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General TR TR4A Engine Won't Start

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KVH

KVH

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I took my car for a great ride. Drove perfectly.

Thirty minutes later the car wouldn't start. I cranked it almost to a worn down battery. It seemed to me that upon disconnecting the fuel lead to the carbs, the flow was awfully weak.

Pumping the primer manually showed only weak spurts. Nothing I could do helped.

The sensation was like a dry crank, either no fuel or no spark. I fiddled with the coil wires, readjusted the points, and nothing improved.

But then, suddenly, it started up. Now that it's home, it won't start again. Same thing. Dry cranks.

What do I check first? That pump is only a year old, and if it's bad, that will be 3 bad ones in five years.

The coil I have no idea about. Do I pull a plug wire and hold a screwdriver 1/4 inch away looking for a spark? What should I do next?

Thanks all.
 
Normally it spark or fuel problem not both. In my case I would remove one spark plug and let it on the block to have a mass and I would start the motor and look for the regular sparks, if it's ok I would lift the 2 lids of the SU and check the level of the fuel. "Suddenly it's started" seems more an electrical problem, would check all the electrical connection round distributor etc... IMO
 
If you have ZS carbs, because the fuel pickup for the jet is so very deep in the float chamber, it doesn't require much fuel to get the engine started. If the pump is putting out any fuel at all, it should supply enough fuel to start the engine and keep it idling....that is if the fuel is actually entering the carbs.
 
In my opinion, sudden 'failure to launch' followed by sudden 'A-OK' suggest an ignition problem rather than a fuel issue.

I'd start by checking for spark at a plug, if no then checking from the coil to the distributor.

Have you looked at your points gap lately? They will run with an incredibly small gap but they will do nada with no gap at all.
 
Thx guys. I'm out there now. I think it's ignition too. Problem and fix both too sudden. The car was totally cooled and I've never had a vapor lock. I do worry about a plug at the tank. I'll check that, too.
 
When the car won't start, give it a shot of starting fluid (ether, etc.). If it starts right up, your problem is fuel. If it doesn't, then the ignition system is the source of your worries. Once the malfunctioning system is identified, you'll be better able to chase the specific problem.
 
Guys, I checked everything, then noticed that my points looked very dirty and that cam lobe "nub" was totally worn down. My gap seemed a bit small, too. I put in new points and it started right up. Can I just put any kind of grease on that lobe? Was that likely my problem?

Here's another question. If my fuel bowl is full of fuel, is that a good sign that nothing is wrong with my fuel pump? I'm only asking because that "squirt" when I use the manual priming lever does seem a bit unenthusiastic.
 
That hand pump is only effective at the very top of the pull on most. Try it up there.

Wayne
 
A single pump of the priming lever doesn't produce much fuel in volumn.
If your ZS carb float chamber were completely empty...it would take about 15 pumps of the lever to manually fill it to the needle valve's cutoff level....not that the float chamber need to be full in order to start the engine.
 
Even in the best of times the pump output is unimpressive - in fact 'pump' is probably overstating it. Fuel spurter might be a better label.

I use a dab of assembly lube on the distributor cam. They used to include a small capsule of lube with the new points, but no more. You should use a little something.
 
On the dizzy cam I use moly-grease like you would use on CV joints. I like the idea of the assembly lube.
 
I never mind admitting setbacks, or premature jubilation.

Despite the issue with my points set reported earlier, that wasn't my problem.

I'm still having hard starts and was almost stuck again tonight. Cranked the engine almost to a dead battery. First it ran great, then wouldn't start back up at the gas station. Thirty minutes later it suddenly started.

It really sounded like no fuel. I removed a plug wire to see if I was getting spark, and with the plug removed, my car almost started. As if the cooling off time made a difference.

I can't imagine an air-lock, because I've never seen that happen in one of my TRs.

I also can't see this being the floats. Maybe a dirty fuel filter, though it's only a year old. Back to this: a bad fuel pump? Blockage inside the tank? But my fuel bowl on the pump if full.

Condenser? Coil?

I guess I'll just have to check everything, including the wires to and from the coil and distributor. I'm stumped. Oh, well.
 
You don't need to go to a dead battery, immediately if the car don't start remove a spark plug, let it laid on the side to have a mass and look if you have continue, regular, good sparks. ( I assume the firing order is respected... 1342, don't laugh it happened on a post ). If it's ok, inject "start pilot" ( ether ), if the motor start you have a fuel problem. IMO
 
Roys said:
original Stromberg floats get eaten up by ethanol - Joe Curto has the good ones
Click to expand...

Sorry, I meant to clarify. If have HS6 SUs on my 4A. I'm going to use a test light and make certain I don't have a bad wire anywhere--coil, distributor, etc.

Then, I'm going to dismantle the fuel "in" line, and see if I have regular flow, then I'll dismantle the floats and see if I have a blockage there.

As for the coil, not sure how to test it, but I'll try something there, too. this has to be something simple. It just sort of started.

Thanks for all the input.
 
Take the coil wire from the top of the distributor and stick it next to the block. A blue spark of 1/2 inch is great, a little yellow will do. Simply enough.

Wayne
 
Others have suggested how to check for good sparks. I'll comment on fuel.

Since you have HS6 carbs, do the following. When the car acts up while driving, switch the ignition off and put the gearshift in neutral as quickly as you can. Pull to the side of the road and stop. Remove the float bowl lids and examine how much fuel is inside. Each bowl should be about 1/2 to 2/3 full of fuel. If they have less fuel or no fuel you have a fuel delivery problem. It could be any number of things... plugged pickup in the tank, perforated pump diaphragm, plugged filter, plugged float valves....

As TR-Beg suggested, another test is to tip a thimble of fuel into each carb throat and try to start the engine. If it runs very briefly and stops you know you have restricted or blocked fuel flow.
 
dklawson said:
Others have suggested how to check for good sparks. I'll comment on fuel.

Since you have HS6 carbs, do the following. When the car acts up while driving, switch the ignition off and put the gearshift in neutral as quickly as you can. Pull to the side of the road and stop. Remove the float bowl lids and examine how much fuel is inside. Each bowl should be about 1/2 to 2/3 full of fuel. If they have less fuel or no fuel you have a fuel delivery problem. It could be any number of things... plugged pickup in the tank, perforated pump diaphragm, plugged filter, plugged float valves....

As TR-Beg suggested, another test is to tip a thimble of fuel into each carb throat and try to start the engine. If it runs very briefly and stops you know you have restricted or blocked fuel flow.
Click to expand...

I'm convinced it's fuel and you're right. My float bowls were 40% full at best and I saw some debris on the bottom of each bowl. I'll check the tank also, though that's always so messy--I've procrastinated there.
 
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