Afterfire pop?

This is the place to get help with technical matters concerning your M151 jeep

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rickf
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Location: Pemberton, NJ.

Re: Afterfire pop?

Post by rickf » January 31st, 2021, 5:43 pm

A backfire on deceleration is usually caused by a leak in the exhaust system close to the engine. Exhaust manifolds on these leak a lot but the one that usually causes the backfires is the gasket between the manifold and the front pipe. Leaning out the idle mixture is sure to give you the infamous M-151 flat spot at cruise speed.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Husker
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Re: Afterfire pop?

Post by Husker » February 22nd, 2021, 8:48 pm

It may have been an altitude thing I never had it occur beside the few times..... when I drove to work I don’t get it. But I generally drive with a tiny bit of choke depends on the day.
US Army Fort Belvoir

19XX M35 something. Sold......
1972 M151A2
1967 M416
On the hunt for an M1031

rickf
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Re: Afterfire pop?

Post by rickf » February 23rd, 2021, 10:40 am

The choke would just add to the problem if you have an exhaust leak. More unburned fuel in the exhaust and then you introduce oxygen into it as it comes out red hot and bang.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Mark
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Re: Afterfire pop?

Post by Mark » February 23rd, 2021, 11:17 am

I think the accelerator pump adds too much fuel to for the engine to burn so the excess goes in exhaust system?
mark


1968 m274A5
1960 m151
1981 m151A2
1964 m416
1971 m416

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