Ok, before you all get the chance ... IDIOT!

Ok, now that everyone, including me, knows I'm an idiot, let me ask my question. When looking at my bin file ($8D defn file, 350 SD-TPI engine), I find a flag called "dual or single air valve", which is the same in both winbin and tunercat. What is that referring to? The butterfly in the TB is what I thought, but why would the ecm need to know if we have 2 when they both open at the same time. I also thought maybe IAC. But I'm having some problems with my fans, and I notice that they both come on at the same time, so I'm wondering if that referrs, for some insane reason, to the fans? I downloaded the bin, so I'm not sure if the stock ecm is set to 1 or 2 valves.

 

From what I can tell it is for the air pump.

RBob.

 

Sounds like AIR injection system valves. I don't understand though, I've never seen one with just one valve (or maybe I just haven't paid that much attention!)

One of the valves is to direct the air upstream (manifolds, or headers, bevore the O2) in order to help warm up the O2 or to the cat to help it burn the excess HC's. The other valve, I'm going on memory here, but I think it's to divert the air to the atmosphere on decel to prevent backfiring in the exhaust that you would have otherwise.

Hope this helps a bit!

 

That would be the selection between a dual port and divert (dump) air injection solenoid valve pair, or a single, diverter air injection solenoid valve.

BTW - I'm an idiot, too...

 

So with the single is there no AIR to the manifolds, or headers? The double would have both tubes in the headers and one to the cat?

That's what I'm getting from this!

I'm gonna be needing this info for when I get my TPI setup on my car, so that I get everything right the first time!!! (Yeah, right, like that EVER happens! LOL)

 

Anyone figure out what this is for sure?

I'm running the $6e code and have been looking for a way to disable the AIR system on my car in the prom through Tunerpro (That's about as hacked as I have gotten).

There are no constants or tables in the 6Ev011 def to control the air. That flag is the closest I see.

I have removed the cat and I am about to remove the AIR also. Thought I'd do it right and do it in the chip too.

 

Sorry to bring this one back from the dead, but I have the same question.

I guess I'm an IDIOT, too.

I kept my 383 SuperRam emissions legal, and kept my air valve which has 3 outputs: one to the headers at the exhaust ports, one port going to the dual cats, and one on top for the "diverting to atmosphere".

So, is this considered a "dual air valve" or a "single air valve" prom-wise? I too am running a $8D speed density setup.

- Vern

 

"dual air valve"

RBob.

 

THANKS! That's I suspected but every bin I've looked at, even the replacement I ordered from GM to have a batter (350) limp mode home for my 91, didn't have "dual" selected.

I'll change it and give it a try later this week. Again, Thanks!

- Vern

 

RBob, I am thinking that this "single vs dual" is probably for one of the other types of vehicles that use the 7730 ECM. I think GM brought over a lot of "common switches and constants" between the variety of calibrations that use the 7730 and just didn't bother "cleaning up" the code.

I say this as an "old crusty programmer" where I would often use a program I had previosuly created to create a "new version" and often left a lot of the older code in it. This was because it never hurt anything by leaving it there, space (memory) was not a concern and I could sometimes cause more headaches trying to "remove it/clean it", because some "unknown" variable may have referenced the code and now I end up having to undertake a major rewrite when I just wanted a "similar but different version". Thus it was simpler to just leave it in tact and just use a "switch" to make if function as I wanted.

Given GM production schedules and least costly method to do something, I suspect there programmers did the same thing.

BTW, I have a buddy who is using the air diverter to move air to the cat, but doesn't have the air go to the exhaust tubes (he doesn't have air tubes on his headers).

EDIT: It's been a long time since I looked at this in detail. We did nothing to the setting as his was a MAF car and there was no "SINGLE/DUAL" on his calibrations (that we are aware of). But the lack of "air tubes" (and now he has removed the air diverter entirely) did not affect the the tune. We did disable the air diverter now entirely.

 

was his dual to start with?

 

That's strange. I checked several to double check my thoughts and they all had dual set. Location $017,b2, 1 = DUAL AIR VALVE/ 0 = SINGLE.

RBob.

 

That's what I was looking for, Thanks again, RBob!!!!

:hail: :hail: :hail:

 

There is no "Dual vs single" switch for his 6E MAF calibration. I made a note on it above. For SD cars, the stock AUJP bin has it set to "single" since there is only 1 air diverter...it either works or it doesn't.

You need to address this to a specific bin.

 

I thought I did to start with (SD and $8D in a 91 Formula with dual cats), if I wasn't clear about that - SORRY!

 

I looked at a number of the $8D bins with TunerCat and all had the switch (including my original AUJP) set to "Single".

 

Note: This message is more for RBob, as this mesage may appear as gibberish to others.

RBob, I just checked the "TDF" at TunerCat and they are using a "bit mask" of Hex "40", which is not b2, but b6. I double checked the 8D hack and you are right, according to the hack, it is b2 that should be set on. So it may be TunerCat's "mask" for the the "Single/Dual" that may be incorrect.

When I modify TunerCat's "mask" for the "Single/Dual" constant to Hex "04" instead of Hex "40", the Dual Switch is in deed on for AUJP.

I will ask TunerCat to double check the "Air Diverter Single/Dual" switch in their TDF as all the documentation confirms what you are saying.

 

Glenn - did you get any feedback from TC yet?

I just looked at some of my bins with my TunerPro RT and it looks like the dual option is checked on the same bins TC shows it not being checked.....