Maybe replace all your fuel filters. You have enough pressure while it is running but if your filters are bad that pressure will drop off right as it dies and I doubt you are watching your pressure gauge in the engine compartment as it dies.

 

No I am not watching the gauge as it dies...I am watching the gauge as I do full power accelerations and fuel pressure stays above 3lbs thats how its always been and Ive never had problems until fuel pressures reaches 0lbs during hard accel then it falls on its face a few seconds after reaching 0lbs as expected....(that was a long time ago)

however you may indeed be on to something....I run a solenoid fuel cutoff...the system is powered by 12v and is naturally closed...I removed the solenoid today because I suspected just maybe it could be failing...so far no problems but not enough time to test for sure yet.

The solenoid is after the fuel pressure gauge so fuel pressure will not indicate if the solenoid is open or closed.

Thanks

-Gun

 

Well first, O2 sensors don't actually read oxygen content in the exhaust. Lean readings can come from lean, rich, too much timing....a complete ignition misfire could also generate a lean reading(but not because of O2 content in the exhaust).

It could be ignition cutting out generating a misfire that reads lean, could be ignition problem causing timing to fluctuate to excessive advance and creating a ton of NOx giving a false lean. Could also be crap in the idle circuit in the carb.

What carb is it? Have you checked all the ignition stuff?

 

Well go drive it sucka!!

 

Okay problem still there its not the fuel cut off solenoid.

Today when the engine died I pulled the boot off the coil and cranked it I got nothing.. I tried to ground a steel pry bar and place it very close to the coil...nothing. In the past lightning would always jump like 3 or 4 inches out of that coil.

I replaced the boot and the car did restart it died a few seconds later...it restared and after a short drive to a parking lot I shut it down and got some MSD docs from the internets (thank you Al Gore!!!) I did the MSD self test.

1) Remove mag pickup from dizzy.
2) remove boot from coil to dizzy on the dizzy side only
3) turn on ignition.
4)place coil boot near ground
5) momentarily jump the green and purple mag pick up wires on the mds box side (dizzy is removed from circuit)

6) when mag pickup leads are jumped and the coil should spit fire to the ground and it did. It made a squeaking sound and spit like 3 to 5 sparks to the ground

Reconnect everything and start car...again wait for it to die and repeat test quickly

Upon retest I got nothing like I wasnt even getting power to the box...

All MSD ground and power from ignition seem to be working. MSD power from battery seems to be working.

after checking all the wires it tested okay...hook everything back up and car starts.

Keeping RPM above 1000 seems to reduce chance of total shutdown.


So....

1) intermittent power to msd
2) MSD box internal failure
3) apparent weak spark from bad coil???? or apparent weak spark secondary to MSD box internal failure.

Im getting closer...

-Gun

 

I know this may sound weird but make sure you are getting a good connection from your battery terminal. Some of those cheesy connectors can god bad on the inside and get a poor connection. sounds like you might have something internally wrong with the msd box. is it grounded well? Is your engine grounded well?

 

IDK, some damn good answers here, but I think I would change out the coil, this will at the least eliminate the coil as suspect.....

 

I was actually planning to replace all connectors....they are tight but look questionable.

The engine is grounded well

 

This is the next step after new connectors...

However...When the self test showed all okay I removed the + lead from the coil to see what would happen...the box its self made a squeaking sound and I got no spark...with the coil connected it makes a squeaking sound from the origin of the spark (kind makes you wonder wtf its doing so the spark makes a squeaking sound and not a pop)

For several reasons this does not rule out a coil I guess it just makes it slightly less likely.

 

I have 6 msd boxes on various motors, in 20 years the only time I had as box go bad was after a loose connection to the battery. It will be intermittently bad then just totally crap out one day.