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SU H6 Carbs?

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PlaidMan

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I have a 1958 TR3A that had gas from an old gas can poured into the gas tank. I found what looked like 1 inch pieces of Horsehair stuck in the Grose valves , it evidently passed thru the fuel pump and a filter before the carbs. The sediment bowl of the fuel pump had multiple pieces of this material in it. Obviously I cleaned the carbs and used a new gasket kit as the carbs are only one year old. I also changed the fuel pump and put two filters on the fuel line, one before the fuel pump and one before the carbs. Question? The engine ran good for about five minutes and now it will barely idle and if you try to raise the idle speed it will just die. Kind of sounds as though it is choking. Do you think some more trash in the fuel line could be blocking the fuel flow thus creating some kind of vacuum? What else would cause it to barely idle and if you turn the idle speed screw to raise the idle it will die. The float bowls do have gas in them at this time. All help appreciated, Thanks Charlie
 
Charlie, I suspect what you need to do is start again with the carbs, clean them out...and then work your way backwards through the fuel system right back to the tank, cleaning EVERY bit along the way. Whatever that "horsehair" material is, it's likely scattered throughout the system.... /bcforum/images/%%GRAEMLIN_URL%%/frown.gif
 
I did drain the tank but I didn't disconnect the fuel line at the tank, so tomorrow looks like I might have to remove the gas tank to clean it. I had cleaned everything from the fuel pump to the carbs, guess I'll be doing that again, not to mention two new filters.
 
Hi Charlie. If you haven't removed the fuel lines yet, this could be the next good area to look at. Specifically the small pieces of rubber fuel line that interconnect the steel lines here and there, usually at an elbow area. Rubber fuel line, especially if it is old or ancient, will swell and often completely block the flow of fuel. Had that happen to my last TR6 in the 80's (the one before this one). (Left me dead in the water, had to sit a gas can on the open engine compartment to get home, with a rerouted, temporary rubber fuel line. Danger not a factor, simple lunacy.)

Check out your fuel lines.
 
Charlie, you live just up the road from me but I don't think we have met yet. We had a run this last Saturday for 2 hours through your neck of the woods, ended up over in Henderson and ate at Pat's. Got caught in that swamper coming home to Franklin, had my rear window un-zipped. Took two days of fan blowing through the interior to dry it out. Such fun.
 
Bill, might try that gas can to verify if a blockage is present in the gas tank before I remove it. I'm helping some friends who own a local restoration shop as they only know American made vehicles and their specialty is paint and body work. I would love to go on a run but my TR3A's frame is waiting on paint at this time and it will be a while before it hits the road again. Do you belong to a club in your area? I don't know of any clubs around Lafayette but I always have an ear open .Thanks for the help, Charlie.
 
I tried the gas can method but that didn't change things. I'm thinking Ignition problems, I can't go beyond idle speed at all. Which wire should connect to the points spring arm and which wire attaches to the post of the points? These two wires should be separated by the plastic insulator, right?
 
Nope. Both wires go together, under the plastic insulator and against the spring of the points. Nothing connects to the post at all, it's only function is mechanical.

But since the engine runs at all, your problem isn't likely to be something wired wrong, IMO. Bad condensor, point gap wrong, lots of things like that could be, but the wiring is pretty much "all or nothing".
 
Checked the carbs today, seemed OK. Put new points, cond., and rotor for the second time. Started ok but after a couple of minutes it started to miss when revving the engine and after about 10 minutes I could not raise it above idle without it dying. During this time I tried to set the mixture using the colourtune system but after screwing in the mixture nuts all the way in it was still showing a yellow flame. These carbs where knew about a year ago and worked fine then. Could this be a coil problem? Mine gets hot to the touch. Randall, I had one wire under the insulator and one on top of the insulator under the nut. I tried putting both wires together once but my test light did not light up so I thought it was wrong.That would explain why the holes in the connectors are the same size as the insulator.
 
Well, it seems clear something is going downhill quickly when it gets hot. Could be the coil, I guess.

Normally, a yellow flame means the mixture is too rich; but I suspect it could mean other things as well. Oil burning for one. But I have no idea if it could also be ignition problems.

Have you checked the valve lash recently ?
 
Actually, I did check it today and reset it. The engine was rebuilt about a year ago , no oil burning. I'll try new needles and tubes in the carburetors since I have them already. Maybe the rich mixture is good when it's cold but get's worse for the engine as it warms up. Turning the mixture nuts made no difference at all.
 
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