Hey guys, my fuel trims are saying I'm really lean, car smells really rich, I've checked for vacuum leaks, I've found none, I've check for exhaust leaks, I've found none, I do have the P0133 & P0153 codes, I have new front Delco O2's, rear deleted, also have new Delco MAF, Car has LS6 heads an Intake, F14 cam, Lt's, it's a M6, besides the tune is there any thing els I should be checking??

 

smells rich, can't go by that, especially if you have NO cats. If the trims are positive like that, can the tuner take a look and see? what is your idle MAP?

can you post the tune? or a scan log of the car?

 

IS it one bank or both?? It both probably just needs to dial in the fuel trims via MAF (if your not SD) if just one bank you have a problem.

 

Both banks,
MAF 8g/s
Inj PWM Avg B1 3.5 msec
Inj PWM Avg B2 3.5 msec
Rpm 850
BLM CELL 20cnt
Barometric Press 30 inHg
MAP 17 inHg
MAP VOLTS 1.1
Intake temp 158F
Coolant temp 189F
ST fuel trim B1 21.1
ST fuel trim B2 24.0
Spark adv 22 deg

 

Both o2's switch really slow staying on the lean side longer dropping as low as 95 then slowly working its way up to about 850 then go back down quickly.

 

The sensors are probably just too cold at low gas flows.

 

Unplug your maf as long as it doesn't have the built in iat sensor and see if your fuel trims come back to normal. If they do you either have a bad maf or air getting in behind the maf.
If they don't come back verify your fuel pressure is good. If it is have your tune checked.

 

I checked fuel pressure an it holds steady at 60psi, I let it warm up idling , fuel trims were about +18 to +23, I then unplug the MAF and the trims went to -33 to -37, Tune??

 

The MAF that was on the car when I bought it was an all aluminum unit that looks factory but has no screen or divider in the middle, I was told that it was the problem, the new one I have is a newer plastic style Delco with the adapter wire on it, could this be the problem??

 

Intake temp 158???
MAP 17?

Those two seem kinda screwy to me.

 

Intake temp does seem high, but the MAP seems normal for idle...just shows the engine has ~13 kPa vacuum unless I am incorrect or missing something.

 

17kPa is mighty low idle MAP for any car. I recall 30s when
stock, it's well higher now on mine.

 

I guess I'm just confused this morning. Isn't 28-30 usually ambient air?

EDIT: just realized difference in units of measure, he mentioned inHg rather than kPa

 

yeh, 57.6kpa. get tuner to look at it, something is not correct.

 

OK. I don't find 50kPa-range unusual for anything with a
cam and a blower dragging.

A rich smell is likely high HC, which can come from either
rich or lean. The difference is, lean will sting (NOx) and
rich won't.

I'm still suspecting false trimming. Especially if it idles nice
after you reset the trims, and then it goes to crap over
a minute or two of sitting at idle. Do what you can to
check that. Try turning off LTFTs and let STFTs do the
work, because they reset on every cell transition; high-
idle it to get the sensors hot, then drop to regular idle
and see how the STFTs creep, whether they are happy
for a bit and then head north as the pipes cool.

 

i beve the LT FT are turned off already, they never moved off zero, i just tried warming it up, kept rpm's up high and reset ST FT to zero, they started creeping up immediately while still at high idle, i guess next is back to the tuner.

 

You either have a bad maf or vacuum leak. If it were in the tune then your maf table is seriously messed up but I'd suspect one of the mechanical issues I just mentioned.

 

My MAP reads in the 50 range at idle. It targets the fuel cells in the VE table for fueling so its pretty dang important.

 

If you put it in SD mode it will not look at the MAF and it should not have the Fuel trims you have. If it doesn't clear it up then it is something more. Check your TPS also for at idle it should be close to .67 volts that will affect alot of things also.

With your Fuel Trims are +20% it is running lean. And with it running that lean it is trying to add large amounts of fuel in a short time. Is probably why there is such a large movement from rich to lean. BLM's are really made to do small adjustments actually. I'm willing to bet that Your VE tables are not set to well.

I suggest tuning SD mode first. Then if you want to use closed loop.....tune that afterwards.

But remember to lock it into SD mode.......you can't just unplug the MAF. In LT1 Edit there is a switch on the first screen when you select the file you want to use. I shows your VIN and anything else that is on or off. VATS, EGR, etc. And then also under the fueling table I put 155 in both slots under the closed loop enable temp. Christian Millard suggests 255 but I can't put that in LT1 edit....... 150 is max. But that is like 300+ F degree's anyways. Then I go in and shut the PO102 and PO103 in the hardware verifcation so it wont trip the Hi and Lo MAF codes.

Some will argue that closed loop doesnt use the VE tables, I read of someone that had tested that and found that when you zero out the VE tables that closed loop throughts fits. It supposedly uses it as a referance. I havent had time to test it yet.....but I am going to just to verify it. And arguing case of tuning SD mode is that if a sensor goes bad in closed loop your power and drivablity will not be effected anyways.


There are some modded cars that all they can run is the SD tune.

 

In order to put it in closed loop i need LS1 edit, HP tuners or some sort of programer??