Running lean at WOT. Scanmaster numbers provided

[krisking94]

basically as the title states my car seems to leaning out on the top end. I knew something has been a little off on the car. During a WOT pull/ fun race I logged 726 timing at 4.2 degrees of knock. I know at WOT timing should be between 900-1000. During this run I went against one of my friends bone stock 99 Trans am, he won pretty convincingly. Granted this was a highway pull, not from a dig. I know it's not a accurate representation of our cars, but still should of been pretty even at least. 2 years ago the GN was dynoed at 300 WHP and 400 FtLb of torque to the wheels. Mods are Poston headers to THDP, RJC crossrflow exhaust. Manual boost controller, 39# injectors, SMC alky kit(single nozzle), believe it has a old school red Armstrong fuel pump(essentially a truck Fuel pump isn't it?), turbo tweak chip, fuel pump Hotwire kit, spark plugs and wires are not factory but cannot remember the info on them as they where on the car when I got it. Fuel filter is less than 5 years old(ac Delco). Ls1 MAF. I have the boost turned down to 18psi. Sure I am forgetting some stuff.

Scanmaster numbers at idle (warmed up)
AF -04
LB- 30-32
BAT - 14.0
INT - 128
BL - 136-142
CLT - 165
ATS - 75
Rpm - 725- 750
Tps - .44
IAC -27

PS. There is a small exhaust leak where the turbo and down pipe connect.

 

[krisking94]

I as well have the RJC AD power plate, EGR delete, CAI. Also under hood fuel pressure gauge reads 43 at idle. Don't know at WOT as I do not have a gauge hooked up in the cabin. I know it would better help understand what's going if I did.

 

[gusszgs]

Not sure what WOT timing 900-1000 means but you really need to get a Fuel pressure gauge taped to your windshield and monitor your boost to FP ratio. If your running 18psi of boost your FP should be approx 61psi

 

[DeltaBravo]

I think...the WOT timing is just a misunderstanding. I think the numbers he is talking about are the O2's or MV on his scan master.

But that is an assumption for now.

krisking94,
Have you read this?
http://www.vortexbuicks-etc.com/TuningBasics.htm

If not, please take the time to understand it...if your slow like me, I had to re-read it over and over until is sank in.

As gusszgs said, get a fuel gauge to trouble shoot with. If your local (Long Beach, CA), I have one you could borrow.

And lastly, I believe for a street tune, you want 820mv in your 3rd gear WOT pull. But most importantly, absolutely no retard! I would stop anymore full throttle pulls until this has been fixed.

 

[krisking94]

I think...the WOT timing is just a misunderstanding. I think the numbers he is talking about are the O2's or MV on his scan master.

But that is an assumption for now.

krisking94,
Have you read this?
http://www.vortexbuicks-etc.com/TuningBasics.htm

If not, please take the time to understand it...if your slow like me, I had to re-read it over and over until is sank in.

As gusszgs said, get a fuel gauge to trouble shoot with. If your local (Long Beach, CA), I have one you could borrow.

And lastly, I believe for a street tune, you want 820mv in your 3rd gear WOT pull. But most importantly, absolutely no retard! I would stop anymore full throttle pulls until this has been fixed.

Yes I was talking about 02s my apologies. Thanks for the offer in the gauge but I am in STL :/. For the 3rd gear pull I got the 900-1000 Mv recommendation from turbo tweak. And ya I'm definitely not doing any more pulls like that, I had to do 1 though just so I could pull some numbers up.

 

[krisking94]

Believe me it hurt me to do it

 

[DeltaBravo]

You mentioned you have a FP gauge on the rail, right? Just go get three feet of properly rated rubber fuel line and temporally install it and run your gauge under your hood. I did that and was able to monitor a 1/1 fuel pressure rise with boost. Just make sure the clamps are tight...don't want any fires.


Sent from my iPhone using Tapatalk

 

[krisking94]

You mentioned you have a FP gauge on the rail, right? Just go get three feet of properly rated rubber fuel line and temporally install it and run your gauge under your hood. I did that and was able to monitor a 1/1 fuel pressure rise with boost. Just make sure the clamps are tight...don't want any fires.


Sent from my iPhone using Tapatalk

Ah okay okay. I read over the link you sent me from vortex Buick(will be re-reading it couple more times) but my question is not about tuning about if my fuel delivery is sufficient enough for my mods. Is the car starving for fuel resulting in knock?

 

[DeltaBravo]

Couldn't say if your fuel is sufficient, only because we don't know what it is doing under boost. But the best test is watching your fuel pressure rising 1 psi/ 1 lb of boost while driving.

If your fuel pressure is 43 psi at idle, then with full boost (18 lbs) you should see at least 61 psi of fuel pressure on your gauge...that is extended from the fuel rail and routed under your hood.


Sent from my iPhone using Tapatalk

 

[earlbrown]

You've got some serious sorting out to do. You've got mods and whatnot but still making about the same power as it did when it was at the dealership.

You really need to make sure you have full pressure at WOT. Don't put that off any longer. If you have to, rent of the fuel pressure test kits from an auto parts store and see what you have.


That being said if you're showing 726mv at WOT, that's not lean. No idea what your A/F is since the stock O2 is a switch not a gauge. ....but you're definitely much richer than 14.7. How much, I have no idea. That's a function of how hot the sensor is along with the actual A/F ratio.

Have the basics been done like valve springs, timing set, etc....?

 

[dank GN]

You can adjust stuff in the chip. And agian earl is correct . Typical case of 10sec parts on a 12 sec car . You should do all the things in this spring cleaning section
http://www.gnttype.org/maint/basics.html

 

[Pronto]

You could be seeing an issue with the SMC alky kit too.

 

[Chuck Leeper]

5 y/o fuel filter?
If the fuel psi ga is a cheapo, silver dollar size, I can make a guess it's not reading accurately.
If you have 43 at idle, and the line is on, pull the line, and see where the psi is. It best be 3-7psi higher.

 

[whitehot1]

basically as the title states my car seems to leaning out on the top end. I knew something has been a little off on the car. During a WOT pull/ fun race I logged 726 timing at 4.2 degrees of knock. I know at WOT timing should be between 900-1000. During this run I went against one of my friends bone stock 99 Trans am, he won pretty convincingly. Granted this was a highway pull, not from a dig. I know it's not a accurate representation of our cars, but still should of been pretty even at least. 2 years ago the GN was dynoed at 300 WHP and 400 FtLb of torque to the wheels. Mods are Poston headers to THDP, RJC crossrflow exhaust. Manual boost controller, 39# injectors, SMC alky kit(single nozzle), believe it has a old school red Armstrong fuel pump(essentially a truck Fuel pump isn't it?), turbo tweak chip, fuel pump Hotwire kit, spark plugs and wires are not factory but cannot remember the info on them as they where on the car when I got it. Fuel filter is less than 5 years old(ac Delco). Ls1 MAF. I have the boost turned down to 18psi. Sure I am forgetting some stuff.

Scanmaster numbers at idle (warmed up)
AF -04
LB- 30-32
BAT - 14.0
INT - 128
BL - 136-142
CLT - 165
ATS - 75
Rpm - 725- 750
Tps - .44
IAC -27

PS. There is a small exhaust leak where the turbo and down pipe connect.

You need to start a maintenance schedule for your car. "The comment about the fuel filter being less than 5 years old" - Even if it's not causing any problems should be changed yearly. Any leaks should be fixed when you find them,they will only get worse if you don't.

Here is a link for Spring Cleaning basic maintenance that should be done on your car.

http://www.gnttype.org/maint/basics.html

 

[Eric Stage I]

For the 3rd gear pull I got the 900-1000 Mv recommendation from turbo tweak.

No, that's not something that came from me for a Buick. On most Buick scantools, we look for something around 780-820mv or so at WOT.

 

[Mr.Spool]

basically as the title states my car seems to leaning out on the top end. I knew something has been a little off on the car. During a WOT pull/ fun race I logged 726 timing at 4.2 degrees of knock. I know at WOT timing should be between 900-1000. During this run I went against one of my friends bone stock 99 Trans am, he won pretty convincingly. Granted this was a highway pull, not from a dig. I know it's not a accurate representation of our cars, but still should of been pretty even at least. 2 years ago the GN was dynoed at 300 WHP and 400 FtLb of torque to the wheels. Mods are Poston headers to THDP, RJC crossrflow exhaust. Manual boost controller, 39# injectors, SMC alky kit(single nozzle), believe it has a old school red Armstrong fuel pump(essentially a truck Fuel pump isn't it?), turbo tweak chip, fuel pump Hotwire kit, spark plugs and wires are not factory but cannot remember the info on them as they where on the car when I got it. Fuel filter is less than 5 years old(ac Delco). Ls1 MAF. I have the boost turned down to 18psi. Sure I am forgetting some stuff.

Scanmaster numbers at idle (warmed up)
AF -04
LB- 30-32
BAT - 14.0
INT - 128
BL - 136-142
CLT - 165
ATS - 75
Rpm - 725- 750
Tps - .44
IAC -27

PS. There is a small exhaust leak where the turbo and down pipe connect.

Fix the leak that will bring the bl down ,put a real fp gauge in the car verify fp,check the smc pump or better upgrade to alky control,replace fuel filter,tune the car for 800s on the scanmaster.just so you know your not going to pull on an trans am car in high gear with 18psi with stock motor so don't feel bad.now raising boost different story.

 

[krisking94]

You've got some serious sorting out to do. You've got mods and whatnot but still making about the same power as it did when it was at the dealership.

You really need to make sure you have full pressure at WOT. Don't put that off any longer. If you have to, rent of the fuel pressure test kits from an auto parts store and see what you have.


That being said if you're showing 726mv at WOT, that's not lean. No idea what your A/F is since the stock O2 is a switch not a gauge. ....but you're definitely much richer than 14.7. How much, I have no idea. That's a function of how hot the sensor is along with the actual A/F ratio.

Have the basics been done like valve springs, timing set, etc....?

Valve springs have been done. Cam sensor is about to be replaced. ( I can hear retaining nug wiggling around, especially on cold start)

 

[krisking94]

You need to start a maintenance schedule for your car. "The comment about the fuel filter being less than 5 years old" - Even if it's not causing any problems should be changed yearly. Any leaks should be fixed when you find them,they will only get worse if you don't.

Here is a link for Spring Cleaning basic maintenance that should be done on your car.

http://www.gnttype.org/maint/basics.html

And yes all of this spring cleaning maintenance has been done recently. Now not saying it does not need to be checked out again.

 

[krisking94]

5 y/o fuel filter?
If the fuel psi ga is a cheapo, silver dollar size, I can make a guess it's not reading accurately.
If you have 43 at idle, and the line is on, pull the line, and see where the psi is. It best be 3-7psi higher.

I'll have to do that test today.

 

[krisking94]

You need to start a maintenance schedule for your car. "The comment about the fuel filter being less than 5 years old" - Even if it's not causing any problems should be changed yearly. Any leaks should be fixed when you find them,they will only get worse if you don't.

Here is a link for Spring Cleaning basic maintenance that should be done on your car.

http://www.gnttype.org/maint/basics.html

The issue is my brother owned this car for the last 5-6 years and he did all of that recommended spring cleaning, but hardly drove the car. In the little under a year I have had it, car has probably seen the road more times then it in the last 2 years when my brother owned it. Car was running good then. Dynoed 300whp 400ftlb tq, no knock. But sadly didn't see the road much after, and not much tinkering. So ever since I've had it nothing has changed besides I had a THDP put on and cross flow exhaust. And now some knock is showing up.