high WOT O2"s and Knock

[turbojoe]

I have finally fixed my high blm problems (cracked header repaired) and vacuum leaks fixed. Now I am plagued with high 02's and kr at about 4-6 degrees. i ahave tried turning down the fuel pressure from 43 static to about 39-40 psi to no avail. my blms are right around the 126-128 mark with the fuel pressure set to the lower static setting (38-39psi). The car does not break the tires loose or chirp the tires for that matter. what gives??? I was thinking of replacing the 20 year old tired stock injectors. could they be what is holding the car back and could new injectors get my o2's and Knock in line?

scanmaster #'s
blm=126-128 @ idle/will go down to 118-119 with higher static fuel pressure
coolant=187
cc=0-251
volts=13.2-13.8
tps=.44
iac=21
maf=5-6grams
o2's @ idle fluctuating above & below .45 (as high as .750 something)

Car is all stock and that includes turbo and torque converter.
-brake torqued the car to check stall speed and tires begin to overcome brakes at about 2300 rpm @ about 5lbs of boost

 

[suicide six]

What kinda WOT #s? 20 yr old injectors should be changed,they were marginal when new and w/a modded car even worse.What chip are ou running?This may very well be a problem also.

 

[turbojoe]

sorry suicide six, you are fast on reply. I added some of those #'s up top.

- anyway, the only Wot or 3/4 throttle #'s i have are the 02's and knock
-the highest 02's i have seen were about 870 or so. Kind of high or rich to me
-highest Kr was in the high sevens/low 8's

 

[turbojoe]

It puzzles me because all or most of the scanmaster #'s look right on. I thought for sure that fixing my header problem would wake this car up, but now this problem. -I also checked the #3 exhaust valve/rocker and it looks good and is rocking as much as the others (1 & 5). So i guess that rules out the wiped cam lobe thingy, at least on that side (havn't checked other side yet).

 

[750H.P.V6]

What are your wide open throttle O2 #'s? How much boost are you running? What octane fuel do you have in your area? What are the ambient conditions?

Neal

It puzzles me because all or most of the scanmaster #'s look right on. I thought for sure that fixing my header problem would wake this car up, but now this problem. -I also checked the #3 exhaust valve/rocker and it looks good and is rocking as much as the others (1 & 5). So i guess that rules out the wiped cam lobe thingy, at least on that side (havn't checked other side yet).

 

[turbojoe]

Running stock boost pressure (15 psi) as i have adjustable actuator rod set to 5 1/4 inches. Octane=93 pump gas, O2's at WOT average around 850-870 w/ KR registering about 2.8-6 or 7 degrees. Looks to be happening at mostly mid 30's mph (36 or 37 mph) according to scanmaster. Ambient temps in the low to mid eighty's w/ humidity. O2 sensor replaced in the fall prior to putting car to sleep for winter. knock sensor is newly installed, fresh module and coil pack, plugs & wires, cleaned intercooler, throttle body cleaned, pcv valve new. to keep it short, everthing is newly replaced or in good working order as far as i can tell. the scanmaster #'s seem to be within parameters.
ALSO; new original MAF sensor installed. (had it sittin on shelf, never used)
NOTE: I am currently running a precision turbo & engine (aka Lubrant) 93 chip w/20 degrees of timing. I tried swapping in the stock chip and the car responds the same, high o2's and KR.

 

[750H.P.V6]

The O2#s are really rich for a stock chip which doesn't make sense. Keep in mind that the stock chip does have 22 degrees timing at WOT, and the stock intercooler isn't very efficient even on a good day. Sounds like the knock is occuring around the 1-2 shift. Does it subside if you keep going or get worse? A spike of KR on the shift is pretty common then there is a trickle down effect for the next couple of frames (on a scan tool). Could be a bad tank of gas. Is the gas in your area oxygenated?

Neal

Running stock boost pressure (15 psi) as i have adjustable actuator rod set to 5 1/4 inches. Octane=93 pump gas, O2's at WOT average around 850-870 w/ KR registering about 2.8-6 or 7 degrees. Looks to be happening at mostly mid 30's mph (36 or 37 mph) according to scanmaster. Ambient temps in the low to mid eighty's w/ humidity. O2 sensor replaced in the fall prior to putting car to sleep for winter. knock sensor is newly installed, fresh module and coil pack, plugs & wires, cleaned intercooler, throttle body cleaned, pcv valve new. to keep it short, everthing is newly replaced or in good working order as far as i can tell. the scanmaster #'s seem to be within parameters.
ALSO; new original MAF sensor installed. (had it sittin on shelf, never used)

 

[turbojoe]

I think the gas has a little ethanol in it, as far as oxygenated, i think only in the winter time blend. i drained old gas and put in fresh 93 octane (exxon). I havn't noticed if the knock goes away because i always lift when i first see the knock occurring. ALSo: i tried a Lubrant 93 chip w/ 20 degrees of timing and it responds pretty much the same way. (high 02's And KR) NEAL, i tried lowering my static fuel pressure as well to no avail. I am beginning to think that my stock injectors are not flowing like they should be, maybe causing a rich condition?

 

[750H.P.V6]

The puzzling thing here is the KR with a rich A/F ratio and a moderate amount of boost on 93 octane gas. If the gas has ethanol in it then it's oxygenated for what that's worth. Is this a new problem or something that has been a trend? Typically a mechanical problem (cam going flat for instance) gets progressively worse over time. If the KR is a transient condition due to a shift and then subsides it's far less of a problem than if you have continuous knock thruout a run. One last question: Do you actually hear anything or is it just the Scan master reading that you're seeing?

Neal

I think the gas has a little ethanol in it, as far as oxygenated, i think only in the winter time blend. i drained old gas and put in fresh 93 octane (exxon). I havn't noticed if the knock goes away because i always lift when i first see the knock occurring. ALSo: i tried a Lubrant 93 chip w/ 20 degrees of timing and it responds pretty much the same way. (high 02's And KR) NEAL, i tried lowering my static fuel pressure as well to no avail. I am beginning to think that my stock injectors are not flowing like they should be, maybe causing a rich condition?

 

[turbojoe]

It seems like the same problem that i have been having for some time now. NO, i cannot hear it knock whatsoever. Only way i know its knocking is by looking at the scanmaster. I did have a High blm a while back (140's) but i fixed that with the new drivers side header and some small vaccuum leaks.
I am still leaning toward the old stock injectors/maybe clogged, worn out and not spraying correctly? Maybe i'm getting Rich knock? I did check the #3 cylinder/rocker arm to see if it was moving the same in relation to others, and it is fine. This is usually the problematic one i think.

 

[750H.P.V6]

It's probably not a bad idea to have the injectors cleaned and flowed on a bench to quantify whether or not they are a problem. Just because they are old doesn't mean that they are bad but there could be a problem there. The thing is that to have the set cleaned and flowed is money you could put toward a new set of upgrade injectors. I guess you have to make the choice on that. Just as an experiment to see if the knock is bonified you might want to toss a couple of gallons of 100 octane in the tank and see what happens. Sorry I can be more insightful.

Neal

It seems like the same problem that i have been having for some time now. NO, i cannot hear it knock whatsoever. Only way i know its knocking is by looking at the scanmaster. I did have a High blm a while back (140's) but i fixed that with the new drivers side header and some small vaccuum leaks.
I am still leaning toward the old stock injectors/maybe clogged, worn out and not spraying correctly? Maybe i'm getting Rich knock? I did check the #3 cylinder/rocker arm to see if it was moving the same in relation to others, and it is fine. This is usually the problematic one i think.

 

[suicide six]

Was the knock sensor torqued correctly?What type of maf was replaced,stock type or auto store type?I dont believe yor injectors are clogged although they may not be spraying very well.Our cars arent crazy about this gas blend.I would start there and do the easy things before throwing money at new parts and maybe adding to your problems.

 

[turbojoe]

Knock sensor was torqued correctly @ 14 ft/lbs. i did it twice to be sure. The maf is a Stock Original maf sensor bought from Kirbans private stock when i purchased the car from him. Stock injectors are 20 years old, i will replace them with MSD 50 lb'ers and a matching 93 octane chip and see what happens i guess. I have already thrown a ton of money at the thing, whats another 400-500 dollars

Like i mentioned before; the scanmaster #'s are all within parameters, if not dead on. Blm's @ 126-128! the drivers side header was replaced w/ an atr unit. pass side appears to be ok. torque converter is a D5 and car brake stalls at about 2300 @ 5-6 lbs of boost. STILL the car will not break tires loose! The oil smells of fuel after only 50-100 miles of use or driving. My guess is the injectore are not spraying correctly, leaking down or something
The rest of the fuel system has been upgraded, Hot wired pump, walbro fuel pump, adjustable regulator.

 

[85HOT-T]

Try holding WOT a few seconds anfter your shift to see if you knock goes away. Could just be a pipe hitting.

 

[turbojoe]

If its a pipe hitting, how do you explain the high 02's though?
Shouldn't the 02's be in the lower 800's at wot?

Neal, I will try and put some xylene or toulene in the tank as I do not have 100 octane fuel available in Mass. (not near me anyway). Thanks, I'll post again to let you know if that helped or not. :smile:
I also ordered up some MSD 50's and a Lubrant chip burnt for these injectors,
hopefully they will also help.