uwjberg

I'm troubleshooting my new swap and the bank 2 O2 sensor is reading .445V constantly so I'm chasing a wiring issue to determine why it's not working. Bank 1 is reading very lean at .015V. However, the exhaust smells very rich and like fuel. I'm new to the FI game but my understanding is that with that lean of a reading the PCM is probably calling for more fuel, which is why it smells so rich. I'm not sure I understand whey the O2 sensor would still read so lean in that case?

In any event, I'm just wanting to know if it's safe to run/drive while I troubleshoot the issue. If it's running super rich I would think it would be safe, although mileage would be bad and it will probably hesitate. But if it's running super lean I don't want to risk damage while I try to figure it out.

Hope this makes sense.

LS1Formulation

iTrader: (13)

An oxygen sensor reads oxygen content in your exhaust stream. The reason it smells rich is because your fuel isn't being burned, therefore the oxygen molecules are not being consumed. You are correct that the ECM is commanding more fuel, but it's merely exacerbating an already existing issue, not causing it. You have to do more diagnostics in order to figure out why the fuel isn't being burned.

uwjberg

Thanks for the reply. So I take it based on your response that you don't recommend driving until it's fixed? I thought I fixed a vacuum leak in the intake but I have to keep looking.
Appreciate the help.

uwjberg

I also should have mentioned that I don't have any codes related to a lean condition (any codes at all, actually).

LS1Formulation

iTrader: (13)

I would not drive it, no. You could be washing down your cylinder walls with fuel and ruining your engine. Diagnostics is a must. For example, the situation you're having could potentially be a fuel injector stuck closed, giving an artificial lean condition ( can't burn fuel that isn't there ), or a burned out coil ( if combustion doesn't start, the oxygen will remain ). Those are just two examples. Either way, the other cylinders on that bank will have fuel added by the ECM to compensate, and cause the unburned fuel smell you're experiencing.

uwjberg

Gotcha - thanks again. I checked for stuck open injectors and used a noid light but maybe it's a good idea to check if they are stuck closed too. They are new ones so hoping not but you never know.
Appreciate the help!

LilJayV10

iTrader: (39)

What vehicle are you working on? Truck, F body? Fork lift? /

Is it stock? Modded, if so, what are the mods?

uwjberg

Here is what I have - it's swapped into a 1966 Buick Skylark:

LM7 from a 2006 Silverado - cam and headers
4l60e from the same donor truck
Blue/Green PCM from the same truck - tuned by mailorder tuner to remove VATS, tune for the engine mods
PSI Conversion harness (HAR-1014)
the PSI C10 swap pedal ((ACC-1049) with pedal harness (HAR-1022)
New TAC purchased from PSI when I got the pedal
Corvette style filter/regulator - new with swap
255lph fuel pump - new with swap
New DW injectors

dw456post

Did the mail order tune include the correct data for the new DW Injectors?

uwjberg

As far as I know they changed the tune to suit. I provided the injector info including the flow data.
I don't have HP Tuner so I can't verify myself.
I'm beginning to wonder if i should get it just for diagnostics and being able to turn certain features on/off.

madmike90

Is this a new issue after it was already running correctly? Or was it present even at first startup when you finished the swap?

uwjberg

Update: I've swapped on a new intake manifold and got both O2 sensors working.
Both banks running lean and short term fuel trims are +26.6 in both banks, which to me suggests it's not an issue on one side or the other.
Here are the readings on the scanner once it got into closed loop:

STFT Bank 1 = 26.6
STFT Bank 2 = 26.6
O2 Bank 1 = .030
O2 Bank 2 = .045
MAF = 1.30 lb/min at idle
MAP = 18 (inHg)

When I start the car STFT is at zero but steadily climbs until it reaches the 26.
I've cleaned the MAF and triple checked for any leaks in the intake and haven't found anything.
Any suggestions for next steps?

uwjberg

I should also mention that I've replaced the PCV and all the vacuum lines.
I also tested the fuel pressure and it's rock steady at 58 at idle and with part throttle.

Full Power

.
YES.
You should obtain HPTuners Interface, and credits for your PCM

uwjberg

I had time for a couple of quick tests before dinner.
Did a smoke test and confirmed no leaks.
I also unplugged the MAF and got the following readings:

STFT Bank 1 = -16.4
STFT Bank 2 = -15.6
O2 Bank 1 = .805
O2 Bank 2 = .800
MAF = 0 (unplugged)
MAP = 17 (inHg)

I'm new to the LS game but those readings seem better? The negative STFT indicate the PCM is trying to lean things out right? Are these values too far in the negative?
Based on the O2 sensor readings it's seems much 'safer' than the very lean readings before to me.

Really getting stumped here on what can be causing this if I've ruled out unmetered air, unless it's the tune itself?

Kfxguy

iTrader: (1)

To the OP, you need to answer the question quoted above. Kind of important.

uwjberg

Sorry about that - got lost in the troubleshooting.
It's been acting the same way since I first fired up the swap, but there were some vacuum leaks in the intake I had to take care of after the first smoke test. I also had to fix the bank 2 O2 sensor.
I just wasn't sure if it was all related. I was actually disappointed to fix the vacuum leak and to still have the problem.