cxxm

To anyone who can help:

I am trying to figure out if air is sent to the catalytic converter during normal driving in closed loop?

I have a 1984 TA, at this moment, that is all stock with the computer controlled carb and emission parts. My problem is understanding the air diverter and switching valves. Both valves run off engine vacuum, but also have solenoids controlled by the ECM that control when the vacuum is allowed to open the valves.

The only times I see air sent to the ports or the converter are at warm up (open) loop. I know this, because I have pulled off the lines to check and attached LED lights to the solenoids to see when the ECM grounds them. I have never seen the lights come on in closed loop at idle or running down the road.

In an old post from 2003, response #30 below; it seems to be supporting that no air goes to the converter after warm up.

https://www.thirdgen.org/forums/diy-...-pump-air.html

“That's the problem. That statement is not entirely true. I have tons of datalogs with AIR being injected during normal driving. This is AIR being injected at the manifolds ... which DOES affect the O2 sensor. Furthermore, this happens A LOT. This is not just a simple inject at the manifolds every now and then. It happens a lot. On the other hand, I think your statement is true for AIR being injected at the Catalytic Converter. None of my scans show AIR being injected at the converter during normal driving after warmup.”



The folks at Magnaflow told me the following in response to my questions about how much air should converter get going down the road and what if you were to plumb the smog pump directly to the cat:

“Air goes to the converter in a steady stream except when interrupted by WOT, Decel or an ECM in open loop. The amount of air does not affect the converter unless we have an engine that is running too rich. The extra fuel combined with all that oxygen can have the effect of creating a small furnace. Air alone has no negative affect other than lowering NOx reduction in a Three Way Cat (TWC)” - Magnaflow

What I do not understand is what ECM is being spoken about in the post. Nor do I understand where my ECM fits in with all the other ECMs. I have seen bin files posted on ECM’s, but not sure if my ECM has been decoded or how it relates to the others.

My ECM is a 1226455 (16035451, CJZ, 865451, 47553398), L69 4BBL 305, VIN G. Also, my ECM seems to be working fine. No codes or any other strange conditions.

I have another ECM out of a 1984 Monte Carlo, 1226455 (16027981, BDX, 867981, 42604896) VIN H (LG4 4BBL 305)

Does anyone have any idea what the CJZ or BDX mean?
Can I use either one of these ECM’s in my car or are they different?
How do I figure out what PROM is in these ECM’s?

There are so many posts out there; I am not sure where I should begin. I started reading the https://www.thirdgen.org/forums/diy-...uide-book.html post, but have not been able to answer my questions above.

Thank you…

EagleMark

I've always wondered what the routine of airpump was when injected before an O2 sensor, just does not seem right, but reading what you posted about only during warmup and open loop seems logical.

As for the 3 letters that is your BCC code (Broad Cast Code) of the chip in the ECM. You can look them up here:
http://www.gearhead-efi.com/BCCFind/

cxxm

EagleMark thanks for the great info.

So am I correct to conclude that there are no bin files, ADX or XDF information for the BDX or CJZ PROM?

I was hoping to obtain this information to conclusively conclude if no air is sent to the converter during closed loop. I know later model firebirds use an air diverter/switching valves without engine vacuum.

Not sure how different the code would be for the air divert/switching between the CCC and fuel injected Firebirds?

Lastly, what would I do if my PROM went bad and I could not find a replacement in the salvage yard? Am I correct that the BDX prom would not work for my car?

I see that BDX is NA5 FEDERAL REQUIREMENTS and CJZ is NB2 CALIFORNIA REQUIREMENTS, which has to deal with emission parts. Not sure yet what emissions parts are different between a Federal and California car.

Here is the following information on top of the proms. Not sure what any of it means.

Delco
5838
CJZ
Delco 519k 8424
4541 06630
CE1090N

Delco
7835
BDX
Delco 519k 8347
3074 06630
CE 1086

BCC information:

BCC= CJZ 5838
Scan id= 5451
Part number= 16035837
Release date= 05/19/83
Engine size= 5.0
Trans Type= Manual trans
ECM/PCM: ECM #01226455
Possibly used in: CAMARO SPORT COUPE, CAMARO BERLINETTA, FIREBIRD, FIREBIRD TRANS AM, FIREBIRD SE
Options: With L69 5.0L GAS 8 CYL 4BBL HO, With MK6 MAN 5 SPD BORG WARNER 2.95 1ST O/D, With NB2 CALIFORNIA REQUIREMENTS

BCC= BDX 7835
Scan id= 7981
Part number= 16037834
Release date= 05/19/83
Engine size= 7.8
Trans Type= Auto trans
ECM/PCM: ECM #01226455
Possibly used in: MONTE CARLO, GRAND PRIX, GRAND PRIX LE, BONNEVILLE, GRAND PRIX BROUGHAM, BONNEVILLE BROUGHAM, BONNEVILLE LE, REGAL, REGAL T-TYPE
Options: With GH2 AXLE, REAR, 2.29 RATIO, With GU1 AXLE, REAR, 2.41 RATIO, With LG4 5.0L GAS 8 CYL 4BBL, With M31 AUTO THM 250 CONV CLUTCH, With NA5 FEDERAL REQUIREMENTS

cxxm

BDX pics...

EagleMark

No ADX or XDF I know of for CCC cars, not a lot to tune there. There was just a recent thread about finding a blank chip for them and then no burner available, then again not much to tune?

I don't think I've ever seen a chip go bad or even heard of one going bad without human interference, so if you need a ECM just swap your chip in.

Or convert it to TBI?

DENN_SHAH

iTrader: (1)

the factory chips do on occasion go bad, but it is very rare.
i don't think i've seen more than 10 chips that were actually bad in over 30 years of being a professional wrench unless someone have messed with them. new chips were sold with ECM replacement mainly because of the OEM updates to the bin file on/in the chip or because of some driveability problem related to an update.
most chips get damaged during removal or installation during ECM replacement.
of course the older they get, the more likely they may go bad.

only during open loop idle or open loop cruise is AIR sent to the manifolds, its done to help heat the cats during warmup.
AIR should be sent to the cats during closed loop cruise. some vehicles do inject AIR during closed loop idle.
if any AIR is injected into the exhaust during decel, then there will be 1 or more "backfires" in the exhaust during coast down.

it seems like Fast355 had mentioned one time a site that dealt with chip burning for the 3-C systems.

TunedPort350

cxxm

Thank you for the information. My 1984 service manual is similar to this 1988 information, but this has a few more details of incorrect operations that mine does not have. Also, my air valves runs on engine vacuum and the solenoids compared to the 1988 solenoid activated air valves.

With all the conditions that these air valves are allowed to run under my guess is that they must just be sending puffs of air to the converter in closed loop. Maybe, like a person's breathing.