scanmaster O2 readings

[mister2]

I just bought a T type with a scanmaster in the car. I notice that on the highway when i go WOT i initially get some really lean o2 readings. 0xx milivolts. then after 1 or 2 frames later it will read the normal rich reading. Is this just a product of the slow frame rate of the scanmaster or is my fuel system not reacting fast enough to me suddenly stepping on the gas pedal? I just replaced the o2 sensor. the car has 42.5# injectors, upgraded fuel pump w/ hotwire kit, TA60 turbo @ 16 pounds of boost. fuel pressure is set to ~50# static. I am completely new to how these ECM's work, is this initial lean reading normal? Thanks for the help.

 

[mister2]

any help??

 

[turbot2112]

how high are your 02s going. 50 pounds static sounds way rich, what chip you got.

 

[mister2]

it will go up to about 800+ but it will almost always be initially very lean. It will also vary alot, sometimes 820+ sometimes 760. I am replacing the fuel filter tomorrow, previous owner ran a few tanks or leaded just before i got the car, just replaced the o2 as well.

 

[mister2]

I am looking through the paperwork to see what chip it is running, it says here on an invoice from Ron's Custome Automotive (kenilworth, NJ) that it is a ra93 chipa for the 009 injectors. I adjusted the fuel pressure down to what the chip literature recommends, (43#) and now i am consistantly getting 0xx mil volts at WOT. It won't show rich now at all. It is regristering 255 for L8 so i am assuming it is trying to enrich. i am also getting some knock, a few degrees. It was fairly cold this morning and i was getting 17# of boost. I turned it down to 15# last night when it was warmer. Please help!!! could it be just a clogged fuel filter? I will replace today if i get home before the sun goes down.

 

[turbot2112]

what are your blm readings at idle, and also while cruising.

 

[bruce]

Tip-in leaness is typical of most chips.
Also, why so many guys wind up changing to loose converters.

Doing your own chips and really learning now to tune a chip would be the best cure, since then you could really taylor the chip to you and your car.

 

[mister2]

The BL readings are at 126 at idle. and 126-160 when cruizing. I momentarily WOT a few times and the BL did not go up at all. I don't know if that is normal. sometimes it would stay at 126 and my o2 would go real low. I figure that the BL should try and enrichen at WOT but it is definitely not. anyboost makes the o2's read vary lean. Please help right now i am basically driving a 3.8L NA. It has a 3000 stall converter in it, but even if I let it wind up alittle (2-3 frames) it still stays vary lean.

 

[turbot2112]

126 is good but 160 is way lean. something is definately up. sounds like you may have a vacuum leak or something.

 

[colby]

I was going to post about almost the same problems, my 02's are reading in the 660 range in 3rd gear. I know I'm not running lean because should have enough fuel (009's,reg.,wal340,hw kit),I'm running a PT54 18-20psi w/no knock? I suspecting a bad 02 sensor, maybe maf & knock sensor also. Any ideas?