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fuel delivery dilemma


TonyHavana
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I parked my car about 2 months ago now, and have not been able to start is since.

I've gone through the entire fuel system, cleaned the sending unit, new filter, had the pump checked out (it's fine), new fuel hose and b-grade clamps while I was at it. But still nada. Fuel is getting up to the new filter. SO the only thing I can think of is the cam lobe is worn, along with the actuating rod, and is not traveling far enough for the pump to function properly.

I'm ready to go to an electric pump, but it's a ti and trying to stay original.

Here's the question: can I take a bit of thickness off the bakelite mount from the pump to the head, thus allowing the actuating rod to go deeper into the pump?It's this, or a new cam, which might be hard to find for this car, not sure what exactly it is, have the cam lobe welded and reground, or as mentioned before, just go electric? It's not as if it's difficult to return to stock some day.

As always, thanks in advance.

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problem...have you tried submerging the pump's inlet hose in a jar of gas and having someone crank the motor to see if the pump is functioning? Or have you bench tested it, doing the above but manually pushing the pump's actuator pad?

some things to check:

1. the rubber fuel line that runs from the firewall to the fuel pump: If it's cracked, loose or porous (esp those OEM hoses with the braided covers) the pump will suck air, not fuel. Mechanical pumps do best pushing; electric ones, sucking. Try a new section of hose, and/or make sure the clamps are tight. If you have a take-apart metal and glass fuel filter, make sure it has no air leaks.

2. Check the pad on the pump that the pushrod bears against. If it has a groove worn in it, you won't get any pump action. The Italian aftermarket pumps are notorious for this; I had one actually wear through!

3. Both ends of the pump pushrod should be flat, not beveled. It doesn't take much pushrod wear (especially coupled with pad wear above) to make the pump work fine when you bench test it, but not when it's on the car.

FYI there are two different length pushrods--one for the "take apart" pump used on the earlier cars, and another for the crimped together pumps that are on newer cars, and are the ones sold new currently. But since the car was running previously, it's unlikely that the pushrod grew or shrank. Also, the cam lobe looks OK to me; I'd suspect one of the three things above first.

cheers

mike

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Should have mentioned it...when carbs are primed, it fires right up for a few seconds.

All hoses, clamps and filter are new and tight, from firewall on.

Had the pump bench tested at a carb rebuild shop. He said it's fine and proved it to me.

Fuel makes it up to the filter, and into the pump, just not out to the carbs.

There is a small groove on the pump pad but nothing near the amount of wear on the other two old pumps I have.

The rod I am sure should not be bevelled as it is, that's the wear issue.

I disconnected the out-going line from the pump, and put it into a bottle and nothing comes out.

Thanks for you ideas, but need more.

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But if they were gunked up Pat, would they still fire when primed?

And no fuel is coming out the carb side of the pump when engine is turned over.

yes, since the fuel you spray goes directly into the intake port of the motor (assuming you prime them "externaly").

that just proves that the carb are inop.

isnt there a mesh filter at the inlet of the carb ?

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OK But shouldn't the fuel pump push gas out to the carbs? As I mentioned earlier, I put a water bottle on the hose that feeds the carbs, and turned the motor over several times, but no fuel in the bottle. Not sure about the mesh filter, but I guess pulling the float covers off the carbs is the next step.

Thanks.

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OK But shouldn't the fuel pump push gas out to the carbs? As I mentioned earlier, I put a water bottle on the hose that feeds the carbs, and turned the motor over several times, but no fuel in the bottle. Not sure about the mesh filter, but I guess pulling the float covers off the carbs is the next step.

Thanks.

its not clear...

how do you prime them ?

you said fuel is getting into the filter...but nothing out of the pump ? not very logical but i would say either the pump is not working great or it is sucking air (think about a rodent that eated up one of the hoses or there is one that has the rubber not old enough or a slow leak).

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When you add fuel directly to the carb as you describe, you by-pass all the jets, floats, needle valve, etc.

When the car was last stopped, was the fuel fresh? Did you add Stabil? Did you run the car long enough to circulate the Stabil through the system?

What happens when you disconnect the outlet side of the fuel filter - does fuel proceed on it's way to the carb?

When was the last time you cleaned the carb and adjusted the float and idle?

I think your issue is carb related and am betting a carb rebuild is in your near future.

Cheers!

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