Starting woes

[HQentity]

Heres one for you lovely people please!

My car struggles to start when she hasn't been used - usually it takes a good day or so to get 'bad'. Once she's reached that point, it will take 2-3 10 second attempts at starting.

Often she'll run on one carb for a good 3-4 seconds before finally running well, and once that point is reached, its like there was never a problem.

I can't find any leaks, I've tightened up as many fuel lines as I can see, Theres fuel in both the float chambers and the jets are 2-3 months old. Any suggestions?

[GTS290N]

OK, My answer is a bit off the wall.......
My car is the same, well for starting anyway, once the engine catches there's no problem.
I reckon my battery is goosed.
Why?
If I strap one of those lithium battery jump-starters across the battery the engine fires almost immediately - no cranking (as long as I have the choke out obviously). I reckon cranking the engine isn't leaving enough in the battery for the ignition.
I had a similar problem 37 years ago on my original dolly due to a bad battery connection..........
Can you borrow a jump-start pack? That would be a 30 second yes or no elimination!

[HQentity]

I don't think its the battery, because thats pretty new too, and all the water inside is fine. I have jump leads, so will have a go at jumping it at some point and see what happens though?

[soe8m]

Is your ignition ballast system working correctly?

Jeroen

[dollyman]

I have exactly the same problem, and on mine it is fuel draining back to the tank or evaporating? It gets worse the longer i leave it I also have two triumph big six's that are the same but they have a primer on the pump, and when primed start fine

Tony.

[MIG Wielder]

Hi Kyle, I think you can eliminate choke operation problems. Both jets seem to be lowering nicely, and the oil level in the carb; pistons was O.K.
Did you check the fuel level in the float chambers after a long time ( say 3-4 days ). If one is low, that would be diagnostic for a leak from the jet.
There used to be a product on the market called " Eazy start " . It was basically a highly volatile organic compound ( ether I think ). If it starts straight away with a squirt of that, then it is most likely a fuel related problem.
As Jeroen says, check the ballast resistor is switching out correctly when the starter is operated.
Replacing the breather hoses may make a difference as well.
What do the spark-plugs look like btw ?

Tony.

[HQentity]

If there is fuel in the float chambers, is there any reason it wouldn't be getting to the engine? I will run a few tests when I get chance over the next week, and see if the plugs are getting wet, and see if those hoses improve things. When i originally checked, both the float chambers looked full.

How do I check the ignition ballast system please? I feel like its fuel, simply because if the car has been started less than a day ago, it's not a problem?

Dollyman, is it perhaps something to do with the fuel pump/filter your end, letting it flow back?

[dollyman]

I think you are right Kyle, i really should have a look at it. The fact it always starts eventually is why i have not bothered But i will do somethning in the spring as it will end up needing a new starter

Tony.

[HQentity]

My neighbours already hate me waking them up normally, let alone now she doesn't start! hence the urgency my end haha! Best of luck sorting it!

[dollyman]

Hi Kyle, i will let you when i sort it, luckily i dont have any neighbours close by

Tony.

[HQentity]

Ok, so I left the car as long as I could ( 36 hours ish), and replaced the breather hoses. I had a look at the float chambers and they were both exactly the same (about half full without the floats), and the plugs were ok, if a little white. I richened up the mixture a few flats, pulled the choke, primed with 3-4 pumps of my foot and... nothing. Still wouldn't start for a good 20 seconds? I looked at the plugs again, dry as a bone.

What needs to work to get fuel from the float chambers to the engine?

Tony I think I might as well send that jet back because I don't think it's only one jet now, unless its worth replacing both?! But they're so new??

[soe8m]

Priming has no use with SU or Stromberg carbs as the only thing you do is opening and closing the throttle valve.

For checking the ballast sytem the best is to test with a handy helper. One does start and the other checks the voltage on the resistor, the bypass wire or the coil.

How is the valve play? Sometimes it can happen that the valve play is too tight and then you will have the same symptomes. One valve too tight can cause the same running on one carb for a few seconds. Your engine can be just in the stadium difficult to start but just runs fine and after a while it starts running poorly also because of the wrong valveplay. My cars run on LPG and not all (Volvo) (2500) have converted heads and valves and seats do wear more on conventional lpg systems. As i'm very lazy at maintenance difficult starting does automatically notice me to adjust the valve play again.

Jeroen

[dollyman]

Hi Kyle, I took Tony's advise (above) with easy start but used brake cleaner, result was instant start although it stopped again as soon as it had eaten the brake cleaner So i know mine is fuel related It does allow the oil to get around first though

Tony.

[Carledo]

It seems to me that you have identified and ignored the problem!

On removal of the float chamber lids, both fuel levels were 1/2 way up, when they should have been higher. To work correctly the float chambers must be FULL as this directly affects how far up the JET the fuel is too, too low and there is insufficient vacuum at cranking speed to suck fuel up the jets and thus into the engine. Thus the engine won't fire until the fuel pump has replenished the float chamber level. If you also have run back in the fuel lines over time as most cars operating this sort of fuel system do, this can take a while of cranking to accomplish. The sloppy, missy, initial running is because it will start on 1 carb as soon as the float level is high enough, then run roughly until the second chamber is also full (it would be a miracle if both leaked exactly the same amount!)

So what you are looking for is a VERY small fuel leak from the float chambers and, since the jets are new, this more or less HAS to be at the seal where the jet feed pipes screw into the bottom of the float chambers. It doesn't need to be much more than a slight seep, just enough to lower the float levels over a period of time.

The other cure, is to fit an electric fuel pump, which can prime the carbs WITHOUT cranking, just by switching on the ignition! (ducks for cover after suggesting such a non standard bodge of a fix!)

Steve

[dollyman]

That thought had crossed my mind Steve After all it is reversable. I dont really want to play with mine as when i does start it runs great with good economy as well 36mpg on a run It sounds a good idea though for Kyle as his is a daily driver?

Tony.