I Think I'm Running Lean...

[~JM~]

Just hooked up my ScanMaster & went for a drive earlier today. The O2 is all over the place. At the high end I'm seeing readings in the high 600 range, but it bounces between 300 & up. I had one chance to floor it & when I glanced down I had high 600 with 7 degrees KR. That's when I let out of it.

What should I do with this information?

Thank you
~JM~

 

[jasjamz]

Can you start with giving this info:
Outside temp
boost level
fuel pressure at idle vacuum line off/on
chip type: street, alky, race?
Did you set the TPS as TT suggested?

 

[blackgn1]

Looks lean with the info so far. Turn the boost down now!! 30lbs injectors?

 

[Pronto]

Did you get a boost gauge?
Unless you want to pick up the pieces of your engine with a shovel, don't go into boost until you resolve running lean. In another one of your threads I posted a link that has a pile of information on tuning, fp, knock etc. You need to study it. Something that you need to truely respect is how fast damage can be done when going into boost when lean. The issues you are having are not unsolveable, infact they are pretty normal for someone unfamiliar with TBs. You need to take a step back and go over all the info before wailling on it again.

 

[rmar]

^^^^^^^^^
What he said..........:biggrin:

 

[~JM~]

Can you start with giving this info:
Outside temp
boost level
fuel pressure at idle vacuum line off/on
chip type: street, alky, race?
Did you set the TPS as TT suggested?

I'm guessing that the outside temp was in the mid 50's
Boost level is stock
Fuel pressure is within spec the few times that I've checked. I believe its 43#'s
TT street chip burned for 92 octane
TPS is within range

I do not have any adjustability on boost. It's the same as stock.

I still have the OEM exhaust with an old cat-can. I also have a new 3"DP & the Pypes cat back system waiting to go on. Once the new exhaust is installed I believe it will be even more lean than what it is now. I do not have an adjustable FPR. I've been reading the instructions on how I can add fuel with my chip, but I usually disconnect my battery when I know I'm not going to drive the car in the next day or two so I will end up losing my settings.

Pronto could you please redirect me to the post that you are referring to?

Does the O2 readings on the ScanMaster usually hold fairly steady, because mine is not? Is it possible that I need a new O2 sensor?

I am taking this seriously & cut my driving short today until I get a better handle of whats going on.

Thank you
~JM~

 

[blackgn1]

The 02's will jump around. You could still be over boosting. The adjustable regulator is important. You need to verify your boost or you will need a shovel.

 

[ZNix]

I think adding a FMIC would lower the intake temperatures, making the air more dense, and therefore it needs more fuel. OR It could have gained a few pounds of boost from the intercooler. I would get a boost gauge on it ASAP.

Nix

 

[jarredsoon]

Boost gauge and a new O2 sensor for sure, I thought I was running lean as my o2's were all over the map and then I got a new o2 sensor and they were 800 steady

 

[Nick Micale]

...........What should I do with this information?
Thank you
~JM~

The key words are in your title, "I think...

Certainly knock can be caused by being lean, but there is also another major factor - not enough octane.

When testing a new build, or a car I am not familiar with, I always add some race gas to assure no damage while I am setting it up.

You certainly need a boost gauge, as with your current set up, you may only be able to run 12-14 psi or less, instead of the stock 16 psi with your local pump gas. You need an adjustable wastegate to go lower with your boost.

As you add parts and gain data, you then are able to dial up the boost w/o knock retard until you find your desirable settings.

You probably will need an adjustable fuel regulator, as there is no way a stock one will provide 43 psi base fuel pressure?

It is best to be safe rather than sorry.

 

[Pronto]

NEVER trust the stock boost gauge. It's a joke. Just b/c you don't have an adjustable boost actuator does not mean your boost is "stock".
You NEED an adjustable fuel regulator. The TT chip is set for 43lbs fuel pressure with the vacuum line off at idle. FP must rise 1/1 with the boost pressure. So if it's set at 43 it should be 53 at 10lbs. That can make you lean and ruin your engine.

The O2s should jump all around and move fairly quickly. At WOT they should settle to a small range. Most consider 780-820 the "safe" range but the stock O2 is narrow band and does not show the whole picture.
Vortex Buicks Lots of info hear in a straight forward format.

 

[~JM~]

Pronto, Thanks for the link. I have read through that site before but will go through it again.

Even though I do not have an adjustable FPR, I do have an upgraded Bosch 237 regulator. I have seen this type of FPR on a "Stock Appearing" GN that was running 28#'s of boost.

Is it possible that I need larger injectors? The P/O had some new 30# injectors installed just prior to the sale of the car. Should I upgrade to 60# injectors & have a new chip burned?

I will pick up a boost gauge here shortly. It also sounds like I need an adjustable wastegate actuater.

Nick, How do you determine how much boost you can safely run on pump gas while running race gas?

Thank you
~JM~

 

[jdpolzin]

Every car reacts different. Thinking your car is at stock boost is leaving it in huge different range of boost levels. I've used unadjustable stock wastegate actuators that made the car run at 21# of boost. You need the gauges to verify where you are. As far as your injectors, for a 92 tune, your injectors may be enough. But, straight 92 doesnt do much to prevent the motor from knocking. You shouldnt really be over 12-15 pounds of boost max on 92. As far as your regulator, you still need to verify where your fuel pressure is. Just becuase it has a 237 regulator means nothing. Your pump might create more pressure or less pressure than a stock pump, you wont know until yu check Most TT chips are designed to run at 43# of pressure with the vacuum line off. Again, you need to verify this. Just take a little bit of time to verify things before you have to put a whole lot of money into a nnew motor. -----Jeremy

 

[Pronto]

I believe Nick is refering to using some extra octane to knock while sorting out all the issues you need to address. Once you can run at something in the 14lb range with 0 knock then you start the tuning process with the highest octane you will normally run which in you case seems to be only 92. Depending on how things go you may not be able to run 14lbs without knock or it be fine until 18. Each car is different.

 

[Ttype6]

You need a scanmaster to monitor spark retard,a fuel gauge that you can see while you're driving so you can monitor full boost fuel pressure,and a boost gauge.

 

[~JM~]

Thank you for the many replies. So far I have ordered a new adj. wastegate actuater & an adj. FPR. I have also picked up a vacuum/boost test gauge that I have taped to my windshield for the time being. I verified my fuel pressure at idle & its still at 43# with the vacuum off. Unfortunately my fuel pressure test gauge doesn't have a long enough hose to make it to the windshield so I can watch it while I drive. Now I just need a day or two of dry weather to try it again.

~JM~

 

[gmmuscle]

get the metco fuel pressure gauge and it will fit under the windshield/wiper trim at the bottom of the windshield. I live by that while under boost. Had an issue today when I nailed it and got 5.7 Kr and noticed the gauge reading was all of a sudden lower than usual under WOT and got out of it. Something in my FPR?

Carl

 

[~JM~]

O.K. I have installed the new adjustable FPR & waste gate actuater that I picked up from Kirbans. I have not had the chance to drive the car due to the weather. I have increased my base fuel pressure to 45# with the vacuum line off. I have also used the adjustment feature of my TT chip to add the most fuel throughout the operating range. My O2's are still low at idle. They seem to settle in the 500 range for the most part. I'm beginning to believe that either my chip or my injectors may be too lean/small after I removed the OEM air cleaner & replaced it with an open element filter. I had the lean readings prior to the installation of the FMIC so I don't think that is the only problem.

Should I try to increase my base fuel pressure even more? The FPR directions make it sound like I can turn it up to 50#. What else should I try. I'm almost tempted to exchange my TT chip for my previous no name performance chip just to see if there is any difference. The old chip has no documentation other than the P/O said he put a 50HP chip in the car.

Thank you
~JM~

 

[ZNix]

Put your base fuel pressure back down to 42 line off. The turbotweak chip requires this. Idle 02's are not really that important. I would like to see readings from WOT.
Nix

 

[blackdeathtrap]

what are your int reading and blm readings as well