MSD Atomic EFI on '79 K30 in Cali

[Apache'71]

HELP PLEASE... Just bought (and maybe need to return) a complete MSD Atomic EFI kit with the return system, new '87 tank and sending unit to install in my '79 K30 that resides in California and currently passes smog.

After opening the MSD box and reading the Addendum for the first time, noticed that it says the Atomic will NOT work if you have Air Injection into the Exhaust system. Which my truck does.

After calling MSD and confirming twice with two different people that the system will indeed NOT work with my truck I am pissed that all indications were that this system is complianT for CARB for '87 and older GM vehicles to maintain smog/CARB compliances. It's also my understanding that many (maybe nearly all but certainly that would be an incorrect statement) had air injections system unless it was TBI which I believe was only the latest models. Wouldn't that essentially mean that the Atomic, even-though it's CARB certified, won't really work for nearly any application since most had air Injection?

I really want to make this work despite MSD misleading me up until reading the Addendum, so what are my options?

Here's how I see it:
1. Return everything and carry on life with the carburetor
2. Install it and confirm it doesn't work cause the O2 sensor will be reading lean and dump more fuel maybe the truck run terrible and waste fuel
3. Try to disable the Air Injection System (or some portion) so it looks correct and passes visual inspection but doesn't actually pump air into the exhaust manifolds. But then will it not pass particulate readings...maybe, maybe not...?
3a. Block off one exhaust manifold side by deliberately clogging the air supply tube, install the O2 sensor downstream of this manifold to provide correct O2 readings, and maintain air injection in the other manifold to provide some benefit for reducing the emission to hopefully pass both visual inspection and particulate readings

Any other thoughts or suggestions?

[sweetk30]

it will prob run better on the efi out the tail pipe if they sniff it .

do they give you a carb sticker for the core support ? and does it say anywere not for air systems on the sticker ? does the inspection place know to check its limits ?

otherwise i say pull the pump apart remove the viens off it and re assemble . then take and plug the big air hose inside and reinstall it and play stupid .

its all hooked up and spinning it must be working its clean out the tail pipe .

and why the $$$ msd stuff ? holly snipper or fitech .

[Apache'71]

Thank you all for the responses:

Originally Posted by sweetk30

do they give you a carb sticker for the core support ? YES and does it say anywere not for air systems on the sticker ? NOPE does the inspection place know to check its limits ? NOT SURE

otherwise i say pull the pump apart remove the viens off it and re assemble . then take and plug the big air hose inside and reinstall it and play stupid . CAN THIS BE DONE WITHOUT DAMAGING IT? IN OTHER WORDS, COULD I RETURN IT BACK TO OPERATIONAL IF I REMOVED THE VEINS AND WANTED TO REINSTALL THEM LATER IF THINGS DIDN'T WORK OUT. I AM ASSUMING I CAN JUST REMOVE THE VIENS AS AN ASSEMBLY LIKE A FAN BLADE, IMPELLER, ETC.?

[Tiger Joe]

I’d go with 3. Blockin the AIR tubes and using the fuel injection should yield a cleaner running truck so I wouldn’t see an issue passing smog

[chris989]

Can you contact the air quality board (not sure what you call it in CA).

Where i live, If you advance the technology you canhave it approved and signed off. Considering the MSD fuel injection is most likely superior than your old stuff. Maybe they will approve the MSD out of the box and get rid of the extra OEM stuff.

[Apache'71]

Originally Posted by chris989

Where i live, If you advance the technology you canhave it approved and signed off. Considering the MSD fuel injection is most likely superior than your old stuff. Maybe they will approve the MSD out of the box and get rid of the extra OEM stuff.

I WISH this was an option in California!

[donw1986]

I put one in my 86, with air injection, works great, and passed smog no problems,do not know how it will run with out air injection i installed the o2 sensor past the y in exhaust

[donw1986]

Forgot to mention I live in California to and Pass California smog

[Apache'71]

Originally Posted by donw1986

I put one in my 86, with air injection, works great, and passed smog no problems,do not know how it will run with out air injection i installed the o2 sensor past the y in exhaust

Thanks, Don. Does your injection go into the exhaust manifolds or directly into the cylinder heads? Was your truck TBI from the factory or carbureted?

When I challenged the guy on the phone at MSD questioning why then does the ECU have a setting for Air Pump Equipped: YES/NO, he said this is for when the air injection is after the O2 sensor but before the catalytic converter(s). Uh? Did that even exist on a '75-'87 GM motor? Maybe a TBI equipped model...

[donw1986]

Okay my 86 came with a Rochester feedback carburetor with a dual capacity pump my computer controls the spark timing EST so I do not have vacuum advance I had to also buy the MSD throttle position sensor to make this work cuz I do have a check engine light also the air injection has a diverter valve that diverts air between the exhaust and the intake the air injection goes into the exhaust manifold before the O2 sensor I mounted the MSD O2 sensor past where the y- pipe connects

[donw1986]

Yeah I've never heard of where the air injection connection between the O2 sensor and the catalytic converter

[Apache'71]

Originally Posted by donw1986

Okay my 86 came with a Rochester feedback carburetor with a dual capacity pump my computer controls the spark timing EST so I do not have vacuum advance I had to also buy the MSD throttle position sensor to make this work cuz I do have a check engine light also the air injection has a diverter valve that diverts air between the exhaust and the intake the air injection goes into the exhaust manifold before the O2 sensor I mounted the MSD O2 sensor past where the y- pipe connects

So here's the exact words from the MSD Addendum:

AIR PUMP
"Important: If your AIR system only puts air into the exhaust
manifolds, the Atomic system CANNOT be installed. The fresh air
being introduced to the exhaust will cause false readings to the
WB02 sensor.
If your vehicle is equipped with an air pump, close attention must
be paid to the air injection lines. GM used multiple types of air
injection control from the 1960's to the 1980's. All of the systems
used a belt driven air pump that delivers clean air into the exhaust system. Some of these systems used
a diverter valve to change where the air pump sent fresh air. Early systems with a diverter valve used a
thermostatic control valve (TCV) that diverted the air to the converter at 160°F coolant temperature. In
later years, the TCV was replaced by an ECU, which did the same job. During the initial setup of the Atomic, there is a selection for ‘Air
Pump Equipped’ (Figure 2). This must be answered to ‘Yes’ if your
vehicle is equipped with an air pump (the default is ‘No’). This will
make the closed loop function of the Atomic turn on at a higher
temperature to ensure that the diverter valve has switched and is
sending air to the converter. This way, the WB02 will receive the
true values of the exhaust gasses for the correct operation of the
Atomic’s self-learning and target air-fuel ratio."

So it sounds like your air injection has both exhaust manifold injection AND the intake manifold from what you described? Mine only goes into the exhaust so maybe this confirms how my truck won't work, but yours will based on what I am reading above because it also goes into the intake.

...But then it carries on with a butch of business about TCV valves and diverter valves, etc. which my system has a diverter and a TRV valve (not TCV), it's just that the diverter simply diverts the air to atmosphere instead of the intake manifold like yours I guess...

Above it says the TCV diverts the air to the "converter". Any idea what the " converter" is?

How do you read the above from the MSD Addendum? Am I out of luck with my year truck and configuration?

[Apache'71]

Oh, and the guy at MSD said the Atomic system won't work on ANY vehicle with an Air Injection System that injects air before the O2 sensor. So if that's the case, it shouldn't work on your '86 either, and make the O2 sensor read lean.

[donw1986]

Yeah that sound like a option however not sure what this diagram is of, i do not have any lines running to the catyletic converter, my air system is pumped in one tube on each side of the engine into the exhaust manifolds

[donw1986]

The silver tube is my air injection into the exhaust manifold one on each side and the othe is just a rubber hose from the diverter to the aircleaner there is no tube to my converter

[Apache'71]

Originally Posted by donw1986

The silver tube is my air injection into the exhaust manifold one on each side and the othe is just a rubber hose from the diverter to the aircleaner there is no tube to my converter

Thanks, Don. You've giving me enough convidence that if it works for your rig, it should work for mine. I am going to go ahead with the install w/out modifying the AIR system to start and see how it runs...

Will update the thread with results. Fingers crossed...

[donw1986]

Cool let me know how it turns out

[Apache'71]

Originally Posted by donw1986

Cool let me know how it turns out

Don, any chance you still have this sticker on your air cleaner:

[donw1986]

I have this on my radiator support

[Apache'71]

Originally Posted by donw1986

I have this on my radiator support

Don,

I finally getting to this install. Got the '87 tank in with an '87 sending unit. Installed the MSD fuel pump in the tank and wired it up. Have the supply and return fuel lines loosely run and terminated at the tank. Have the MSD Power Module installed on the firewall and wires run and ready for final termination. Have the O2 bung installed and ready to received the O2 sensor. Still need to install the temp sensor.

I took off the carburetor today (should have done that a while ago, but wanted to delay it as long as possible so I could still drive the truck while utilizing the other stock tank and mechanical fuel pump) and found out I have the spread bore intake manifold instead of a square bore.

I plan on buying the Edelbrock 2696 adapter to rectify this. Did you have this same issue?

Also, does your truck have an EGR valve? If so, how did you maintain that with the new TBI throttle body? [See last picture] . If not, any ideas on how to maintain this for SMOG?

Thanks,

Eric

[Apache'71]

Never mind regarding the EGR valve. Got that mixed up with something else.

My truck doesn't have an EGR valve (probably cause it's a K30)!

One less thing to worry about...

[donw1986]

Yes used edelbrock adapter on intake and yes have an egr and yours should be basicly same it will fit with the adapter, at least it did on mine if that is what your were asking

[Apache'71]

Thought I'd add an update for anybody following or who may be thinking of doing this to a rig requiring CARB compliance.

I got everything installed about two weeks ago and it fired up on the first try! It ran great (despite me plumbing the fuel pressure regulator backwards)! I re-plumbed the regulator, revisited all the MSD settings and can't believe how well it's running. It fires up nearly instantly, it idles pretty well (better than before but I think I could further improve it if I was controlling timing), and the throttle response is almost like a new, ok maybe newer, rig. I could never break the rear tires loose before but now I have to be careful to keep from doing it. There must be at least a 20hp increase on the bottom and mid end.

I have a more noticeable knocking sound (valves?) at low rpms in 2nd gear under load and a slight backfire when coasting in gear when cold and warm, but these issues were present before the Atomic install. The engine probably has some bad valve guides (blue smoke on startup) and could probably use a valve adjustment I suppose. Maybe the vacuum advance on the distributor is defective too. All things to run down in time...

The factory air injection system is still installed on the rig and to the best of my knowledge is functional, but it doesn't seem to be throwing off the O2 sensor as MSD told me it would. Probably the only thing that could pose a problem for emission re-inspection is the fact that the old carb had a TRC actuator mounted to it and there is no provision or way to remount it to the MSD to my knowledge. I just left the vacuum valve that's mounted on the manifold there and capped off the vacuum line since there is no actuator anyways. I guess I'll cross that bridge in two years when it's up for re-inspection...

The only things left to do is to remove, cap off or just ignore the old hard fuel line along the frame rail, remove the mechanical fuel pump and blank off and figure out why my fuel gauge isn't working now after installing the new sending unit.

Hopefully this will give some other folks on the fence a little more piece of mind where CARB compliance needs to be maintained.

Let me know if anyone wants more details on parts used, install, MSD settings, etc.

[buffydores]

God bless anyone who has to deal with CARB. I'm so thankful I don't live in California. Wonderful place to visit though.

[donw1986]

You can maintain the dual tanks, i did , there are 2 types of tank switching valves the earlier years it wont work not sure exactly what year they changed them but the valve in my 86 is rated for 65 psi, works fine, you will need to change the switch on dash to an 87, the 87s came with factory throttle body so the switch appears the same but keeps power running through it to power the fuel pump i installed a pump in each tank, when you flip the tank switch it reroutes the power to the punp on the tank you select