Clogged up exhaust........rat nest/squirrel nut hide out.
6sally6

I would try fuel filter first, if you haven’t already.

Next I would verify fuel discharge is consistent after the pump.  Since you mentioned a “no change” initially from last year.

Since it’s an Edelbrock, remove top cover and inspect to see if anything obvious, like float problem, varnish build up, or junk in fuel bowl.

Hope this helps.

When something ran fine when parked, and then didn't, I've found its a waste of time to try adjusting things to solve the issue.  Whatever setup you had in the carb, timing, etc. are all proven to work.  The problem was induced by it sitting.  Those settings didn't move on their own.  So step 1 is to put everything back the way it was.

Step 2 is to look at the easy things first.  I'm with Nos681 as the first step would be to replace the fuel filter, and then inspect the bowls in the carb. 
 

I would be looking at fuel delivery.  Filter, internal tank filter and fuel pump.  Stock fuel pumps are cheap and easy to replace. DO NOT  run it without a fuel filter, especially if you might be having related problems.

Next is ignition coil.  Failure mode is they lose power as the engine temperature increases, or as load increases.

If you suspect a head gasket issue, a radiator shop can check to see if the system is holding pressure, and can check for products of combustion in the coolant.

Thanks MS and TKO...

Car is 100% bone stock and original except for the intake and 500cfm Edel...Ignition is stock...

-car has a new Coil installed last summer. 
-pump 3 or 4 summers ago
-another new clear filter ====== the Levels in the Filter show from FULL SOLID to BONE DRY! 

i was thinking the transition from stop to accel, and the Higher RPM hesitation was due to Vapour Lock so we just added a Wood Spacer........results yielded 0.
but that clear filter is telling a good story!  intermittently goes Bone Dry, then can be a solid half full and even FILLED entirely........wtf is going on! 

we ordered a fuel sending unit because he has had the car for 40+ yrs and hasnt changed it, but the inconsistent fuel levels in the filter would mostly point to pump no?  and if so, how can it pump and not pump???

ok but the key issues here are:

ONLY WHEN HOT, Car will very randomly DIE the literal instant you release the brake from a stop and just Touch the Throttle.....it shows very little signs with a very mild rougher idle, but the very instant you touch the throttle it will just die....

second, higher RPM hesitation.......so as each gear goes to change at the higher RPM range (accelerating with half throttle or greater) it hesitates.  as if its starving for fuel.....

clear fuel filter will be FULL to the brim at times, others half and other times bone dry....im assuming these are related, but also not certain
 

From what you're describing above.........your "new" fuel pump is crap....or the sock on the fuel pick up (in the tank) is clogged.
The little glass fuel filter should remain full or near about when the engine is running.
6sal6

M1Mustang69 wrote:

Precisely 6Sally.....Fuel Sending unit/Pickup was first on my list and I just picked one up.....the owner (good friend of mine) has had the car for almost 40yrs and never changed it, so starting with that.......

MS that was next on our list.....New Points and Condenser.......the coil is 1yr old so Im going to assume (dangerous I know) its not that so start with Points and Condenser......

Anyone know of of a product to clean the inside of the Gas Tank?????  CLR? lol
 

Yes, get a new gas tank

Consider what happens when you try to clean it, it doesn't work and you're stuck where you need a new one anyway.  The internet is literally littered with horror stories about gas tank cleaners and sealers.  The ONLY reason to use those products is if you have some rare, or oddball vehicle for which they simply don't make a replacement tank.  If a vehicle has sat for a long time its always good practice to put a new tank in it. 

You can test an ignition coil.  Pretty easy with a multi meter.  I've yet to see one pass those tests and still be bad. 

I would suggest isolating the body hard line and carefully use carb cleaner and compressed air in both directions to see if something is in the line.

Place a rag over the end to catch anything as well as preventing gas spraying all over the place.

Start with low pressure then increase as needed.

Last edited by Nos681 (7/10/2020 5:23 AM)

He has to be made to understand that there is such a thing as false economy.  At this point in my life my time is simply too valuable to waste on a project someone doesn't want to do right.  Its come back to bite me too many times.

Buying a new tank is not frivolous when the existing one is in questionable condition.  I wouldn't waste 5 minutes of my time trying to clean a tank that's readily available and not absurdly expensive.  At this point I barely get time to work on my own stuff, so going down a rabbit hole on someone else's project just isn't worth it to me.  I'm all for helping friends, and even at times complete strangers, but if they aren't going to listen then it begs the question why are they talking to me?  There's all kinds of reasons to help people and that people seek out help.  Be careful you aren't being taken advantage of by a guy crying poorhouse who just doesn't want to do what's required and places no value on your time.  The voice of unfortunate personal experience here. 

I agree and have done all the above. My 67 C10 has a new tank 20 yrs ago and a carter/edelbrock carb, i dont drive it much but because of the newer tank it always starts up and performs as it should. Also it sets all winter with a full tank. the carbs are ease to service and I have replaced a couple accelerator pumps and the rubber fuel lines once buts thats all. On my stang i replaced the tank because it was 50+ years old thats a no brainer.