My GTC died on the freeway...argghhhh!

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Steve Meltzer
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My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

I was driving the GTC on the freeway going about 80 miles an hour when the car began to slow and eventually die in the safety lane. As always, the electric fuel pump was on and had been running when I took the car out that morning. (ambient temperature was about 70°; not hot)

After seeing that the alternator belt was okay, I began to suspect I was out of gas, though the gauge which had previously failed and been repaired, showed the fuel at three quarters of a tank.

The car would crank perfectly but not fire up. There was so much noise from the passing traffic that I could not tell if the fuel pump was functioning or not but I think it was not. The roadside service came and put a few gallons of gasoline in the car thinking that the gauge was inaccurate, but no no such luck. The car would not start, though it cranked normally suggesting that the problem was not electrical. Again I could not tell if the e-fuel pump was running or not,; it was in the on position as it always is. Peering down into the carburetors showed no gas from the accelerator pumps, whatsoever. I called a flatbed and the car was towed to my house where it started immediately upon landing. (of course!)

Once home, it became quickly evident that the fuel pump was running correctly and all three carburetors had excellent accelerator pump shots. That was with the e-pump on, and the car not running. I drove the car for about 15 to 20 minutes in my neighborhood with the e-pump running and had no trouble at all.

This morning, I started the car and drove the car for about 15 minutes with only the mechanical pump running and no electric pump. Car started fine and ran great. I had no trouble with it. Also, my gas gauge said three quarters of a tank, and I filled it to the top but it only took four more gallons. Therefore, I would conclude that the gauge is fine and the problem is almost certainly a fuel related issue, unless there is a gremlin affecting the electric fuel pump.

Where do I go from here? I think it's safe to say that with the fuel pump running I have good fuel flow. Not sure why the mechanical pump did not provide enough fuel to get it started when I was stranded on the freeway, even if the e-pump failed (?temporarily?).

Sorry this is so long-winded. Steve
steve meltzer,
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Steve Meltzer
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Re: My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

I'm pretty much used to talking to myself, so here goes again. Looking at the e-fuel pump there are no loose connections and applying 12 volts to the pump itself makes it work great, consistently. However, with the e-pump switch in the "on" position, the pump does not "see" 12 volts nor does it work today. So, I conclude that the problem is in the switch not the pump. If you "fool around" with the console switch, you will find the pump works intermittently.

This still doesn't explain why the mechanical pump appears to have failed me when the e-pump died. ?? red herring and thus a second problen ??
thanx s
steve meltzer,
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Fasthound330
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Re: My GTC died on the freeway...argghhhh!

Post by Fasthound330 »

Well, that sure sucks!

Is there a relay between the switch and the pump? If so, look there. But you know that, of course.

I wish I could help, but I’m too much of a novice with these lovely machines. Ike offer to go check voltages, etc. but mines in the shop, as you know.

Good luck sorting this one out.

Kevin
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Re: My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

Kevin, thanx for the great pun, but apparently it doesn't suck enough! One of my friends brought up the possibility of the relay, but as I look at the schematic, which I admittedly am terrible at reading, I don't see a relay between the switch and the fuel pump. Nor do I recalling seeing one in the past. It looks like a fairly straightforward "on /off "switch, but the thought of taking out the console and getting to it is daunting.

As you know, at this moment, Harbaugh and the boys have not disappointed. Certainly gave us our comeuppance last weekend.

Thanks for your note and thoughts Steve
steve meltzer,
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DWR46
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Re: My GTC died on the freeway...argghhhh!

Post by DWR46 »

Steve; There are no relays in GTC electric pump wiring from the factory. you either had a switch failure or lost power to the switch itself. Check the fuse and make sure it is not corroded.
enio45
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Re: My GTC died on the freeway...argghhhh!

Post by enio45 »

Also - my experience with the Lucas console switches - especially if it is original, they tend to gum up inside and work intermittently - checking with a volt meter u can see sometime when you flip the switch, you get 12 volts, other times 8 volts, other times 10 volts.....this is due to the grease inside causing issues - simple fix is order a new one from GT car parts and that eliminates the switch continuity issue.

Our recent GTC restoration we had similar issues with all the switches and resorted to replacing them all to eliminate low voltage issues. As well, yes make sure your fuse connection is good as well - tighten those screws on the fuse board and clean and tighten the fuse holder ends. I have also found not all fuses are created equal - variations in length by 1/8 or less.

good luck
Ed Montini
330 GT 2+2 Series II - 8289
58 Ellena - 0855GT - orig drivetrain
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Re: My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

First of all, thank y’all for giving me ideas and trying to help me w/the fuel system on my GTC. I did not think there was a relay, but I admit I’d forgotten about the fuse. On inspection of the fuse, there was no evidence of any corrosion at all, but one of the fuse ends looked completely mangled, so I replaced it. However, it did not make any difference with the intermittent failure of the switch. This is consistent with the idea that the fuse, tho’ ugly, was probably still passing current as it should've been.

The decorative holding (?bezel?) nut on the fuel pump switch in the console suggests that it might be removable without removing the console. If so, one might be able to pull the switch proud to the console face, and then try to clean it up with some deoxidizer spray.

While fooling with the switch, I felt a little “give” in its trajectory; almost as if one piece of metal had dislodged some junk from another. Since then, the switch has operated 10 consecutive times with no trouble whatsoever. Perhaps just messing with the toggle cleaned it up enough to work. However, I would still like to get it cleaned up a bit better.

However, I'm still bothered by the fact that the mechanical fuel pump did not appear to function properly and save my sorry tuchus.
This morning, with the e-pump off, the car started and ran on the mechanical pump. I could also demonstrate good accelerator pump shots. These findings occurred with the engine running on the mechanical pump, and the e-pump off. Is this sufficient testing, such that I can be confident in the mechanical pump or, should I take the fuel line off the carburetor and see if it gives engine-driven fuel spurts?

How about this for a unifying theory? Though the ambient temperature was only about 75°, the temperature in the engine bay and around the fuel lines was obviously much greater than that. Perhaps, when the e-pump failed because of the bad switch, the car vapor locked and the mechanical pump failed at that point, as one would predict.

Thus, the mechanical pump would appear to be fine when testing its performance with an hood open, cool morning ambient temperatures in the garage, and the engine essentially cold.

Thanks again. I appreciate your help. Steve
steve meltzer,
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peterp
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Re: My GTC died on the freeway...argghhhh!

Post by peterp »

Steve Meltzer wrote: Mon Dec 06, 2021 1:11 amHowever, I'm still bothered by the fact that the mechanical fuel pump did not appear to function properly and save my sorry tuchus. This morning, with the e-pump off, the car started and ran on the mechanical pump. I could also demonstrate good accelerator pump shots. These findings occurred with the engine running on the mechanical pump, and the e-pump off. Is this sufficient testing, such that I can be confident in the mechanical pump or, should I take the fuel line off the carburetor and see if it gives engine-driven fuel spurts?

How about this for a unifying theory? Though the ambient temperature was only about 75°, the temperature in the engine bay and around the fuel lines was obviously much greater than that. Perhaps, when the e-pump failed because of the bad switch, the car vapor locked and the mechanical pump failed at that point, as one would predict.

Thus, the mechanical pump would appear to be fine when testing its performance with an hood open, cool morning ambient temperatures in the garage, and the engine essentially cold.
I think these 2 different behaviors might be entirely normal (for a vintage Ferrari that is) because those are essentially two different scenarios. The mechanical fuel pumps alone can sometimes be insufficient when there is a lot of heat in the engine bay, which the electric fuel pump can normally be turned on to fix. When your car stopped running on the highway, without the electric pump running, the fuel lines were probably far more vacated because the engine had already sucked as much fuel as it could get from the fuel lines until it died. Also, the vapor lock condition that prevented the mechanical pumps from being sufficient would probably still be happening the issue until the engine cooled down a lot (especially without the electric pump being available).

When you start it in the morning on mechanical only, the engine is dead cold (no vapor lock issues for the mechanical pump) and the fuel line should be pretty full because you had a full fuel supply in the lines last time you shut the engine off (unlike the highway scenario, where all the fuel had been sucked from the lines to the point that the engine stopped running).

How long did you wait on the road to try to restart it? It's possible it might have eventually started on mechanical only if you let the engine cool down a lot.
Peter P
1966 330 2+2 series 2 #8169
enio45
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Re: My GTC died on the freeway...argghhhh!

Post by enio45 »

How about this for a unifying theory?

"" Vintage Ferrari !!!!!!!! The joys of owning one :-) ""

FYI unless you take apart the rivots on the toggle switch, there is no cleaning them with cleaner - makes it worse.....been there, done that!

Related to the electric fuel pump, as you know, you may here it running but not building pressure ....

Sounds like this may be a trail and error until you get a hard failure...
Ed Montini
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Re: My GTC died on the freeway...argghhhh!

Post by afwrench »

Seems like I remember a post about a crack occurring in the fuel pickup in the tank. The tank had plenty of fuel but once the level was below the crack you get no or little fuel. Might be worth a look considering it seems to be a delivery issue. Mike
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Re: My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

First, let me address the least complex question; accessing the toggle switches from the front of the console. As Ed said, you can't do it. I lucked out when I was able to retrieve the decorative bezel I inadvertently dropped into the shifter chasm. Using a Harbor Freight hook, I fished it out. Better to be lucky than good!

With both distributors disconnected, the e-fuel pump off and cranking, I looked for the volume of gasoline spurting from the fuel hose right before it attaches, or where it attaches, to the carburetor fuel rail, and just after the regulator and filter. I was confused and disappointed that there was no volume of fuel flowing at all!

Not being sure that I did a valid test, I decided to try to see if it would run once the bowls were filled and ONLY the mechanical pump on. I guess the system needed to be primed, because it started easily and idled perfectly for about 10 minutes, after they were. Revving the engine increased the RPMs, as it should have, so I suspect the accelerator pump circuits are fine and being properly fed.
NB: the ambient temperature was probably 50°, the engine cold,, and I was sipping my morning coffee safely tucked in my garage.

Peter P, I did not wait any significant time for the system to cool off and let the vapor lock clear. I guess the anxiety of being on the side of a busy five lane freeway prompted me to try and get it running ASAP. (In addition, I'm not known to be the most patient person in the world!) However, I believe that you are correct in your thinking. The mechanical pump is almost certainly fine and if my luck holds out, the switch on the electric pump will continue to function normally.

Thank y’all for your help.
Steve
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Re: My GTC died on the freeway...argghhhh!

Post by Jumprun »

Hi Steve, it appears your problem is not the switch, but if you need a new switch, for this issue or future, I have a nice (maybe NOS?) spare for a Daytona, It is the same switch, but of course it has the Daytona paddle, easily replaced with the micky mouse ear type. Those switches are easily found on Eprey, Lucas brand, functional, but not the same quality as the originals.
Tom in SoCal 11157
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Re: My GTC died on the freeway...argghhhh!

Post by Steve Meltzer »

Hi Tom, I do believe the switch WAS the problem tho' no longer so. I would be interested in purchasing the switch, why don't you send an email to my private email? Thanks Steve <gtc8995@gmail.com>
steve meltzer,
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Re: My GTC died on the freeway...argghhhh!

Post by mechaniker »

I once rebuild a perfectly working mechanical fuelpump because the yellow fuel line was blocked....


Some long time ago, there was an amarican reproduction available, that caused problems, at least here with european fuel. Original style fuel line has a cotton lining inside, the reproduction clear plastic film. The plastic film gets loose and blocks the fuel supply.


After changing the yellow fuel line, the car drove perfectly again. We had this issue often..
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Re: My GTC died on the freeway...argghhhh!

Post by tyang »

Seems like I remember a post about a crack occurring in the fuel pickup in the tank. The tank had plenty of fuel but once the level was below the crack you get no or little fuel. Might be worth a look considering it seems to be a delivery issue. Mike
On Steve's GTC the pickup is at the lowest point between the two tanks, so it wouldn't be sucking fuel from a pick up, but it crossed my mind as I first started reading this thread.

It sounds like Steve has the electric fuel pump sorted by finding an intermittent switch. I don't think there is a way to pull the switch without accessing the back of the panel. I seem to recall GTCs have a removable side panel that might allow you access to the switches.

As far as the mechanical fuel pump is concerned, it obviously moves more fuel at higher RPM, and must be operating at peak efficiency to work properly. Any play in the parts, leaks in the check valves, or extra backlash between the pushrod and the lever will decrease its chances of working all the time. I suspect the sequence of events was this: Electric fuel pump stopped working due to faulty switch, the inefficient mechanical pump plus other factors like fuel vapor caused the fuel bowls to run dry and stall the car. When restarting, the mechanical pump was not efficient enough to provide enough fuel to fill the bowls at cranking speed. Riding back on the truck, the switch on the dash flipped over and made contact (these switches have a fully "over center" feel when flipped), so when you went to start the car again, the electric fuel pump was working again to prime the carbs.

That's my story and I'm sticking to it!

Tom
'63 330 America #5053
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