fuel and carb question

[scott123]

I drove the blazer for four plus years with zero mechanical issues. I pulled it a part (body panels only) and painted it inside and out. From there I can't get to the store and back. I am thinking it is because I got a great deal on a Tangier Orange paint that is actually a Ford paint and from there the God's have frowned down upon me.

If the Blazer sits for a couple weeks the bowl is "dry" and the Blazer will not start. I can add fuel to the bowl and it fires right up and will refire everyday as long as it does not sit.

Secondly, yesterday as I am driving at 55-60 after several minutes it feels like it is running out of gas. I can let off the throttle and let the carburetor/fuel 'catch up' and then go back to driving.

It will sit and idle til the cows come home.

I pulled the carburetor off and checked both floats. I replaced the filter. I even replaced the fuel pump. I do not see any evidence of leaks in the line (sucking air/unless it is on top of the tank).

Any thoughts? Ideas? Strip the Ford paint as an offering to the GM Gods?

Scott

[geezer#99]

Pull the eddy carb off and slam dunk it into the nearest dumpster!
Put a quadrajet on it. Or a Holley.

[scott123]

It's Holley/Demon version on it. Floats are good and set. This morning I noticed although it will idle, it seems to be loading up pretty good. It is burning a lot of gas/really rich smelling.

Scott

[kwmech]

Did this backfire at anytime?? Blown power valve?

[Dead Parrot]

Check all the fuel lines for damage or being pinched shut. Maybe one was damaged during the body panel removal/replace.

Same fuel cap? If a new one, maybe it isn't vented where the old one was.

Still have 'winter' gas in it? The winter stuff tends to evaporate quicker.

[chevyguyase]

I don't know what we're working on, but I'll try. If it's a mechanical fuel pump test for 4-5 lbs of fuel pressure but also check for fuel volume it should pump 8 oz of fuel right now. enough to fill your carb bowls in a minute or 2 of cranking. Try drawing fuel at the pump inlet to check for sucking air or collapsed rubber fuel line. I would hold off on scraping the paint off for now.

[Stepside Jim]

I did a paint job on a car years back. The car drove fine before, wouldn't hardly start after the paint job.

The paint and additional work took a little over a year, the filter sock on the end of the pickup tube in the tank had coated over and wouldn't pass gas through.

[TATE228]

I have had a bad mechanical fuel pump cause a similar problem. It would pump just fine but if i let it sit it would not prime until i got the rpms up.

[scott123]

It is raining out today so I will do a deep dive.

1. It has not spit back or back fired so I think the power valve is OK.
2. This is the second fuel pump as I went there first.
3. I changed the inline filter and noting but clean gas passed thru it.
4. It's not winter gas as I'm in NC so we have "top off weather" in the winter LOL
5. It has a new gas tank and the previous owner said new sending unit (can't verify)

I can't see where any gas is leaking from a line.

I'm thinking I will end up dropping the tank to see if a line is cracked or split on the topside of the tank.

Scott

[geezer#99]

So, no eddy carb!
No matter what carb, you need to follow this rule.
Timing first, carb second.
What’s your base timing set at?
What’s idle rpm?

[mattfranklin]

I had a similar issue after parking. I don't drive mine often enough and the pump seems to lose its prime.

1) If I parked nose down on my sloping driveway it seems to be better.
2) If I pop off a fuel hose at the pump and dump some fuel in there before hand it seems to start and run ok.
3) Also, one time I took a big breath and blew hard into the fuel filler (I have unusually large lungs) -- once you've exhausted your air, quickly turn away and move your body away otherwise you'll catch lungs full of nasty gasoline vapor. That helped one time.

EDIT: I have a stock '70 Camaro Z-28 spec AC fuel pump (new 8 years ago) and Holley Truck Avenger (4150-style) 770CFM carb.
EDIT2: For that highway speed problem -- The pickup/sender in the tank has a "sock" like one more filter to catch the big stuff. Replace the pickup/sender to eliminate that potential problem. Also, rubber fuel hose can get old and fat and swell inside. Check the rubber hose elbow between the tank and the steel fuel line under the back of the cab. It might be swelling and choking off full flow.

[cadillac_al]

Following post #6 should narrow it down.