New Turbo Buick Owner - Frustrated with Knock read from Scanmaster, help appreciated

[Hatdragracer]

Bought my car modified...seems to run great, but once I started paying attention to the retard numbers on the scanmaster I have become worried.

My boost controller (a really cheap feeling plastic valve) seems to have some issues, as I dont seem t0 be able to turn the boost below 15 psi?

It has an oversize turbo, stock intercooler, Fuel pressure is @40 at idle

At 15 psi: O2s would read 840-910 with 6-7 degrees of retard
At 17 psi with Alky: 840+ with 7-8 degrees of retard

With the O2's it doesnt seem like it is running lean....any other ideas?

 

[Hatdragracer]

A friend here in Houston suggested a RJC air distribution plate, and that the rear cylinders might be getting more than their share of the boosted air? Does that sound plausible? I just hate to throw parts at it. I am about to put my scanmaster in a bucket of water and just enjoy driving the car! I have never actually heard any pinging from the car.

 

[blackgn1]

Have you looked to see if the downpipe is hitting the frame? Or other causes of false knock. 02's look ok but the narrow band isn't the best way to get a good reading. Next place to look is fuel pressure at WOT. The power plate will equal out the air flow but air flow isn't your problem. Also confirm that the boost gauge is accurate.

 

[blackgn1]

Much knock and you will enjoy just looking at the car. The headgaskets will pop. Get the car running right then you can enjoy it. A part of owning these cars is having to work on them from time to time. Any knock is bad. Scanmaster is your best friend right now. Don't ignore the information it gives you. Post up the readings after the car warms up.

 

[QwuickTurbo6]

maybe your downpipe is hitting the a arm when the motor is under load. Mine did this and showed 10-12 degrees false knock

 

["Reaper"]

Check your motor and trans mounts. Have you done the spring cleaning check list?
http://gnttype.org/maint/basics.html

 

[87-WE2]

Hold up everybody. He says 17 psi + alky he gets 7-8 KR with o2s 840+. I thought alky wasn't supposed to do that. Could this be rich knock? Just a thought.

 

[blackgn1]

Sure that's possible. Without more information we are all just guessing. With some WOT fuel pressure readings we have a starting point. I would like to see those readings and a confirmed boost reading. I am hoping there is a boost gauge installed but still just guessing. Scanmaster readings would be nice. We need a starting point. Is there a alky chip? Does it match the combo? What is the combo?

 

[we4Mateo]

Hold up everybody. He says 17 psi + alky he gets 7-8 KR with o2s 840+. I thought alky wasn't supposed to do that. Could this be rich knock? Just a thought.

x2. Make sure you really only look at O2's at the top of third after a good pull but those numbers seem rich, and that will cause knock. 800 is safe with alky at those boost levels and still probably too rich. My car is consistant with alky at WOT in the 10.5 to 10.8 AFR range but NB O2 values on the scanmaster can read anywhere from 750 to 825 at the same AFR. You're guessing with the NB but my guess is that it's still too rich. You should have no knock with alky and turn timing down until you have none and remove some fuel and see where that gets you.

 

[Hatdragracer]

I have ordered a new boost gauge...I didnt like the old one anyway. Apologies that I dont know the full scope of the car modifications. I believe it to be an alky tune as the alky system was installed by the last group to tune the car (Boost Performance in Amarillo) I called them and they could tell me very little about the car as they kept no records.

All the previous owner could tell me "The engine has a stock rebuild with forged pistons that has less than 3,000 miles on it along with a freshly rebuilt transmission done at the same time as the engine rebuild. The trans had a stage-right t-brake installed by the previous owner, but to my knowledge has never been used. Car has a Precision PT-52 turbo, 3" single shot exhaust with a 3" internal wastegate and a Flowmaster muffler."

Again...forgive the ignorant questions, but without getting a new chip burned how would I adjust the timing, or remove some fuel? Is there a way to do this through Scanmaster.

I will also start by checking the basics tomorrow for things like the downpipe hitting the a-arms or frame and looking at my plugs tomorrow...I truly appreciate all the advice.

As far as someone asking for the rest of the Scanmaster readouts...should that be done with the engine warm and running?

 

[3.8L V-8 eater]

Judging by the numbers you have given both with and without alky your knock could very well be false...Get it up to 3rd gear and gradually roll into the throttle and watch for knock. If your in 3rd and roll into it and see no knock you have to find out where the false knock is coming from....If you roll into it and see knock let off immediately....Take someone with you to watch the scanmaster while you drive....I'm betting it's false knock, but then again we need more info...Find a local TR guy who can help you figure out what you have and if it's healthy for you start modding and so on.....

 

[NOTSOFAST]

I have ordered a new boost gauge...I didnt like the old one anyway. Apologies that I dont know the full scope of the car modifications. I believe it to be an alky tune as the alky system was installed by the last group to tune the car (Boost Performance in Amarillo) I called them and they could tell me very little about the car as they kept no records.

All the previous owner could tell me "The engine has a stock rebuild with forged pistons that has less than 3,000 miles on it along with a freshly rebuilt transmission done at the same time as the engine rebuild. The trans had a stage-right t-brake installed by the previous owner, but to my knowledge has never been used. Car has a Precision PT-52 turbo, 3" single shot exhaust with a 3" internal wastegate and a Flowmaster muffler."

Again...forgive the ignorant questions, but without getting a new chip burned how would I adjust the timing, or remove some fuel? Is there a way to do this through Scanmaster.

I will also start by checking the basics tomorrow for things like the downpipe hitting the a-arms or frame and looking at my plugs tomorrow...I truly appreciate all the advice.

As far as someone asking for the rest of the Scanmaster readouts...should that be done with the engine warm and running?

If George at Boost Performance did the tuning then your ok. as George is pretty much the go to Guy in the panhandle for these Bad Boys. like others have stated, more then likely you have false knock or Rich knock.

 

[Pronto]

Is that fuel pressure measured with the vac line off? Most chips are set for 43 with the line off. Check the dp for dents under the area of the A arm. Not many run a Flowmaster muffler, everyone I know that had one and replaced it had a noticable improvement in performance. If you have a TT chip you may be able to adjust the settings. Give us the Scanmaster numbers driving normal with it warmed up.

 

[BIGPSI]

Is that fuel pressure measured with the vac line off? Most chips are set for 43 with the line off. Check the dp for dents under the area of the A arm. Not many run a Flowmaster muffler, everyone I know that had one and replaced it had a noticable improvement in performance. If you have a TT chip you may be able to adjust the settings. Give us the Scanmaster numbers driving normal with it warmed up.

x2 ,if you have a turbo tweak chip you can pull timing and fuel .i have gotten knock from being to rich, o2's should be around 750-780 on the scanmaster, as stated before you need a decent 3rd gear pull to be more acurate

 

[Mike Licht]

Does the car still have the alky system? An alky tune without alky will do this

 

[Hatdragracer]

Tried to turn boost down, I know the boost gauge needs to be verified two more runs today at 3 rd gear (previous data was from 1st gear)
The first run pulled hard: 834 - 0 retard - Alky system on - 16psi boost
Second run was like hitting a brick wall: 863 - 13.1 retard - Alky system on - 16 pis boost - yikes!

Fuel pressure @ idle with vacuum line hooked up - 43psi, @ idle with vacuum line disconnected - 50 psi

Scanmaster numbers with car warm an in gear
After Runs
AF - 04
L8 - 37
Bat - 13.4
Int - 132-124
bl - 137
mph - 0
clt - 193
ATS - 138
r - 700
tps - .46
iac - 16
cc - 99-105 - This was very different from sample 2
mal - 00

After Runs - just before shutoff
AF - 04
L8 - 37
Bat - 13.4
Int - 124-128
bl - 138
mph - 0
clt - 193
ATS - 135
r - 700
tps - .46
iac - 14
cc - 16-25 - This was different from sample 2
mal - 00

I could see where the downpipe was close to the frame and a-arm, looks like there may have been some cantact by the frame (just under firewall)
I plan to look at the plugs tonight once it cools down.

 

[huntsg]

What type of MAF do you have? Stock? Gen 2? If you have a stock one it could be bad and leaning out the system at WOT.

 

[Hatdragracer]

it is the stock MAF....I did take off and clean with MAF cleaning spray recently.

 

[Pronto]

Try the adjusting the fuel pressure to 43psi at idle with the line off. That's what most chips are set for. The CCs should be continuously cycling not stuck or slow turning. It shows the health of the O2.

 

[3.8L V-8 eater]

Tried to turn boost down, I know the boost gauge needs to be verified two more runs today at 3 rd gear (previous data was from 1st gear)
The first run pulled hard: 834 - 0 retard - Alky system on - 16psi boost
Second run was like hitting a brick wall: 863 - 13.1 retard - Alky system on - 16 pis boost - yikes!

Fuel pressure @ idle with vacuum line hooked up - 43psi, @ idle with vacuum line disconnected - 50 psi

Scanmaster numbers with car warm an in gear
After Runs
AF - 04
L8 - 37
Bat - 13.4
Int - 132-124
bl - 137
mph - 0
clt - 193
ATS - 138
r - 700
tps - .46
iac - 16
cc - 99-105 - This was very different from sample 2
mal - 00

After Runs - just before shutoff
AF - 04
L8 - 37
Bat - 13.4
Int - 124-128
bl - 138
mph - 0
clt - 193
ATS - 135
r - 700
tps - .46
iac - 14
cc - 16-25 - This was different from sample 2
mal - 00

I could see where the downpipe was close to the frame and a-arm, looks like there may have been some cantact by the frame (just under firewall)
I plan to look at the plugs tonight once it cools down.

You need to pop the chip cover off that ecm and figure out what chip you have...That base fuel pressure is likely to high and you need to know if the chip was burnt for alky injection...