Need Tuning Help Rich or Lean No In Between

[country_3030]

I recently finished building a iron ls1 for my truck. It has 42# Delphi Injectors, Comp Cam 219/227, 11:1 Compression, DCR is around 8.75:1. After start up it ran okay and once I began tuning it ran great till about 4000rpm. Which is as far as I got in rpms before it started acting up. Now after about 200 miles it is either really rich or really lean from idle till 4000rpm. No matter where I set the VE add or subtract it goes the other direction (Rich or Lean). Both my wideband and my O2's agree on this (7.4 or 20.1). When I turn on fuel trims it switches really fast between the two. It just can't find a middle ground to run. I am stumped because it ran great for 200mi then this. Please, help it is my DD. Have had to drive my mud truck lately and no a/c is not my favorite in Texas heat. Thank You, in advance

Since I can't post a tune here I will link the thread I started on HP Tuners Forum.
HPT Thread

Let me make a list of what I have checked and tried.

1. All grounds are good: PCM, Battery to engine and body, both on back of the motor, and the one by the power steering pump.
2. Fuel pressure is 53psi with vacuum and 60psi without.
3. Have tried every combination of injector data from HPT Repository that has 42lb to 60lb injectors. Seriously I have flashed my truck over 100 times. Ran fine on previous data till I parked it for several hours.
4. New O2's went in with the motor 200mi and 2 weeks ago.
5. All injectors and coils are firing checked by way of cylinder drop test.
6. All input sensors are giving the HPT Scanner good readings.
7. Not a vacuum leak, smoked the intake system.
8. Not the injectors installed new ones from FIC with correct data.

[country_3030]

Okay, got the truck where it switches back and forth between full lean and rich. This is in open loop SD not closed loop. Not sure as to what is going on. Any ideas???

[farmtruc]

Are the o2's ok. How did you verify them?

[country_3030]

O2's are new denso units with 200mi on them and I have a LC-1 that I used to verify. When the O2's max out rich or lean the LC-1 is also at 7.4 or 20.1. The guys on the HP Tuners board seem to think that my injector data is wrong. They are injectors from a TVS 1900 kit. The same ones TurboMic had in his tvs1900 tune. I think you tuned it for him. Could you maybe share the injector data with me?

[farmtruc]

just stick with the basics, just put in the correct idc table, start there.

[country_3030]

IDC? I am not familiar with an the idc table. I have the IFR table set and had the truck running great for 200mi. Then parked it on day. Later the same day got in it and the AFR was swinging rich-lean-rich. Have had the problem since. This is in open loop SD when it is swinging rich-lean.

[pl4yboy]

IDC? I am not familiar with an the idc table. I have the IFR table set and had the truck running great for 200mi. Then parked it on day. Later the same day got in it and the AFR was swinging rich-lean-rich. Have had the problem since. This is in open loop SD when it is swinging rich-lean.

IDC is injector duty cycle.

If it were me, I would put in stock injector values and scale them for the current injectors. There are write ups on HPT on how to do it.

[country_3030]

I know IDC is injector duty cycle but I have never seen a table for it in HPT. It is a measurement as far as I know and not a part of the tune. Not to knock any one on the HPT forum but I still don't think this is an injector problem. Since it started after the truck had been parked for several hours. There was no changes made to the truck between the time it was parked and it started this.

[RedHeartbeat]

clean the maf and if that doesn't do it check for vacuum leaks.

[Frenchy]

Vaccum leak somewhere? Like you said it was fine for 200 miles. To me that's not tune related, it's not got a Quadrajet on it, it can't fall out of tune.