[DeTomaso] Exhaust popping

[Mike Drew]

Fred,

You almost assuredly have an exhaust leak. Before you start monkeying with your carb, have somebody rev the car (in neutral!) while you stand alongside, or sit atop the gearbox listening for a metallic clicking sound (which would indicate a leak at one cylinder) or a coarse exhaust note (which would indicate a leak at the collector (or the presence of a Hall Pantera Big Bore exhaust system))

Sorry, couldn’t resist... :)

When you have an exhaust leak, under acceleration exhaust gases leak out at the location of the leak. When you lift off the throttle, a vacuum effect is created inside the exhaust system which draws in air from the outside. This air mixes with unburned fuel in the exhaust tract and ignites in the exhaust system, creating the popping noise you are hearing. 

New header and/or collector gaskets will probably sort you out. 

Let us know what you find out?

Cheers!

Mike

Sent from my iPad

> On Apr 4, 2020, at 19:00, fred <fred at creekspeak.com> wrote:
> 
>    When I back off of the accelerator,  the exhaust makes a popping noise.
>   It isn't  a backfire in the carb. Wonder if the noise is caused by way
>   too rich setting resulting in fuel detonating in the exhaust pipes. Car
>   is running uneven and I can smell gas inside the car. Do I need a carb
>   rebuild or ??? Please email me. Thanks in advance.  Fred
> 
>   Sent from Samsung tablet.
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