o2s. low. wide band high....

[shmed]

well heres. some info..
freshly rebuild 109 roller cam roller rockers, 212. cam I believe, hot. wired fuel pump, tt 5.7 chip.
razor alky
ok. so. found a header crack had it welded up, resealed everything,
fired it up an o2. was in the 100s. steady an the Wideband went beyond its reading ability an shut off..
ok.
new o2 sensor reset ecm
tried again same thing.

fuel press at 40 line off. but can smell the fuel while idling
any ideas. what I can try??
thanks

 

[blacknight80]

My car did this with a bad maf. What's your maf reading at idle?

Sent from my SM-G930W8 using Tapatalk

 

[shmed]

6

 

[TurboBob]

low o2 is lean, is the wideband lean?

does this cold / hot / driving / idling ?

post pics of the maf, engine, etc.

Bob

 

[SCOOBY DOO]

What's your BLM's at idle...in Park...with the engine warmed up.

 

[shmed]

A few pics

 

[shmed]

ok. heres. warmed up to 170
o2. 100. 118. 90
Wideband only goes to 17. just reads ---
maf. 6
lv8. 46
volt 13.6
int 128
blm 130
air temp 100
rpm 800
tps 46
iac 40
o2 cc 78
spark 71
open loop

using a new Bosch os sensor
vac reading is around 8. it dropped from 14. once I opened the dump...

 

[earlbrown]

Your INTs and BLMs are happy (IAC is way high but doesn't matter in this exercise) You're open loop so the ECM isn't using O2 feedback to adjust stuff.


That being said if you have a stock or stock type MAF, it's crap. Period. Trying to tune around it is an exercise that can (and will) cost rebuild which is way more moneys than a Translator and good MAF.

The other thing is that Bosch sensor. There is a very specific procedure to using one of those without making your car run bad.....

1) unscrew the sensor
2) Go to your back porch and throw that sensor as far as you can.
3) Walk out to the sensor, pick it up and throw it again.

Use ONLY a Delco, or better yet, a Denso unit. A flaky O2 (which is the Bosch all day long) is a recipe for wanting to put a 350 with a carb in your car. They really are that bad. That same list above works with parts store replacement MAFs.

 

[Grand_87_national]

1) unscrew the sensor
2) Go to your back porch and throw that sensor as far as you can.
3) Walk out to the sensor, pick it up and throw it again.

Lol.

 

[Gene Van Horn]

TPS is also a little off, should be set at .42.

 

[shmed]

thanks for the tips guys much appreciated.
took care of the high iac
changed o2 to a denso
Found the culprit.... a really nice shiny. aluminum ear block off plate... Hugh vac leak.... changed to a crude steel piece made in garage. and all sealed up....