Swapped Injectors, Banish data, 165* stat SC ls1

[obzidian]

2001 ls1 corvette (stock longblock)
auto

Maggie, intake, mid-length headers, 165* t., 60lb. Siemens 107961 injectors.

Loaded the banish values, double checked and car is acting up.

The car is now smoking at idle. Also, LTFT are back up to 10%-15%. Before injectors they were around 2-4%.

Do I have to re dial in the fuel trims? Please take a look and let me if my data is correct.

[obzidian]

Update:

LTFT are raising to 15%+

Idles ok but breaks up under lite throttle.

[flame]

Your minimum and default inj pulse width tables should be .8 and transient min fuel mg .026

In a perfect world the inj data would not change your tune but yes you will need to fine tune it.

[obzidian]

Thanks. Are you referring to the min injector pw table? Also, the defaut inj. pulse table?

If so they are long tables ranging from 0 rpms to 8000 rpms. How do you here a single data value? Across the whole table?

I expected to fine tune the cal however the LTFT's are just crazy.

[obzidian]

Update: Tried the above changes.

LTFT's are still way high.

[obzidian]

Below is the last idle log I have of the car with the "new" injectors. They're Siemens "60lb" injectors part number 107961. They're rated at 60 @ 43.5psi. The car idles around 58psi.

So, at this point it is obvious that the engine is not getting enough fuel. If the LTFT data is correct that the computer is adding a ton of fuel to maintain stoich. (Last scan showed +25%) It may also be important that these injectors are NOT NEW and was purchased from a local who stepped up to a larger injector. They were never flown before being installed. Like i mentioned before, this is on a stock ls1 with a maggie (mp112). The previous owner was running E85 through them.

So as of right now, the LTFT's are just still high. The car smokes white, no fuel or oil smell. She starts up and idles ok. Whenever you give it a bit of throttle she beginnings to stumble and hesitate.

So is my data fine? If so could the injectors be at fault here? Anyways... appreciate the help guys.

[DSteck]

The data on Greg's CD isn't exact. You'll have to retune.

[flame]

Your injector data is correct so start tuning the VE and MAF tables. Since your trims are way positive you may want to add a bunch to the whole table to start. You are better to be pulling fuel out then running super lean. Your idle log shows an IAT of 167 deg which will amplify the lean condition.

[obzidian]

Dsteck: retune the injector data or ve/maf?

Flame: OK, I just didn't expect to be this far off. Seems like the trims were getting leaner and leaner the more the idled.

OK... I'll report back.

Just a heads up, I was using the SD tall data which is a frpp injector according to data. Is this correct for the 107961 injectors?

[DSteck]

Retune VE/MAF.

[obzidian]

OK... thanks. Ill start there then.

[obzidian]

So far so good.... the ve took about 30% to fall into line. Finishing up the maf low as we speak. Definitely not what I expect for a "simple" injector swap and data entry.

[Blingole]

I dont know if this is true but heres what ive gone threw lately. Ive always ran e85 and recently changed 80lb siemens out for 127's. The buyer for the 80's bought them ehh 20-30 days after the last i ran it then 3.5 months later sent them off to a injector flow clinic before he used them. They shown they all flowed 45-55lbs now, saying there was ethanol damage from sitting. I honestly think they just wanted him to buy 900 dollars in injectors form them, which he did.
Also i have a e85 cobra in my shop that has sat for 4 months (with a empty tank) and now that car is having injector issues also.


Just saying if you keep having fuel problems dont rule out a chance of the injector not flowing correctly.

[DSteck]

IDs are really the only plug and play option out there right now.

[Blingole]

^ i agree.

[obzidian]

Well.... made some progress today.

I got the car hooked up and started to work on the VE/MAf. Had a few hang up and delays as the car became to act irratic.

Anyways, like I mentioned it earlier, the VE table needed about 30% more in it to line up within +/- 3%. Next was the MAF. At first the logging and tuning process was going well until she started to get close to +/- 3% and even with the multiply % half option she was acting just weird.

I have the last few scans but I think the cars front O2's are going bad. After 2-3 minutes idling with the LTFT's close to 0% the O2's would stop to oscillate properly and get hung up. This would coincide with a felt stumble in the idle and the LTFT's shooting up or down 6-8% in either direction.

Anyways... seems like even if the injector data works fine for the 107961's siemen 60lb. injectors the cal needed some work to make it all work right. Overall I'm ok with how things turned out. This wasn't the first I swapped injectors and tuned for them however this is the first time I had to retune the airflow modeling to make them "work properly". Tomorrow I gotta meet up again and finish the WOT MAF stuff.... that looked even worst then the low throttle stuff!

Anyways... i'll upload the scans/bin's tomorrow... thanks for the help fellas.

[obzidian]

I dont know if this is true but heres what ive gone threw lately. Ive always ran e85 and recently changed 80lb siemens out for 127's. The buyer for the 80's bought them ehh 20-30 days after the last i ran it then 3.5 months later sent them off to a injector flow clinic before he used them. They shown they all flowed 45-55lbs now, saying there was ethanol damage from sitting. I honestly think they just wanted him to buy 900 dollars in injectors form them, which he did.
Also i have a e85 cobra in my shop that has sat for 4 months (with a empty tank) and now that car is having injector issues also.


Just saying if you keep having fuel problems dont rule out a chance of the injector not flowing correctly.

These injectors sat for a while as well. I thought that perhaps they needed to be cleaned and reflown thinking the e85 had damaged them. I've never seen a set of injectors fight back so much though the fix was more time consuming then anything else. I obviously don't have any proof of this but the thought did cross my mind.

FWIW the duty cycle on a few wot runs we did was around 50% at the top of 2nd and mid 3rd gear. 100% wot 11.6 afr. Its a stock ls1 with a maggie which was pushing over 90% with the 42lbs. green tops it had before.