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Weak spark I think?........

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Jim - please let us know what happens when you try starting after spraying gasoline into the carbs.

If the car's been sitting for quite a while, there could be:

bad gas
no gas
crud in lines and jets
etc.

If the engine runs with a couple spritzes of gasoline, then you've pretty much eliminated the electrical problem possibility, and narrowed yourself into fuel delivery problems.

Tom
 
In answer to "<span style="color: #FF0000"><span style="font-style: italic">What are the odds that both (carbs) would stop working at the same time</span></span>? ", both carbs don't have to be stopped or blocked for the car to be nearly impossible to start. Off and on, I have had problems with our GT6 sitting for long periods of time and refusing to start. It has always been 1 of the 2 carbs that is somehow blocked (either a stuck float valve or gummed needle/jet). I could sometimes get the car to start on one carb but I could not keep it running or generate enough power to move the car.

BTW, the spark in the videos looked good to me. I would only question the spark if it appeared very orange.
 
ETHANOL. :madder: :wall:
 
First fuel system discovery.

Found that the forward carb has a badly deteriorated rubber (nitrile?) gasket as below. It was definitely leaking some fuel but very slowly and could only be felt if you put your hand under the lowest part of the fuel bowl. Clue was when I inspected the fuel bowl levels, this morning, the forward bowl was obviously lower than the rear one. I tested out the float valve and that is working fine so I looked a little closer.

Question. Would the small leak, maybe also air being sucked in through that leak, been enough to keep my engine from running? I have my doubts on that. I will of course be replacing this gasket. I am also going to be looking for one of those aerosal glass bottle things they have at hardware stores now for spraying paint so that I can try spraying regular gas in my carbs to see if that makes them run. My thoughts are that even if this leak did allow the fuel to leak out of the bowl so that it was half as full after a night of leaking, I don't think that would account for my engine not running on my own fuel. Again, it is in some ways a redundant fuel system in that there are two carbs. Even if that one was not providing any gas I would think that the engine would at least show some sign of trying to run on the remaining two cylinders.

Photos of failed gasket a following.

P1220131.JPG


P1220132.JPG
 
Seems to me that in order to not run it would have to be a major leak to suck enough air in. As long as the other carb isn't leaking in the same way it should be trying to at least keep 2 cylinders running especially with the choke out.
 
Jim Lee said:
Question. Would the small leak, maybe also air being sucked in through that leak, been enough to keep my engine from running?
Click to expand...
Nope. It can't even suck air, as the pressure at that point is always slightly positive.

It would make the engine somewhat hard to start, but only for as long as it takes the pump to fill the bowl again. And with the choke pulled (hmm, you are using the choke, right?), the engine will run (poorly) on the other carb until the leaky one fills up.
 
Jim Lee said:
Found that the forward carb has a badly deteriorated rubber (nitrile?) gasket as below. It was definitely leaking some fuel but very slowly and could only be felt if you put your hand under the lowest part of the fuel bowl.
Click to expand...

very common problem, but it wouldn't affect performance. Since the leak was slow, the pump would definitely keep the bowls filled to the proper levels.

Jim Lee said:
Would the small leak, maybe also air being sucked in through that leak, been enough to keep my engine from running?
Click to expand...

definitely not. The only way that could possibly happen is if there was no fuel around the gasket - and the lack of fuel would be a bigger fault than a vacuum leak.



Back to basics, apologies if this has already been asked.....
1) is the choke working properly? (jets moving up/down)
2) do the pistons move freely?
 
I used a dropper to simply drop a small amount of raw gas at the opening where the air cleaner normally is. It ran once, which really got me excited about at least determining that it was not getting fuel, but then did not run the next 3 times I did that. I then took gas from the car and put it into a spray bottle. That did not run. I am now going to the gas station to get a brand new gallon of premium gas. I have removed the float bowls and cleaned them. As you can see in the 'before' shots below they were not very dirty. The passage from the bowl to the bottom of the carb was, and is, completely clear.

My plan is to pour the gas into the empty bowls and hope that the missing 2 or so pounds of pressure provided by the pump is not going to make a difference. If that does not run then plan B is to hook up the one gallon tank to the fuel line before the pump. If that doesn't work then I am right back where I started from ruminating on ignition issues.

Pics:

Spraying through main jet. Goes right out of the bottom of the carb with the bowl disconnected as expected.
P1220135.JPG


Clean needle:
P1220137.JPG


Before picture of bowl:
P1220138.JPG


Plan A setup. Put brand spankin' new fuel in clean bowls that I know have a direct passageway to the carbs.
P1220140.JPG


Stay tuned for further developments. Sorry about the confusing captions. You guys will figure it out though I am sure.

Thanks,
Jim Lee
 
Jim - those bowls sure look dry to me. Was there any fuel in them when you opened them up?

If the bowls are dry, then no fuel is getting to the carbs. That would indicate a problem between the lines at the carbs and the fuel pump and/or filter.

Tom
 
Disconnecting the pump will not be a problem as long as you manually fill the float bowls. During running, the pump is not pushing fuel into the jet or throat of the carb, only into the float bowl. There isn't 2 PSI behind the fuel as it enters the jet.

As long as the carb is apart, are the pistons free to rise and fall in the vacuum chamber? Are the jets centered? Are the crossdrills between the float bowl and the carb bodies open? Are the carbs secure the the manifold and the manifold secure to the head?
 
What do the plugs look like? It is possible to have more than one problem going on. You might have flooded it in the beginning and fouled the plugs and perhaps the high octane could have still popped, but the gas will not. It does sound like a fuel problem because the spark picture looks strong enough to start it. Do you have a good delivery of fuel? Or perhaps the vehicle was just starting to run out of gas in the tank and had no fuel pressure..
Steve
 
Yes. Filled with plenty of bad fuel that refused to ignite.

Thanks to the patient, kind and generous efforts of the Forum my Black Beauty is back on the road delighting kids who have never seen such a thing.
It was, as most suggested in one way or another a VERY simple thing. The gas was bad. When I poured the brand spanking new fuel into the empty bowls, lighting struck and my Blackened Beauty woke up. I guess that in my old age I am forgetting how long the gas has been in there. I also had given myself a false sense of security because I would periodically dump that stuff in the tank that is supposed to make it last forever. I am here to tell you it don't last forever.

The rock and the hard place that I see in keeping fuel fresh, or at least ignitable, is that I always try to keep my tank full because someone once told me that if it is not full your tank will rust away. But with it full that means you have that much more gas to grow old if you are not driving often enough. That was my mistake. Not driving often enough. I thought I was compensating for the full gas tank by putting the 'dry gas' in to preserve it. I got cocky on the freshness of my fuel. Let this be a lesson to everyone who does not drive their TR as often as they should.

I am not feeling bad about the experience because it gave me a chance to get reacquainted with my intake system and make sure everything is as it should be. For example I now need to replace that gasket on the bottom of my carb though the only 'damage' it has been doing is to drain some fuel out of that one bowl overnight...or between outings. Of course I now have a series of questions on other parts of the car but I will ask them in subsequent postings instead of defiling this post.

Finally, I bet you thought I would never stop with the chatter, this is hands down the most responsive forum I have ever seen. It is amazing. I am on a few other auto specific related forums and they are very helpful but nothing compared to this place. Keep up the good works.

Thanks very much,
Jim Lee
 
Jim - I'd bet a few of us are wondering .... How long had that gas been in the tank?

In your very first post, you said "the gas is not old".

Also, was it 100% gasoline? or E85 gas/ethanol? or ...?

The more details you can share, the more we can learn.

Thanks.
Tom
 
I'm glad you got it sorted.

The gas in our GT6 is embarrassingly old while that in the Mini and Spitfire are constantly replaced/refreshed.
 
If you leave the tank full for a long time and the ethanol soaks water into the fuel, then the water will rust the inside of the tank. So the latest news is to leave the tank empty or nearly empty. In 1990, when I finished my restoration, I had the inside of the tank slushed or coated with whatever the fuel tank shop was using back then. With ethanol in the fuel now, I can't say that the coating inside my tank might be peeling off or dissolving away, but I have put a fuel fulter in the fuel line just in front of the rear axle in my 1958 TR3A.
 
There is no more single more enjoyable thing to experience for me than getting some thing to go that wasn't. Awesome now go drive it before they throw salt if they haven't already. We are presently getting a reprieve and ready for winter projects but am still enjoying some driving. Cudos
 
Jim Lee said:
because I would periodically dump that stuff in the tank that is supposed to make it last forever.
Click to expand...
Just curious, Jim, which stuff did you use? They are not all created equal, and I've heard that some of the older formulations are not compatible with E10 (which is probably what you are getting whether you know it or not).

<div class="ubbcode-block"><div class="ubbcode-header">Quote:] by putting the 'dry gas' in to preserve it.[/QUOTE] "Dry Gas" is not a preservative. It actually is alcohol (mostly) itself, intended to keep any liquid water from freezing in the winter time (and blocking all fuel flow). Adding it to gasoline that already contains alcohol is a waste of time and money. There are some additives that are supposed to help keep even E10 from getting stale (eg Sta-Bil) but I don't know how well they work.

One solution that I may pursue myself is to stop letting fresh air into the gas tank. I already have my overflow tube blocked off, because it can allow fuel to spill onto the street in a hard left turn (like the turn I make every morning out of my subdivision onto the main road). Seems to me that it would not be too hard to block off the vent in the cap instead, and use a check valve & DC solenoid to block off the tank vent when the car isn't running. Maybe even route it to a carbon canister with a purge line to the intake manifold.
 
"Jim - I'd bet a few of us are wondering .... How long had that gas been in the tank?
"
I wish I could tell you but since I cannot I would say a couple of months minimum.

"In your very first post, you said "the gas is not old"."
I have redefined the word 'old' as far as the gas in my TR3 goes. I plan to drive it more regularly. I have a hard top and a heater, plus I live in North Carolina, so I have no excuse not to."

Also, was it 100% gasoline? or E85 gas/ethanol? or ...?
100% gas as far as I know though I believe that they stick ethanol in our gas at some point in the winter.

"The more details you can share, the more we can learn."

The main lesson I learned was not to get so cocky about how new your gas is.
Also I think it was 'Sta-bil' and not dry gas that I put into the tank. I could not think of the name of that stuff. I need to hunt down that bottle and double check. If it was I am selling my Sta-bil stock tonight.

"So the latest news is to leave the tank empty or nearly empty"
Thats good news.

"....getting some thing to go that wasn't..."
Affirmative to the highest order. The weather here in Raleigh has been so nice during the day that even with a million other things to do I could not stand not having my Black Beauty aka My Friend Flicka on the road doing its thing.
I can hear it saying "Free at last, free at last, oh lawd..."
 
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