Stromberg enigma

Tips and help requests for your cars mechanics. points gaps, timming settings all those sorts of things

Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 11:52 am

I thought my fuel problem was the pump but it seems to be the carb, Stromberg was new last year. Needle valve isn't sticking. I can start the car but as soon as the throttle opens it dies. diaphragm seems fine and new.
I am stumped. This was running fine and then just stopped? Any ideas.
Mike
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Re: Stromberg enigma

Postby 1972nail » Tue Aug 13, 2019 11:57 am

Check-
Manifold bolts are tight.
Servo pipe and servo itself aren't leaking
Piston isn't stuck and lifts easily
Jet isn't blocked
Needle is dropping centrally into the jet.
Hmmm.....
Check -
Spark is good
Timing
Points or electronic module are earthing properly
Condition of coil and all LT and HT connections.
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Re: Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 12:06 pm

Checked the manifold first, no servo, piston is working easily, going to have the bottom off to check the jet, checked the timing earlier and the valve clearances all 0.008", checked the dizzy and all looks good. I think I will put a plug check tool to see the spark.
I think I have covered all the basics, next I might just try a Weber I have to see what happens if I can't sort this.
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Re: Stromberg enigma

Postby Colin » Tue Aug 13, 2019 12:34 pm

Having checked everything listed it sounds like the mixture might be too weak.

With the air box removed and the engine ticking over use your finger to lift the carb piston slightly. If the engine dies when you do this it's running too weak.

Switch off and adjust the mixture a quarter turn and try again.

When the mixture is correct the engine note will rise and then settle down when you lift the piston slightly.

https://www.howacarworks.com/fuel-syste ... arburettor
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Re: Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 2:06 pm

Hi, Thanks for the help, mixture is ok and this did just happen but following on from David I put a laser plug tester on and found the spark died at probably about 1500 revs, it has electronic ignition and all looks ok in the dizzy, just got to trace this problem now.
Mike
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Re: Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 2:45 pm

Changed the rotor arm and cap and can now rev it but it now dies when I lift my foot. Just can't win.
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Re: Stromberg enigma

Postby 1972nail » Tue Aug 13, 2019 3:20 pm

Seems to me that there is an ignition problem rather than fuel..... If you have a spare coil and leads swap them over.
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Re: Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 3:36 pm

Gone worse, tried another electronic unit, now no spark. Also tried another coil. Think I will go back to points if I can remember how they are wired.
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Re: Stromberg enigma

Postby 1972nail » Tue Aug 13, 2019 4:15 pm

There are some after market OHV caps and rotors that were not that well made. I don't know what exactly was wrong with them but the connection between the rotor and the centre contact was very poor. Might be worth looking at various combinations as a possibility.
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Re: Stromberg enigma

Postby Mike Attew » Tue Aug 13, 2019 9:42 pm

Some caps had a slightly larger lip diametre, I have several and went through them with a vernier so I had a good fit with rotor, changed to points after it failed to run with 2 sets of electronic ignition. Took it out tonight with no problems so I did something right but not really sure what. This was a strange one. Learning curve there don't go for the obvious and I wouldn't have thought electrics until you said Dave.
Also my set of plug checkers that I bought late 70's have come in useful again, they are the ones you connect to the top of the plug and the lead goes on top, they then flash when the plug fires.
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