All Stock GN, but am getting Knock on Scanmaster. SM reading are listed....

[Chrisk]

So I took out my GN after getting a SM and noticed that at about 10-12psi of boost I get Knock retard of 5-6 degrees. At full throttle the SM recorded 10.4 degrees! O2's were 421??
Crusing and lower boost the O2's are in the 700-800's. I also noticed at idle my IAC reading is a dead 0, but while driving its 11 and up? Could be my IAC solenoid.

Here are my reading at idle.
AF 06
L8 32-33
INT 128
BL 129
ATS 123
TPS .40
IAC 00

What could be going on?

Thanks
Chris

 

[ES1]

My guess would be a stock chip with to much timing.
I would get a Turbo Tweak chip.
I would get the IAC set to 10-20.
You will need to reset the TPS.
I run 00 on IAC with no problems.

 

[QUIP'6']

So I took out my GN after getting a SM and noticed that at about 10-12psi of boost I get Knock retard of 5-6 degrees. At full throttle the SM recorded 10.4 degrees! O2's were 421??
Crusing and lower boost the O2's are in the 700-800's. I also noticed at idle my IAC reading is a dead 0, but while driving its 11 and up? Could be my IAC solenoid.

Here are my reading at idle.
AF 06
L8 32-33
INT 128
BL 129
ATS 123
TPS .40
IAC 00

What could be going on?

Thanks
Chris

if you say it is 100% stock then i would think of upgrading feul system with a walbro and hotwire sounds like the motor is starving for fuel

 

[BlackMetal]

I started out ownership of my GN with it in stock form too and yes, detonation occurs. ES1 and lpaulabbot are both right, start with upgrading the fuel pump and getting a TurboTweak chip to tame the timing.

Also try a RJC PowerPlate, that also helps reduce knock by evening out the airflow in the intake.

You can still do "mods" like these and call the car stock, if that's your goal.

 

[Quiky One]

Upgrade the AFPR and fuel pump along with chip. Lower boost to 15 and you wont have knock. Believe it or not after 20 years the fuel pump is weaker as is the AFPR. Does you car have any problem starting? If not, do not mess with the IAC. Take it from experience please. My TTA has read zero for 3 years now and I have never had a problem starting it, idling it, or any tip in issues. The stock chip has way to much timing for todays gas.

Jason

 

[Jerryl]

Don't forget about the MAF sensor.
If it does not get up to 255, you car will run lean.

As stated, verify /replace the fuel pump, sock, filter, add HW.
IMHO, while the TT chip is MUCH friendler for today's gas, not sure you should get that much KR with the stock chip at low boost if everything else works like it should.

 

[Chrisk]

IMHO, while the TT chip is MUCH friendler for today's gas, not sure you should get that much KR with the stock chip at low boost if everything else works like it should.

This is what i was thinking. In stock form should the car have that much knock? even at half throttle? I did also think that the fuel pump may just be tired...

 

[tthorngen]

chip made for gas 20 years ago. not for gas nowa'days

 

[Sweet6]

I would guess fuel pump as well. My stock pump on my TTA started going bad and I could not get it past 60MPH on a full throtte blast without going lean. I changed the pump and the car ran prefect.

 

[Chrisk]

I will be putting in a new fuel pump this weekend!

What about the IAC reading 00 at idle? Replace the IAC?

 

[Sweet6]

I don't think the IAC at 0 is a big deal. Some guys actually like it at 0. But the part is only $40 or so. So you could change it if you want.

 

[RT87]

I had the stock chip in my car since I bought it in 1987, and I saw KR numbers just like yours with the 91 available here.

I finally decided that if you have to run 94 with a stock chip to avoid KR, you might as well go with a modern chip with 20 degrees of timing and a little more boost to get the benefits of what has been learned in the last 20 years.

Keep the stock chip around in case of emissions testing.

 

[Sweet6]

IL no longer does emissions tests for any OBD1 or oler car. So 1995 and older you are in the clear. :biggrin:

 

[Chrisk]

I had the stock chip in my car since I bought it in 1987, and I saw KR numbers just like yours with the 91 available here.

I finally decided that if you have to run 94 with a stock chip to avoid KR, you might as well go with a modern chip with 20 degrees of timing and a little more boost to get the benefits of what has been learned in the last 20 years.

Keep the stock chip around in case of emissions testing.

93 is the best here unless you to 100 and its about 5-6$ per gal.
I got an alky kit waiting to be installed as well. I just wanted to get the car in perfect running condition before adding all the mods.

 

[RUQWKNF]

Don't forget to change the factory fuel filter while you are doing all these mandatory fuel system upgrades. And your TPS reading is a little low. I always set mine between .44 - .46 at idle and checking to make sure it would go to 4.5v -4.7v under WOT. It really just depended on what the car liked.
Just a couple of thoughts.

Patrick

 

[Ttype6]

I will be putting in a new fuel pump this weekend.

Don't buy a pump until you've proven it to be bad. You'll need a guage that can be read from the cockpit while driving. If the pressure drops while the motor spins faster,you have a fuel issue. It could be as simple as a clogged filter. Hot wiring the pump will help,also. A common cause of knock is an old injector harness. The wires going to the #1 cylinder have to cross over the hot EGR valve.If they get burned enough,that injector will stay on all the time. This creates a rich condition in the #1 cylinder. Since the o2 sensor reads all cylinders combined,it doesn't know which one is causing the problem and leans out all of them. You still end up with #1 being rich and the rest lean. If this is your problem,your #1 spark plug will be noticably darker than the rest. The fix is a new injector harness from Casper.

 

[Quiky One]

The pump doesnt go bad, it gets weak...

 

[Chrisk]

Im putting in a bigger pump and a hot wire kit.

 

[Chrisk]

Don't forget to change the factory fuel filter while you are doing all these mandatory fuel system upgrades. And your TPS reading is a little low. I always set mine between .44 - .46 at idle and checking to make sure it would go to 4.5v -4.7v under WOT. It really just depended on what the car liked.
Just a couple of thoughts.

Patrick

Thanks Patrick!!