhere.

My solution...install orginal chip and see if o2 return to normal. OP has not done this and seems convinced to work it out with the current chip. That's how I would eliminate the chip issue.

Even when his 0 2's are 680 ish with 43psi base,alky on 6,boost 21-23 there's no hint of any knock on the scanmaster or powerlogger. Isn't it possible the stock o2 is not the best way to guage the tune.

And lastly...cas v4,6152,stock headers,194/204 cam....all out the stock downpipe.

See ya

 

[Otto J]

If the chip was burned for the 49 turbo it will need a reasonable increase in fuel trim to be good.
May be a good idea to send chip back for a reburn,or add more alky

 

[turbopete]

Late night frustrated postings without any sleep

Please forgive my posting on the inability to tune my car. I drive it around, look at a number, get frustrated, and this is the result.

I am going to turn it down and go back to square one. As has been mentioned, the NB 02 sensor is not the right tool to get even a rough tune any more. When I changed sensors, it obviously has some kind of different calibration and the numbers just are different. I will see if the other chip changes things. I doubt it because the chip will see the same sensor data. I can change back to the other 02 sensor, too.

I am going to the tb.com nationals and get some help installing a WB 02. I have changed my mind on this several times (I am allowed to do that...) It is the right choice to properly tune.

Then, who knows? I might choose to not post my progress next time.

 

[WSLN 6]

Always post your findings, lots of people on the board are just waiting to see if they can help in any way. This is a very limited group of people and frustration usually runs deep. I have spent more time on my car in the last decade than anyone ever should. PM me if you wish, always looking to save someone a step and some monies....

 

[bison]

I doubt it because the chip will see the same sensor data

Unless you have wideband correction then the correction will only happen based off the MAF. Once that is maxed out it reads directly of the fuel map ignoring the maxed out MAF number.

 

[Steve V]

TT chip uses maf lock past a certain value. Not sure if that's doubled on the extendar chip since the ability to read the maf table is doubled. Does it also lock and at what point. Not sure if this combo will max out the 512gps it can read,but it will max out the 255gps the TT chip reads.

I will reiterate again this problem did not manifest itself until TT was put in the ECM. With the extandar o2 were good. And both chips are burnt for alky with the current 6157 set up he's not using an older 49 chip here.