1996 GMC sierra bogs down under load

[rdmorin]

i own a 1996 sierra i had a problem with the engine bogging down under load i found a bad wire and on #4 cylinder wich melted imto the distributer,,,,,,,,,well i changed wires and cap/rotor button along with plugs . new air filter also ,,,,well truck still bogs down changed EGR valve too . well then changed fuel pump and filter truck still bogs down when warm and under load i have no fault codes and left scratching my head the engine is a 4.3 with a 5 speed tranny

[snoman]

i own a 1996 sierra i had a problem with the engine bogging down under load i found a bad wire and on #4 cylinder wich melted imto the distributer,,,,,,,,,well i changed wires and cap/rotor button along with plugs . new air filter also ,,,,well truck still bogs down changed EGR valve too . well then changed fuel pump and filter truck still bogs down when warm and under load i have no fault codes and left scratching my head the engine is a 4.3 with a 5 speed tranny

 

<{POST_SNAPBACK}>

 

 

 

 

Under what kinda of load/RPM and what tempature conditions too?

[rdmorin]

i own a 1996 sierra i had a problem with the engine bogging down under load i found a bad wire and on #4 cylinder wich melted imto the distributer,,,,,,,,,well i changed wires and cap/rotor button along with plugs . new air filter also ,,,,well truck still bogs down changed EGR valve too . well then changed fuel pump and filter truck still bogs down when warm and under load i have no fault codes and left scratching my head the engine is a 4.3 with a 5 speed tranny

 

<{POST_SNAPBACK}>

 

 

 

 

Under what kinda of load/RPM and what tempature conditions too?

 

<{POST_SNAPBACK}>

 

 

 

any temp and around 200 to 2500 rpms

[rdmorin]

i own a 1996 sierra i had a problem with the engine bogging down under load i found a bad wire and on #4 cylinder wich melted imto the distributer,,,,,,,,,well i changed wires and cap/rotor button along with plugs . new air filter also ,,,,well truck still bogs down changed EGR valve too . well then changed fuel pump and filter truck still bogs down when warm and under load i have no fault codes and left scratching my head the engine is a 4.3 with a 5 speed tranny

 

<{POST_SNAPBACK}>

 

 

 

 

Under what kinda of load/RPM and what tempature conditions too?

 

<{POST_SNAPBACK}>

 

 

 

any temp and around 200 to 2500 rpms

 

<{POST_SNAPBACK}>

 

 

 

[rdmorin]

2000 to 2500 rpms

[rdmorin]

i own a 1996 sierra i had a problem with the engine bogging down under load i found a bad wire and on #4 cylinder wich melted imto the distributer,,,,,,,,,well i changed wires and cap/rotor button along with plugs . new air filter also ,,,,well truck still bogs down changed EGR valve too . well then changed fuel pump and filter truck still bogs down when warm and under load i have no fault codes and left scratching my head the engine is a 4.3 with a 5 speed tranny

 

<{POST_SNAPBACK}>

 

 

 

also this truck has a 159,000 miles on it

[Rookie]

Hook up a vacume gauge and goose the gas, look at the gauge and if it is slow to react and return to the idle spot. your cats are clogged.

 

Just my .02

[ChevyTech007]

your cats are clogged.

Thats what I'm thinking also. Do a back pressure test.

[rdmorin]

where am i hooking up the vacuum gage ? no vacuum hoses also i had my mechanic check that out he said everything is ok

[rdmorin]

well last night i put sea foam in the gas tank and will let that wash thru the system hopefully that works

[ChevyTech007]

i had my mechanic check that out he said everything is ok

Did he do a back pressure test on the exhaust system? That is the best way to rule out a clogged cat, which is what it sounds like you have.