[kuku]

I borrowed a scan tool from an auto mechanic and this is what I showed:

At idle
Rpm 1000
Loop Closed
Exhaust 02 Lean
TPS: .46
Block Learn: yes
IAC: 25
A/F learned: yes
LV8: 34
MAF: 6
02 Cross count: was all over the place, it would not stay consistent showing 5,14,15,9
Coolant: 183
MAT: 102
Propor Step: Lean
TCC Command: P1
INT: 123

While under WOT the 02 cross count would show as low as 0 and 1.

I received two error codes 23 and 45. I know the 23 is a MAT sensor issue and does not affect the cars performance due to the car setting default of 82. I am not sure what to do about the 45 but have read into it. Any help would be great.

<small>[ August 10, 2003, 06:21 PM: Message edited by: kuku ]</small>

 

[Supersix]

I am by no means a "guru", but a few things stand out to me. THe idle is too high, your TPS is a little high, and a consistent LEAN indication may mean a cracked header, vacuum leak, or bad o2 sensor. Code 45 is a code for o2 sensor RICH though.

dunno

 

[ES]

What I look at are 02 numbers not the cross counts and blm numbers.
I do not see where this scantool indicated these.
Other than idle high, other numbers look in line.

 

[Steve Wood]

http://www.vortexbuicks-etc.com/code_45.htm

The cross counts are an indicator of a healthy o2 sensor as it should be crossing from lean to rich frequently.

Strange that the O2 read lean, this would make the ecm add fuel.

It would be helpful to have actual o2 variation as well plus actual blms so we could understand what is going on.

The idle is too fast and .46 v is on the edge of being too high which would cause a fast idle. But, I don't think that is the problem here. I would lower it a notch tho.. 0.38-0.44 would be safer. Does not matter which.

Maf looks about right so that is not making it go rich. A high number will.

A vacuum leak, or running too lean will kick the idle up, also.

O2s and blms would help a bit.

 

[kuku]

Thank you everybody for responding to the post. I have been chasing down a knock issue with my car since it was rebuilt. Steve I use your web site very often looking up codes and trying to solve my knock issues. The car will not get above 10lbs of boost without extreme knock.
I did notice the Casper gauge would show knock but the scan tool would not in low knock instances.

I am not sure why the scan tool does not show 02 voltage. I will have to buy a voltmeter and see what it is idle.

I also have been noticing a noise on the driver’s side like I have a cracked header. I read somewhere they are prone to crack between 3 and 5. I will also look for that.

Any other ideas for chasing down knock would be greatly appreciated. Just give me your ideas and I will start trying them.

For a winter project I would like to add a DYI Alcohol Injection System but want to make my car is running correctly before adding more power.

On a positive note my power antenna started working today. I thought it was tore off sometime but then turned on the radio and it raised. I cleaned a lot of the switches last week and must have cleaned the one to the antenna.

<small>[ August 10, 2003, 10:14 PM: Message edited by: kuku ]</small>

 

[Steve Wood]

Buy a Scanmaster or borrow turbolink from someone. You need to sort it out and it is next to impossible without a scantool.

Old age has made these things really flaky.

Usually you can see the crack in the header....it will often leak more when cold before the metal expands. If you are careful not to burn yourself, you can feel it....

Or if you are prepared to be horrified, pour a little top cleaner in the tb and watch the smoke come out all the leaks.

 

[Just a Six??]

Steve,
What is top cleaner & do i just unhook the up pipe & add? My car is louder until it warms up and maybe I have a cracked header??
Thanks

 

[Steve Wood]

GM sells a can of stuff called Top Cleaner...it is pretty potent stuff when it comes to removing carbon, etc.

The normal procedure is to pull the up pipe out of the ic and rotate it so it is pointing up instead of down. Pull the connector off the maf sensor, crank the engine and let it idle.

Trickle about two thirds of the can into the engine...it smokes like crazy and will irritate the neighbors if they are around. It will come out every crack, or bad connection in the exhaust system.

Pour the last third into the engine so that it kills the engine. Let it sit for a bit...pull the plugs, spin the engine over, then put new plugs in it, and restart.

 

[ULYCYC]

Make sure you change your oil after using top engine cleaner. Best to do when oil change is due so you don't waste fresh oil.