Need Tuning Help Rich or Lean No In Between

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.

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???

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

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?

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

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.

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Originally Posted by 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.

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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.

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.

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

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.

It is in open loop SD so the maf is not factored in. I have checked for vacuum leaks but have not found one yet. Might bring the smoke machine home from work tomorrow to check it. At this point I am almost ready to trailer it to a good performance shop. I know that is said coming from a L1 certified ASE mechanic who is also a Toyota Master Diagnostics Technician. But I am stumped at this point and am out of ideas. 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.

By the way I have learned more about HPT in the last week trying to fix my truck. Than I have in last two years of tuning about twenty vehicles around town where I live.

Something like this is hard to track down if you have checked all the basics. If ur near us bring it by. We can troubleshoot anything.

if it was fine prior then all of sudden is jacked up then i would do the following

check harness for any possiblity of harness issues....aka rodent chew marks, burned wires, shorted wires, broken wires

in OLSD you should be able to do anything you want with the tune with no interference of any sort from the pcm

o btw LC1s are junk!!! i wouldnt trust them for my life. ive seen to many fail and my old one personally was a full point off

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Originally Posted by farmtruc

Something like this is hard to track down if you have checked all the basics. If ur near us bring it by. We can troubleshoot anything.

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I think it is going to be something wiring related. If I was close to you I would definitely bring it by. However, I am in Paris, Texas. It is a little over a 7hr drive/tow in this case.

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Originally Posted by Quik

if it was fine prior then all of sudden is jacked up then i would do the following

check harness for any possiblity of harness issues....aka rodent chew marks, burned wires, shorted wires, broken wires

in OLSD you should be able to do anything you want with the tune with no interference of any sort from the pcm

o btw LC1s are junk!!! i wouldnt trust them for my life. ive seen to many fail and my old one personally was a full point off

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My LC1 has only had a couple issues before that were calibration related. It and my O2's have always agreed on Stoich or Lambada. However, I have read some about them having a lot of issues.

I had some wires messed up near the IAT. That I posted about a couple weeks ago however that is the only place I have found damage. I work every day as a master tech and am now being humbled by this. It has been a week now that I have worked on it every day after my day job. Still have only checked off what is not wrong. Probably going to be something really weird but simple when I find it.

Ok an update is in order. Still not fixed but have some more information. Smoke tested the the intake and it is all sealed up so no vacuum leaks. However, while messing with fueling in RTT. My buddy (Also a Toyota MDT) noticed that at a certain point bank 2 would go lean a little bit before bank 1 switched lean. So we went the other way with it and bank 1 went rich before bank 2 did. The reason for not noticing this before now is my wideband only is on bank 1. We swapped sides with the O2's to see if it was the sensors. The problem stayed on the same banks so that ruled out the sensors. Going to swap injectors from Bank1-Bank2. See if problem moves banks. Starting to lean toward a leaking/no closing injector or a stopped up one. Depending on bank.

Any input on this would be taken constructively.

Okay, swapped injectors bank1 to bank2 and the one bank lean one bank rich moved banks. Think it was a injector problem after this. I ordered new injectors form Jon at FIC. Installed them with known good data and flow rate. Still can not get the truck to run at 14.7. Both banks a nearly exactly even now on AFR but the engine is at 7.4 or 20.1. The O2's confirm full rich or full lean. If I change the VE table more than a couple numbers in a cell (Example: 51-52) it goes rich. If change to 51 it goes lean in that cell. Please help. I am getting desperate and tired of messing with this thing. The new injectors were not cheap and funds are getting tight.

Link To Current Tune

Current Tune

whats the ign. timing doing when your data logging? (i don't have hp tuners so i cant see your tune). have you tried a different ecu?

I have not tried a different ecu due to not having on handy and don't wont to waste HPT credits. However, I am about to be ready to try a new/different ecu. The timing is normal/where I set it, 22° at idle and stock 5.3 timing after that. Have not been able to tune the timing tables yet.

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Originally Posted by country_3030

I have not tried a different ecu due to not having on handy and don't wont to waste HPT credits. However, I am about to be ready to try a new/different ecu. The timing is normal/where I set it, 22° at idle and stock 5.3 timing after that. Have not been able to tune the timing tables yet.

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As I was reading through this, my first thought was ECU and/or wiring issues. The fact that changing it just one number higher/lower causes such wild swings sounds like a computer problem to me. The only other thing I can think of is that possibly there is a decimal place error, but Im not at all familiar with HPT so I dont know if thats even possible.

I will get with nelson and see what he would charge me for an ecu.

I don't know why you are even messing with the tune. You know it is a mechanical issue.

I know it is a mechanical issue or electrical. However, every time I post anywhere else I always get asked for a copy of the tune. Figured I would go ahead offer it to get that out of the way. Today I am going to check the computer ground at the computer instead of the engine where it grounds. Then going to solder a couple of the injector connectors. So far I have fixed 30 minor little things and am still going. Once I figure out what is causing this it should run great and have no problems.

Okay. Looking back, it may have sounded like I was being a dick. I didn't mean to come off that way, just thought we had established a mechanical problem and was wondering why the tune was even being touched.

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Originally Posted by pl4yboy

Okay. Looking back, it may have sounded like I was being a dick. I didn't mean to come off that way, just thought we had established a mechanical problem and was wondering why the tune was even being touched.

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No I didn't think anything of it. Just posted the tune for reference. Any clue what could cause this?

After replacing the injectors and using correct data the truck was still not fixed. A lot of testing and ohming later I decided to try a new pcm. Copy and pasted my tune into the new pcm and everything is great now.

I know, I know, late to the party. So after all that it turned out to be a bad pcm? I wondered if it was a fuel rail issue, but looks like you're good to go. :thumb:

Yep, PCM fixed it. Ran great for about 200 more miles. Then spun some bearings. I think all the detonation from the bad pcm helped it break the oil film and spin the bearings.

Sux man but at least you got the problem figured out