MSD Atomic EFI on '79 K30 in Cali
 

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?

Re: MSD Atomic EFI on '79 K30 in Cali
 

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 .

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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.

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

Thank you all for the responses:

Re: MSD Atomic EFI on '79 K30 in Cali
 

I WISH this was an option in California!

Re: MSD Atomic EFI on '79 K30 in Cali
 

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...

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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?

Re: MSD Atomic EFI on '79 K30 in Cali
 

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.

Re: MSD Atomic EFI on '79 K30 in Cali
 

Yeah i am not sure about the different types of diverters i just know what i have, the converter they are talking about is the catalytic converter, once atomic is installed you can set whatever target fuel air ratio you want, i left mine at the recommended ratio, when i took it for smog It passed with flying colors my numbers were all really low compared to the allowable numbrrs

Re: MSD Atomic EFI on '79 K30 in Cali
 

Well if yours diverts to the atmosphere, i think it wouldnt be any different than mine as far as it basicly isnt always putting air in the exhaust but im not sure, when i read those instructions i was aiso concerened but took it to mean that they were talking about the divrrter valve not always blowing into exhaust i am not an expert on this i just wanted to get rid of that carburator so i just went on with my install and i am really happy i did, it runs so much better and passed smog, i do live in Los Angeles county, and i think you said you are up near the bay area so i do know that different counties have different numbers and requirements, i had called the smog ref and asked them about this msd kit before my install and the guy i talked to was very interested in seeing this, and told me to install it and bring it to them because allot of small shops are afraid to pass aftermsrket stuff because they dont know about all the different parts, but when i installed it i did take it to my smog guy and he passed it so never went to the state refereree, i had also installed a new catyletic converter too, there is a forum on the msd web site thst could help you too, but i asked a few questions on thete and didnt get very many replies

Re: MSD Atomic EFI on '79 K30 in Cali
 

Thanks for the help, Don. I did read the MSD support forum yesterday and after searching my issue, the only relevant dialogue I found was from you, assuming it's the same Don W.!

Maybe I'll post there too and see if anything pops up...

Here's your AIR diagram when cold and when warm. So it looks like yours diverts to the air cleaner under high RPM to prevent backfiring, but it also looks like it diverts into the catalytic converter after it warms up. So maybe MSD's ECU setting on yours delays reading the O2 sensor until after it warms up, when the air is injected into the catalytic converter and downstream of the O2 sensor.

Unfortunately, mine gets dumped into the exhaust only (except under high RPM/vacuum where it's diverted to atmosphere). Maybe my only hope is the AIR system injects compressed air near enough to the exhaust valves to continue the burning of the normally unburned segment of the exhaust gases and therefor doesn't have that negative of an affect on the O2 sensor.

But after looking at the pump, it does appear I can simply remove the veins to make it appear functional but not actually pump any air as sweetk30 suggested.

Decisions, decisions...

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

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...

Re: MSD Atomic EFI on '79 K30 in Cali
 

Cool let me know how it turns out

Re: MSD Atomic EFI on '79 K30 in Cali
 

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

Re: MSD Atomic EFI on '79 K30 in Cali
 

I have this on my radiator support

Re: MSD Atomic EFI on '79 K30 in Cali
 

Fellow CA resident here. Unless your buddies with the smog guy, it’s never going to pass visual inspection. Your best bet is to return it or register your truck in a smog free county. The Bay Area smog guys will fail your truck for any visual problem.

Re: MSD Atomic EFI on '79 K30 in Cali
 

Call the referee hotline and ask to get a call back, talk to the referee and explain the situation. There is on in Livermore and they should be able to point you in the right direction.

Re: MSD Atomic EFI on '79 K30 in Cali
 

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