Miss under load

[Rangerdan2.3]

I just bought another Ranger, she is a 90 4cyl 5spd. Under load, it falls on its face prolly around a little over half throttle. It is not the plugs or wires, my guess is something in the fuel system. Also has a problem keeping freeway speeds and lacks power. there are fairly low miles on this rig(low100,000s). Just wondering if anyone had a similar problem before I go replacing everything?
Thanks
Dan

 

[Dave R]

Start with the fuel filter. If that doen't solve the problem, next I'd check the fuel pressure at the injector rail.

 

[jubangy]

Exact same problem on a 94 2.3l ended up replacing the muffler, both the bolts that bolt the exhaust donut together as they were coming loose, and I had to replace the tailpipe and hangers as the tailpipe was moving up inside the rear passenger fender effectively plugging it most of the way so it wasn't letting the engine throw enough exhaust. Also, I had never thought to check the air filter after all the mudding I used to do and when I did change it holy sh*t batman what a difference those extra parts make...

All in all the exhaust was the biggest problem and had the most bad effects associated with it from no power to crappy idle. My wife can not believe how much of a diference it is driving my truck now compared to the last 6 years. The thing that makes no sense to me is I changed the engine due to it not staying parked on any kind of incline (5 speed stick) the new engine did the same thing. For whatever reason now after I buttoned up the exhaust it stays just fine on the hills.