is your gas tank air locking? this is what is sounds like. Loosen your gas cap and go take a drive. Sounds like you are loosing fuel pressure. After the cap you should check the fuel filter, replace it.

If there was some big pieces of dirt in the fuel tank and it move around it could also cause this problem. When the pieces move around they get caught into the fuel line and the sucking from the pump will hold the piece on the collector hose. When the vehicle stops and sits for 20 minutes then the dirt drops back into the tank.

1. gas cap
2. fuel filter
3. dirt in tank

Fire and fuel and it sounds to me like its fuel. when the fire goes it normally goes.....

 thought about that today as well  so i dropped the tank , replaced the FP and screen , filter .  cap is venting proper and the canister line is clear and the tank is spotless
 checking spark when she dies and there is none . but after  20- 30 minutes , the spark comes back very light  but enough to start it . then if checked once running , i find the spark heavy . im thinking something is over heating  

 i have a new TBelt, new plugs , new wires , new cap , new rotor .
 the tach also doesnt just settle like  if the engen dies  from lack of fuel . it pegs to 0

the tach also doesnt just settle like  if the engen dies  from lack of fuel . it pegs to 0

Sounds like a temperature related short in the ignition system if the tach is pegging to zero.  When the engine stops under normal circumstances, power is cut to the tach and it just drifts to 0 on it's on, but if it's slamming to zero something is pulling it down, which really should happen without some sort of polarity reversal in the tach signal. 

ya , thats what im thinking to brent .
 if i pull the coil wire , the engine dies and the tach settles down .
 but with this , it drops to 0 instantly .

 i can duplicate this same thing  by  un plugging what i think is the noise filter  or pulling the  connection to the power block that mounted  on the bracket with the  coil . doing eather  recreates the issue . the engine dies , tack instantly goes 0  and the engine will not start without plugging them back in .
 im thinking , it must be one of these to .

 my exsperiance with coils is they dont fuctuate . eather they are bad or they arnt . if they give off weak spark , its always weak ?
 i dont know , im kinda dumbfounded here as  it was running great  tell i changed the gass filter , wires , cap and rotor  and put the lucas in the tank to clean the injectors .

 the PO had just put in  new platnum plugs . i found them not to be gapped as he had them at .040 so i re gapped them to .028
 other then that , nothing has change

have you checked the engine ground wires? Mine broke a while back and it caused a bunch of issues that would normally not have done anything at all. Turned the lights on and the engine dies....weird things...I hate elecrtical problems.....

 ya i did . first thing .  today i finaly got  it to throw a code 42 . so we will see if changing out the sensor fix's the issue