1986 IROC with ZZ4 350

**S10LS** · 10-13-2013

I just typed a long reply and it got deleted,not happy. thanks gearheadefi. Now Put the DAM wideband where it belongs. Stop trying to chase goofy injector data theories. Injector data is a small small part of your problem. Surprised these guys here haven't figured it out for you. This problem is not that complicated. Put the wideband in the PROPER location. Before a hollowed out cat is not the PROPER location. AGAIN what are the narrowband voltages telling you? If you knew how to read or post logged data you would see what the problem is. Good luck

**S10LS** · 10-13-2013

never mind

**S10LS** · 10-13-2013

Originally Posted by ZEDRATED

So any reason why on idle my WBO2 sensor keeps going max lean?
Could it possible be an ECM problem? The NBO2 sensor is brand new and continuity from the sensor to the computer is good?

Ok the narrowband is brand new, that's a relief. Now WHAT is it reading?? Who cares what the wideband is reading? Why are you hung up on the wideband reading?

**S10LS** · 10-13-2013

http://www.gearhead-efi.com/Fuel-Inj...1&d=1380313658. This picture you posted of the narrowband in the header. PUT the wideband in the other header. Doesn't help that your narrowband is non heated I missed that part. Your problem is not injector data. Your narrowband does not like the overlap of the cam and being a cold sensor. It shows that when you put it in open loop it runs ok. That means your ve tables and injector data is close. When it goes to closed loop the narrowband goes crazy and the fueling goes downhill.

**S10LS** · 10-13-2013

Originally Posted by Hog

Exhaust flow over the sensor. WB's dont do the greatest at idle.

peace
Hog

This was your answer. But actually the narrowband with a cam and non heated don't do well at idle and cause the wideband readings to go screwy.

**ony** · 10-13-2013

zed rated try a heated o2 sensor, I put 1 in my old truck and it changed a lot, if it is heasetating it is more than likely transestion from idle to at lest half throttle [pump shot with a 7747 ecm] I don't know about the ecm bins in you vehicle try changing the injetor off set like eagle mark said.

**Six_Shooter** · 10-13-2013

What's with this idea that WBO2s don't work well at idle?

Using incorrect injector offsets can cause large problems especially at idle, so I would not recommend ignoring them...

**S10LS** · 10-13-2013

Originally Posted by Six_Shooter

What's with this idea that WBO2s don't work well at idle? Location and heat with his application.

Using incorrect injector offsets can cause large problems especially at idle, so I would not recommend ignoring them...

People have tuned injectors with out all the data for years and have not had issues. Not saying its right or lookin to argue but imo its not his problem.

**S10LS** · 10-13-2013

o/p your stock narrowband was designed to be used with stock exhaust manifolds and a cat. You have neither. Your narrowband is not heated. Neither type of 02 sensors narrow and wide work well with a cam with some overlap at idle with subobtimal conditions you are using them in. You have to help them work well. How does it run off idle and cruising and wot? Simple really why in open loop does it run different? The narrowband is going crazy, swinging up and down, overshooting. But in open loop there is no correction from the narrowband running off the ve table, which must be close. So how does injector offset data work in open loop and not closed loop?

**Six_Shooter** · 10-13-2013

Originally Posted by S10LS

People have tuned injectors with out all the data for years and have not had issues. Not saying its right or lookin to argue but imo its not his problem.

If you had been around for his other thread you would see what has been going on with this car, and in my fairly extensive experience in tuning MPFI systems the proper injector offsets are needed or at least offsets that are close.

I've tuned without them and once I swapped to proper offsets and then RE-TUNED for them the engines ran so much better than without.

So please stop posting this misleading information about how his O2 sensor was not designed for this or that, it is inaccurate and only serves to confuse the situation.

An O2 sensor was not designed to work in any specific situation or with other components, they are simply designed to create a voltage based on how much fuel is left in the exhaust that it happens to be sampling from. The only part I agree with is that the headers will cause an issue with a non heated O2, but is simply due to heat, and not because there are any other parts needed. Headers will simply move the O2 sensor away from the exhaust port which allows the exhaust to cool more than with manifolds and can cause the O2 sensor to stop working correctly, at which point if the ECM detects this it will drop out of closed loop.

**S10LS** · 10-13-2013

You sir are a fool plain and simple. You have mislead him. Your fairly extensive tuning career has not helped this guy one bit. Get your head out of your rear. Another lame ass forum goodbye and goodluck.

**Six_Shooter** · 10-13-2013

Originally Posted by S10LS

You sir are a fool plain and simple. You have mislead him. Your fairly extensive tuning career has not helped this guy one bit. Get your head out of your rear. Another lame ass forum goodbye and goodluck.

Have fun with your other forums. :wave:

**ZEDRATED** · 10-14-2013

Now, now, let's all get along Boys lol.
I see everyone's point here, S10LS does have a good one, if the offsets were way off then it wouldn't run close to stoich in open loop either. I am running around 13-13.5:1 in open loop, don't forget that this is still with the stock AUM bin. Just first trying to figure out this O2 sensor problem. I disagree with puting the WBO2 sensor in the other header and prefer it where it is because it is collectiing data after the y pipe meets, where else should it be??? I think I have it in the right spot.
As for the nbo2 sensor, I believe it is working fine off idle, with the stock AUM bin at cruise in open loop it is running really rich, like 11-12:1 and when I use a bin working in closed loop it runs about 14.9-15.3 which seems leaner than it should be and at 43.5psi it was running really lean at cruise speeds like over 16:1 so after boosting FP up to about 48psi it is now better. With my set up making about 350-375 HP with a perfect tune, should I not need to boost up fuel pressure for the 24lb injectors from 43.5- let's say about 48????

**ZEDRATED** · 10-14-2013

And I don't believe air is flowing over the WBO2 at idle because in open loop it is reading properly on idle.
Six_shooter, how do I convert this sensor to a heated O2 sensor? Might be the best solution???

**ony** · 10-15-2013

zed rated what I was talking about an I assume hog was is the exhaust[ airflow] doesn't move enough volume at idle to get a precise reading as to going 1500 rpms. 3 wire o2 sensor 1993-95 chevy pickup black wire is signal wire 2 white wires are + an- hooked up so no voltage when key is off. I bought 1 the other day and found a horness at parts plus 7.50 for the connector, am auto part o2 sensor 23.00 shipped . I was talking about the nbo2 not your wide band.