Please help --- New owner of a 1958 Austin Healey Sprite

[Newb]

Hello everyone, I'm a proud new owner of a 1958 Austin Healey Sprite. It is equipped with a 1275 BMC motor, 45 DCOE Weber, mild cam, tube header, Datsun 5-spd and front disk brakes.

I am having an issue with the RPMs upon start. It warms up fine to 160, but I have to give it gas the whole time. Then after a few minutes, it should settle at idle (1k RPMs?), but it sputters out and dies. Car was not driven much in the past 3 years. I filled tank with 91 Octane, but had about 2 or 3 gallons of old gas. Any ideas of what might be going on here? Where to start?

Very much appreciate any advice you may have!

Cheers!

Jerry A.

p.s. I have a short 2-min video posted to YouTube https://youtu.be/UK6EonBp-D0

 

[Trevor Jessie]

Check the plugs. If they are fouled, put in a clean set and see how it runs. Then check them again and see if they indicate a problem.

 

[DrEntropy]

Congrats on a great 'base' to work with! A well set up 1275 in a Spridget chassis is something really special.

Even from the inherently poor quality of YouTube audio, it's apparent that thing is running wildly over-rich down at low end rev's. Compound that with old fuel and it's no surprise it runs that way.

I'd be curious to know how the Weber is jetted. A 45 is kinda overkill for a mildly set up 1275. A 40 would be more than adequate.

The oil pressure indicated in the video seems a bit "lazy" on revving, idle is good but it should be closer to 60~70 PSI nearly instantly on revving to 2800~3500 RPM. A modified oil pump may be the reason, more volume at lower pressure. Hunt for Clive Trickey's books on that, Good explanations and illustrations.

By all means, do some plug swaps, invest in a pair of "ColourTune" tools to help set up idle jets and mixtures with that Weber. Another thing to look at is the choke pistons in the carbs. Make sure they're fully seated. If not, they can leak fuel past the idle circuit.

 

[Newb]

Thank you guys for the great insight. As I said, I really am new to the circuit and have everything to learn (from scratch). I am by no means "qualified" yet (or brave enough) to attempt tinkering on this beauty, but have an appointment with a well-qualified British repair shop in San Marcos -- not too far from me in Oceanside. The shop owner did warn me not to run it any longer, until he gets his hands on it, to minimize any potential (further) harm. Here is a pic of the sickly Sprite...

 

[DrEntropy]

The shop owner did warn me not to run it any longer, until he gets his hands on it, to minimize any potential (further) harm.

That alone gives an indication you may have a good place to take it. Keep us up on what goes on with it! Really curious as to what they have to say about the Weber jetting and the oil pressure. Be sure to show them your video.