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AEM wideband O2 sensor/gauge readings

corbinafly

corbinafly

"Mmmm. More please."
Location
lakewood,ca
Well, I finally had my first day of driving with the new wideband O2 sensor/gauge setup. No more crazy light show like you get with the autometer gauge.
Looks like I'm floating right around 14.6:1 AFR during idle and cruise. But at WOT, I start out at about 13.2:1 AFR at around 3000 rpm then it richens up to about 11:1 AFR at 5000 rpm. Looks like I need more airflow at the higher rpms? What do you guys think? I thought I was running lean at WOT with the injectors that I have but I guess not.
Here's my setup:
95 XJ, AW4
Hesco 4.6 stroker, 4.0 rods, forged pistons, 9.42:1 comp ratio
WJ intake manifold
Borla header, hiflow cat, and magnaflow muffler with all 2.5" pipes
stock 39 psi fuel pressure
Accel 21# injectors (flows about 20#/hr at 39psi)
Airaid cone type filter
stock throttle body
msd ignition, screamin demon coil

So you think I need to work on the intake system?
Any input would be appreciated.

K

By the way, I posted this on the yahoo stroker group too. Just want as much input as possible.
 
I thought 95 was higher fuel pressure than that? Anyway i would go with a bored throttle body and a newe" (99) irakd. t`t voul help apflnw a `t at h ah RPM's.

BTW how much did that Meter run you?

Dingo
 
$349 at Marren Fuel Injection (www.injector.com)

Unless, of course, you can get a deal on a couple more? No hurry - but I'd like to have two or so for tuning (and a semi-permanent mounting for experimentation...)

I wouldn't even bother using anything that responded to a "knuckle" sensor - just not any useful information there. WBHEGO is the way to go - or just quit with measuring AFR that way and use a pyrometer...

5-90
 
Doesn't the 95 HO have a 5200 RPM rev limiter in the computer?????

You may be aproaching the rev limit and fuel reading may be affected by this. What is the AF reading at 4500 RPM?
Does it stay at 13.2 until 5000?
Another thing - what cam and valve springs? If you have a Torque cam you may be floating the valves at 5000 RPM and AF ratio will be affected.
 
Where are you instaling the sensor? It will make a diference as to how far down the pipe it is, and also if you are using the stock hole with the stock sensor out, the computer is tring to adjust but not getting the right info.
 
rsalemi said:
Doesn't the 95 HO have a 5200 RPM rev limiter in the computer?????

You may be aproaching the rev limit and fuel reading may be affected by this. What is the AF reading at 4500 RPM?
Does it stay at 13.2 until 5000?
Another thing - what cam and valve springs? If you have a Torque cam you may be floating the valves at 5000 RPM and AF ratio will be affected.
Click to expand...
It's not the rev limiter. The AFR drops as the rpms increase. So there is no sudden drop at the high end.
It was built by hesco with the h264 cam. I'm not sure about the valve springs, but I doubt hesco would build it without the proper springs. They would see the problem when they run it on their dyno before shipping.

K
 
Panama XJ said:
Hesco Cam or stock Cam?? Stock valve runners or ported and polished??
Click to expand...
h264 cam, cnc ported head

K
 
XJJack said:
Where are you instaling the sensor? It will make a diference as to how far down the pipe it is, and also if you are using the stock hole with the stock sensor out, the computer is tring to adjust but not getting the right info.
Click to expand...
It's intalled in the bung provided by the Borla header for the stock sensor. The gauge sends a signal to the the PCM that simulates the signal from the stock O2 sensor so the PCM is happy. No DTCs.

K
 
corbinafly said:
Well, I finally had my first day of driving with the new wideband O2 sensor/gauge setup. No more crazy light show like you get with the autometer gauge.
Looks like I'm floating right around 14.6:1 AFR during idle and cruise. But at WOT, I start out at about 13.2:1 AFR at around 3000 rpm then it richens up to about 11:1 AFR at 5000 rpm. Looks like I need more airflow at the higher rpms? What do you guys think? I thought I was running lean at WOT with the injectors that I have but I guess not.
Here's my setup:
95 XJ, AW4
Hesco 4.6 stroker, 4.0 rods, forged pistons, 9.42:1 comp ratio
WJ intake manifold
Borla header, hiflow cat, and magnaflow muffler with all 2.5" pipes
stock 39 psi fuel pressure
Accel 21# injectors (flows about 20#/hr at 39psi)
Airaid cone type filter
stock throttle body
msd ignition, screamin demon coil

So you think I need to work on the intake system?
Any input would be appreciated.

K

By the way, I posted this on the yahoo stroker group too. Just want as much input as possible.
Click to expand...

The increasing richness as the rpm increase could point to restricted airflow or it could just be a quirk of the stock PCM programming. Replacing your stock TB with a 62mm unit would be a good start; you could even go for the Flometrics 66mm or 68mm unit and enlarge the plenum inlet opening to match.
Are you sure your injectors are only 21lb'ers? I would have expected at least 24's on a HO stroker. Even Hesco recommend at least 10% larger injectors than stock.
 
Dr. Dyno said:
The increasing richness as the rpm increase could point to restricted airflow or it could just be a quirk of the stock PCM programming. Replacing your stock TB with a 62mm unit would be a good start; you could even go for the Flometrics 66mm or 68mm unit and enlarge the plenum inlet opening to match.
Are you sure your injectors are only 21lb'ers? I would have expected at least 24's on a HO stroker. Even Hesco recommend at least 10% larger injectors than stock.
Click to expand...
Yeah. I think I'll probably go for a 66mm TB and new intake tube before I try anything else.
The accel injectors are the 21 lb'ers. I put them in myself and they have the 21 clearly marked on them.

Thanks for the input on the PCM programming "quirk". I wonder if that's the case.

Any other ideas anyone?

K
 
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