Exhaust Popping After Cold Start

PostPost by: Lotus49 » Sun Jul 30, 2023 12:07 am

Hello All,

I just recently got a 1974 Elan Plus 2 and notice that after I start the car (cold), there's some popping in the exhaust for the first few minutes. It's sporadic and by itself not too alarming. But since I'm not very knowledgeable about cars this old, I wanted to double check with those smarter than me to see if this popping is indicative of a bigger problem. Thanks!
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PostPost by: h20hamelan » Sun Jul 30, 2023 12:09 am

how is the timing?
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PostPost by: Lotus49 » Sun Jul 30, 2023 12:23 am

h20hamelan wrote:how is the timing?


I have no idea how to answer that question. I'm not very knowledgeable about the intricate details on how cars work.

I'm guessing that you might be asking how smooth the engine runs? Once fully started with fuel flowing, it seems decent. No concerns there.
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PostPost by: USA64 » Sun Jul 30, 2023 2:34 pm

It would seem that someone other than you services your car. Have you asked them?
We are supposed to be having fun, are we not?
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PostPost by: Lotus49 » Sun Jul 30, 2023 3:10 pm

USA64 wrote:It would seem that someone other than you services your car. Have you asked them?


I've owned the car just shy of 4 weeks.
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PostPost by: gjz30075 » Mon Jul 31, 2023 9:23 am

What carburettor type? If the choke is working, does it change with a different choke position? Sounds like
a mixture issue, probably minor, since you indicated it runs fine after warm up.
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PostPost by: Lotus49 » Mon Jul 31, 2023 4:14 pm

gjz30075 wrote:What carburettor type? If the choke is working, does it change with a different choke position? Sounds like
a mixture issue, probably minor, since you indicated it runs fine after warm up.


My car has Delloroto carbs.

I have not been using the choke since the temperature is quite warm. Is this something I should use regardless of ambient temp? How much choke should be used in such cases?

Thank you.
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PostPost by: gjz30075 » Mon Jul 31, 2023 4:28 pm

I have Webers (similar) and have never used the choke in any ambient temperature. But simply
for diagnostic purposes, simply pull the choke when it is popping to see what difference it could make.
If the popping subsides, then you know the mixture is too lean. How does the car drive?
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PostPost by: Lotus49 » Mon Jul 31, 2023 4:38 pm

gjz30075 wrote:I have Webers (similar) and have never used the choke in any ambient temperature. But simply
for diagnostic purposes, simply pull the choke when it is popping to see what difference it could make.
If the popping subsides, then you know the mixture is too lean. How does the car drive?


Thanks for the suggestion. I'll do that.

Funny question about asking how it drives. Long story- I can't drive it due to a wheel issue. There's a 4-5 page thread on that elsewhere in the forum.

Before my wheel issue I drove it for about 20 or 30 miles. It seems to vibrate a lot at low RPM's at times, but the engine revs well and I enjoyed driving it while I could. I wonder if the vibration at low speed is due to motor mounts weakening? I'm not sure.
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