backfire problem

[jrhemipete]

i got a issue on my dodge pickup...

everytime i let off the gas or its up high in the RPM and i let off to shift with the clutch it backfires about as loud as a shot gun i dunno what it would be anyone know?

[moparmussel]

sounds like you are sucking air into cyl through an exhaust leak.check manifold,exhaust manifold,doughnut gasket!

[ehostler]

A stretched timing chain will cause that problem, as well.

[jrhemipete]

i found a small hole on the Y pipe where the 2 manifolds down pipes meet.. as well as i noticed the entire pipe asselbly is kinda loose cuz i can shake it so if i tighten up them manifold bolts and get the exhaust tite.. then just mig weld the hole shut really quick that should fix it i hope....

[cutting torch]

If you have an air pump for emissions, the diverter valve could be bad.

torch

[jrhemipete]

no air pump

[cutting torch]

Just theorizing, but...... lean jetting on the main metering (making the exhaust run really hot), then rich idle jetting that loads the hot exhaust, then explodes in the pipes. Maybe?

torch

[jrhemipete]

wht i do know is that it smells like gas really bad in the xhaust it self it smells really bad

[cutting torch]

Well, if it runs rich, AND siphons air into the exhaust when you let off, that would do it. Once you fix the leaks, it should stop. I would lean it out a bit, too.

torch

[jrhemipete]

i kno how to lean out a 4 bbl but how due u lean a 2bbl on a 4.1/6 chevy engine :-x

i have no idea how to mess with that carb... what bout the fuel filter.. u think if that hasnt been changed in a while.. i mean its inside the carb and would be a B$%^$ to disconnect without breakin the line....