Hi All,

This is sort of a strange question. I have an 83 Trans Am that has the stock diverter valve. This car also have TVS's which control the vacuum to the valve. Will this diverter still function if the plug to the computer is removed? I searched but was unable to find anyone asking this question.

Thanks

 

AFAIK no. At least, not ... completely right.

All AIR pump output will go to the catalytic converter at all times. It will never go to the manifolds or be dumped to atmosphere.

 

Thanks for the reply. Thats what I thought the answer would be. I wonder how its possible to pass CA smog with an MSD Atomic EFI setup. They say its legal for cars that came with carbs, but must retain the emissions stuff. How is that possible if the solenoid is computer controlled?

 

Sound so like this is the exception that it is compliant.
Since the diverted valve is cc sounds like the only option is like sofa said run the air to the cat if it's not already that way. If you have air tubes this messes with the o2 signal on gm production they added 1mv to the o2 me value so the ecm wouldn't think your running lean and over compensate.
The diverted would need to be enigerized sw ign to work all the time ground one of the pink/Blk wires the other would be sw ign.

 

Thanks guys. I just called the referee station to get some clarification. I will post what they said when they call back.

 

Got my answer. Had to do some major digging. Ill post it here just in case anyone ever needs it.

CARB Compliant Atomic TBI Installation: The Atomic TBI system has been granted Executive Order
number D-722 which deems it legal to install on 1987 and older GM passenger vehicles and trucks
that were originally equipped with a carburetor and V8 engine. During a CARB Compliant installation,
the factory ECU remains in place to operate the ignition timing and AIR Pump system. In order for
the OE systems to function properly, a TPS signal is required. The outputs of the TPS Module will
provide the correct signals for the factory ECU and is required during any CARB compliant Atomic
TBI installation (see Figure 3).

 

You would think if it's just using tps as a trigger you could use a throttle bracket micro switch to control a relay to operate the diverted valve.

 

I failed to notice at first, but the OP is in CA.

They're going to put the **** probe and full cavity search protocol on that. A Micro switch isn't going to cut it.

Not sure where Atomic TBI fits into all this... unless that's already on the car. But it will need the stock ECM and the stock diverter valve, along with wiring the TPS signal from the new TBI system to the OE ECM, according to the extract posted above. With, of course, the plugs all connected to everything.

 

So how did the non-ECM Canadian diverter valves work?

 

The same as pre-ECM domestic ones...

Very crudely. Originally, they only diverted (the reason for the name) pump output to the atmosphere during sharp spikes in vacuum, corresponding to the throttles slamming shut suddenly, which can cause cyl pressure from the AIR pumping into the exhaust to exceed intake pressure and cause popping back into the carb; to avoid that, the pump output was dumped. Later, a few came with temp switches that also directed air to the manifolds when cold and the cat when hot in addition to the diversion function.