Odd problem that dumbfounded me...

[Amphicar BUYER]

While at a river in Il, I started to have trouble getting out of the water in my Amphicar with 4 people on board. The car simply lacked the power to get out

with out dying. I figured it may be the plug wires as that was the

cause for it missing earlier in the day. I thought the cap may have

a crack in it too.

When I got home and went for a swim I noticed sometimes it would

hesitate a bit. Then one day after a short 20 mile drive it

hesitated, chugged and the acted as if it was out of fuel then died.

I thought it may be vapor locking because after a short time it

would start fine, but still acted as if it was starved for fuel when

under load. I had installed a switched electric pump for this event.

I turned it on and off I went home. At first it had little power and

chugged severely, then all of the sudden it cleaned up and the next

10 miles it was perfect. The next day I went for another 20 mile

drive and this time it would not restart once it quit, even with the

electric pump. I got towed home. That was embarrasing!!

The car when cold, starts fine, runs strong and will all idle day

w/o problem (three times @2200RPM for 15 mins too). Drive it for a

mile or two and it sputters, jumps, backfires slightly out the

exhaust and dies. Turn on elec pump and it will idle all day again.

Drive a mile or less and it chugs sputters and dies again.

I rebuilt the original mechanical fuel pump. Same problem.

Rebuilt the fuel tap and cleaned out an already clean fuel tank, same problem

Rebuilt the carb, same problem

Cleaned out all screens and new inline filter, same problem

Blew out the fuel lines, same problem

Replaced the coil, same problem

New distibuter cap, same problem

Got tooooo frustrated, Took it to a local guy, he had it all day

changing out the Pertronixs ign and trying what ever he thought I

may have missed. He brought it back tossed his arms in the air and

said "ok, I give", same problem

What was the problem? I did find it. What I want to see is what the

rest of you think I was. What is your best guess??

I'll let you know in a couple of days what the answer is.

[Guest Randy Berger]

Sounds like a carp swam up your exhaust - the car's , not yours personally.

YFAM, Randy Berger

[hwellens]

I will take a guess. Something in your exhaust system callapsed internally causing back pressure under load, but, would not affect the idle.

[Shop Rat]

I was going to guess that there was a minnow in the bowl of the fuel filter.

[Dave@Moon]

Those Triumph engines are prone to bad/loose exhaust and intake gaskets, which <span style="font-style: italic">can</span> act just like this.. You might try changing them (and checking for cracks that'd expand w/ heat as well). You can do a quick check with a butane lighter to see if it's the intake gasket. While the engine is stumbling hold an open, unlit lighter around the edges of the gasket. If the escaping butane gets sucked in, smoothing the engine's performance, you've found your leak. (Obviously do not do this if there's even the faintest potential of a backfire igniting the lighter! )

Good luck!

[Guest invicta592]

Was the engine flooding?

[Ron Green]

My first guess would be that your fuel vent that exits thru the horn body was clogged or pinched however it could be something in the exhaust going shut once it starts getting hot.

I know that is 2 guesses but it is a tough one since it appears that you have emptied the parts bin tracing it. Note: I only seem to get one season out of a rotor before a ever so slight miss starts to appear.

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Was the engine flooding? </div></div>

Nope, no flooding, no exhaust problems, no vent problems.

See why this one was such a problem. HINT - Took $10 to fix ...

John

[novaman]

I don't really know enough about these car but I'll take a wild guess.

Considering everything that was checked, any chance that there was a problem where the transmission driving the props was hung leaving them engaged while going down the road?

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I don't really know enough about these car but I'll take a wild guess.

Considering everything that was checked, any chance that there was a problem where the transmission driving the props was hung leaving them engaged while going down the road? </div></div>

Good guess, but no prize! Leaving the props engaged only makes some noise and finger pointing.

John B

[Ron Green]

Sure is a mystery. Almost seems like something electrical?

I am willing to give you $20 for all those used parts you now have!

[Jay Wolf]

My guess would be fuel starvation.

Amphicars have a bad habit of vapor locking when boating.

if you look the fuel line runs around the head, and get very hot.

Relocate the fuel line of wrap it with foil. That worked on all mine.

The one I used to show I used the wooden clothespin idea and it worked but I never really drove that one the hard.

I was always surprised how much harder he motor had to work in the water than on land.

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Sure is a mystery. Almost seems like something electrical?

I am willing to give you $20 for all those used parts you now have! </div></div>

For YOU Ron, of course I'd take the $20! I'll post the list of what to expect in the mail after I reveal the answer.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Amphicars have a bad habit of vapor locking when boating.

if you look the fuel line runs around the head, and get very hot.

Relocate the fuel line of wrap it with foil. That worked on all mine.

The one I used to show I used the wooden clothespin idea and it worked but I never really drove that one the hard.

I was always surprised how much harder he motor had to work in the water than on land.

</div></div>

Jay - They actually work less in the water under normal power (not full on). On land - ~30 MPG @60MPH = 2 Gallons/Hr and in the water - about 1 1/2 Hrs/Gallon or about 30% better. They have less air flow over the louvers so they tend to run warm in the water. I added the in-line electric fuel pump to eliminate the vapor locking.

Your on the right track though....

John Bevins

[Bob Kinker]

Is there a rubber hose on the suction side of the mechanical fuel pump? Maybe it was collapsed?

[DizzyDale]

Dear John,I pretty much had the same problems with my 62 Corvette.I ended up changing the ballast resistor,points,condensor and coil,ALL problems solved.diz

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Is there a rubber hose on the suction side of the mechanical fuel pump? Maybe it was collapsed? </div></div>

[color:\\"red\\"] <span style="font-weight: bold">DING DING DING!!</span> We have a winner! Bob you got it. The 8 foot long rubber fuel line from the tank to the pump became too soft and the suction collapsed it once it warmed up a little. I don't know what you won, but what ever it is... it's gotta be good!

I had never came across that problem before, hard and brittle yes, but never too soft to hold any vacuum. The fuel line was from NAPA and only 4 years old. I just used the old to pull thru the new. When I next pull the floor, it will be changed to stainless.

John Bevins

[novaman]

What rubber hose on the suction side?? If you had a Chevy II you wouldn't have had that problem ...although they don't travel in deep water very well or float very long.

Now I have to ask. Was this hose/line suppose to be all rubber or was that someone's engineering job?

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What rubber hose on the suction side?? If you had a Chevy II you wouldn't have had that problem ...although they don't travel in deep water very well or float very long. </div></div>

Yea, I think it would flood pretty easy before the end of the dock! Don't forget to hold the gas pedal down while cranking it!

The fuel tank is in the trunk up front, the engine and fuel pump is in the rear. The hose goes 8' from the tank to the pump.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Now I have to ask. Was this hose/line suppose to be all rubber or was that someone's engineering job? </div></div>

Originally they were cloth coated rubber, I replaced it during restoration with high presure rubber from NAPA. Maybe a bad batch?

John

[Guest JT]

If you're in an area that uses reformulated gas (MTBE or ethanol) it will shorten the hose life. How many years old is the hose?

Good job on the diagnosis Bob

[Amphicar BUYER]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">If you're in an area that uses reformulated gas (MTBE or ethanol) it will shorten the hose life. How many years old is the hose? Good job on the diagnosis Bob </div></div>

The hose was only about 4 years old.

John

[Bob Kinker]

How about a ride in an AMPHICAR? Next time you come to VA.

[Guest De Soto Frank]

I ran into similar problems with my '60 Windsor during its first month back on the road, although my cause was excessive rust floating around the fuel tank.

It would pass enough fuel to idle all day, or even to drive a few miles at modest speed. But if I went hard on the gas or tried to drive on the highway, within a mile or so, fuel demand would outpace supply, and she'd be coughing her way over to the shoulder...

Eight feet is an awfully long legnth of rubber suction line to be exposed to atmospheric pressure of 14 lbs/sq in...even if it worked when new, it sounds like an invitation to trouble in my mind...

[Guest JT]

Frank, I thought eight feet of fuel line would be a problem too but didn't really know if it made a difference if we were talking about a 1 ft hose or an 8 ft hose as far as the effect of vacuum and atmospheric pressure?? Is there a formula for this?

[Ron Green]

John,

Thanks for posting this problem as it was rather fun following all the great thoughts from everyone. I see the Amphicar website still didn't get it yet but they are narrowing it down. Good job Bob.

I bought my fuel line from Hugh a few years back and it was very expensive, approximately $6 a foot I think and made in Germany. A friend who restores vehicles for a living checked it out and commented that it was of extremely high quality. It has a braided exterior sheath.

I wonder if the use of new fuels may have prematurely softened the line along with the heat? I use the NAPA commercial hose from the heater core to the engine, as you know they are very long. You have to ask for the good hose as they are typically in the back as most won't paid the extra dollars. I know NAPA here is starting to carry junk parts as the counterman stated "they have to compete with the other supply houses".

Now about all them spare parts you have laying around.

[Amphicar BUYER]

Ron - Mark R. finally got it in the Amphi forums. It was probably the MTBE in the fuel that softened the line. Hugh's $6/ft lines are nice and a quality correct part (for once). I will be replacing it with a hard line because I drive my Amphi too much not to.

So you still want the 8' soft fuel line (slightly soiled), fuel pump diaphram w/hole, fuel pump valves, various gasket pieces, crcked after-market dist cap and a used fuel filter? I got your address, it'll be on the way!

John Bevins

[Ron Green]

Keep them (parts) and figure how to make a still out of it. Better yet make sure you bring the Amphicar beer to Celina, I'll kick in for a keg.