Isuzu rodeo

i have 1994 izusu rodeo with about 148,000 miles on it recently it has developed an interesting problem when accelerating the engine will only reach about 4,000 rpms at that point it almost sounds like a gate or something was opened and engine bogs down it is a v-6 red line on the tach is 6,500 rpmsit used to reve up to 5-5,500 no problem i am hoping maybe fuel filter any ideas

Well either a plugged fuel filter or a weak fuel pump. Do the fuel filter first. It’s easier.

Tester

thanks thats my plan i just have to find it off to the manual i go because of course it is not somewhere oppivous

May not be but check throttle cable, linkage all the way to motor.
May not be opening all the way.

Too much back pressure in the exhaust system is possible. Sometimes debris can get in the exhaust. Mice and critters can make nests if the vehicle was sitting unused for a while. The muffler could be falling apart internally, or the cataylitic converter can be bad. Is “check engine” light on?

it does not have the check engine light on. but muffler has sounded different shortly before this began happening i am changing the fuel filter tommorow if no improvement the muffler is my next inspection Thanks

On this truck, the check engine light won’t come on for a plugged converter. Considering that it coincided with a change in exhaust tone, that’d be what my money is on.