Interesting symptoms

[TR3driver]

It's there from 1972 and up.

My mistake, sorry!

 

[TheSearcherMan]

You never mentioned the filter that should be just before the fuel pump? Is it there? Also, you can buy some fuel line, hook it to the inlet of the fuel pump, then stick the other end in a gas can, or buy enough to run to the fuel tank, thru the filler. Be careful of a fire.

 

[LastDeadLast]

Yes, fuel filter is just before the pump... and brand new with new fuel line (came with the pump).

I'll have to ponder the "gas in bucket" idea.

At this point, I'm starting to think that the change in ameint termperature might be affecting the gauge. I might get a non-oil filled gauge just to see if that fixes my problem.

-S

 

[Norton47]

A question/thought. What about the check valve in the fuel pump letting go instead of holding a steady pressure?

I think the book tells you to check the pump by installing a pressure gauge and cranking or running the engine on residual fuel in the card and verifying around 2 PSI steady. It is also suppose to hold pressure for a short while once the cranking or running is stopped. If it bleeds off to quick it's a sign of trouble.
Sorry not better details, going from memory after a quick read.
maybe someone else can elaborate?

 

[Brosky]

Norton,

The only problem with the check valve theory is that it's losing pressure while running as well as when sitting.

Time to start with basics and process of elimination. What is the last changed part that was done prior to the problem? If the pump was changed back to the old pump, it has to be the fuel filter. Eliminate it or change it and see what happens, since there is no restriction the the return or pressure build up in the tank.

BTW, did you check those lines at the rear yet to make sure that they're not collapsing?

 

[DrEntropy]

I think isolating the problem by using a separate fuel container is a good first step. If it runs past the 10 minute mark on an external supply with 2 PSI, you've isolated the problem to tank and lines. If pressure diminishes you have pump issues. I'd trust th' gauge to be accurate, BTW.

 

[TheSearcherMan]

I didn't mean "bucket". You could run a 1/4" hose thru the small gas can neck, and keep the fumes down. A bucket will have alot of fumes. And, you may want to do this outside, with a fire extinguisher.

 

[LastDeadLast]

I didn't mean "bucket". You could run a 1/4" hose thru the small gas can neck, and keep the fumes down. A bucket will have alot of fumes. And, you may want to do this outside, with a fire extinguisher.

I know... that was my lame attempt at inserting humor in my reply. But it's sounding more and more like a great idea. I'm gonna pick up the fuel line tomorrow.

-s

 

[Brosky]

Speaking of buckets of gasoline, where in the heck is Dale???

 

[TR6oldtimer]

Didn't he have a simular problem?

 

[Brosky]

Yes, I think that he did, but I don't know if he ever solved it, so that's why I asked about him.

 

[LastDeadLast]

OK, an update.

I took TheSearcherMan's advice and completely bypassed the fuel system and ran a fuel line into the fuel pump. Same exact symptoms... fuel pressure is great for 5 minutes then slowly goes down to nothing... car still seems to run OK though (at least in the garage). I even let about 4 gallons of fuel flow from the tank into my gas can... there is no obstruction.

When all the stuff started happening, I ordered a fuel pump rebuild kit from TRF and it came in the other day. I took my AC fuel pump that I was using when the problem started happening and rebuilt it (again). I did find out that the plunger was made incorrectly compared to the Bentley and the new rebuild kit. The spring retainer cup was on the wrong side. Don't know if this affected the performance, because it ran for a year like that, but it right now and it seems to "suck" better.

I installed the newly rebuilt pump and started it up, still with the lines bypassed. Same thing, great fuel pressure, then over 10 minutes time goes to zero. I'm wondering if my gauge is getting inaccurate as the engine/fuel warms up. I've read were those oil filled units can do that.

Anyway, I slapped it back together and I'll drive it around tomorrow...we'll see. I tested every component that has to do with air/fuel/spark and I can find nothing wrong... but it seems to be doing great now. I hate these types of problems.

 

[fogdot]

Exactly where in the system is the pressure gauge tapped in? It seems that the problem would be between the pump and the point where the pressure is taken.
I had a similar problem in another vehicle with gravity feed fuel. I disconnected the fuel line at the tank,and put a rag over the end of the line. I "reverse flushed" the line with air pressure. When I blew out the line, the rag captured enough trash to restrict the fuel. Nothing major, just 50 years accumulation of small pieces of trash.

 

[LastDeadLast]

Exactly where in the system is the pressure gauge tapped in? It seems that the problem would be between the pump and the point where the pressure is taken.
I had a similar problem in another vehicle with gravity feed fuel. I disconnected the fuel line at the tank,and put a rag over the end of the line. I "reverse flushed" the line with air pressure. When I blew out the line, the rag captured enough trash to restrict the fuel. Nothing major, just 50 years accumulation of small pieces of trash.

I've got the fuel pressure gauge mounted about 6 inches after it clears the engine (on the passengers side of the engine), right before it hits a fuel block that splits the line into two. Everything past the pump is all brand new stuff with no leaking, so I hesitate to blame it.

Is it possible that my fuel block is acting as sort of a "reservoir" thats causing the pressure to drop when it hit it? It's not very large and I've got 1/8" lines in/out.

I think the fact that I bypassed the tank and fuel line pretty much eliminates anything before the pump as the culprit.... at this point, I'm not even sure that there IS a problem.

-s

 

[Tinster]

Yes, I think that he did, but I don't know if he ever solved it, so that's why I asked about him.

<span style="color: #000099">Yes Paul,

I had similar sounding problems a few times.

1. Fine rust got past the filter and filled my carb bowls
2. Two defective aftermarket fuel pumps
3. Bad condenser can in distributor.
4. Potato in exhaust pipe was the culprit the last time.

The car is operational today - over a week without a breakdown.

d</span>

 

[angelfj1]

"Potato in exhaust pipe was the culprit the last time"

what kind of potato was it? Idaho? Russet? Yukon Gold? Peruvian Blue? Superior? Kennebec?

It's important to use the proper potato! :smirk:

 

[Tinster]

"Potato in exhaust pipe was the culprit the last time"

It's important to use the proper potato! :smirk:

<span style="color: #660000">My best guess, based upon the loud, shotgun
like blast, when the potato fired out the Crypt Car's tailpipe
would be an Earp potato from the Tombstone farms in AR.

</span>

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]The car is operational today - over a week without a breakdown.[/QUOTE]

Very good. Now if you could just stop those tropical storms.....