Have you checked vaccum? A flat old worn camshaft could cause this. Burnt valves? Is it possible that the clutch is slipping? A bad TFI ignition modual could send a goofy signal. Clogged cat.

I wish I was there as I love a challenge. You got new plugs, clutch, wires, rotor, cap, fluids. air cleaner. I belie the O2 sensor could cause this but it would mostl ikely throw a trouble code. Possibly dirty injectors, fuel pressure regulator?

Start testin and guessin.

 

here's an idea. let's just pull the 300 out and drop in a SBC!

 

Boooo! Hissssssssss! Shame on you, 6Cyl!!

 

I did have 31s on my 95, 300, 5 speed, and 3.08 ratio. Performance improved when i put on the stock 235/75/15s.
I agree with many other posters that the 3.55 should be the standard gear. The only good thing about the 3.08 is it allows the 300 to cruise above 75 mph. I have not noticed any change in gas mileage between the two in mixed suburban and highway driving.
YMMV
regards
rikard

 

Yeah bill thats a bit racy.

 

what, you guys don't like the chebby idea? how about a mighty HEMI!?

got a HEMI!?

 

Chrysler hasent made anything worth owning in 30 years. Id rather push a chevy then drive a dodge. At least the wheels stay on a chevy.

 

screw it. let's put a 4bt Cummins in that wizznatch!

 

Hell yeah, six in a row with a diesel!
I want one of the small cat diesels in mine. My buddy says you can get them with a 460 bellhousing pattern. They make them as a drop in for a 370.

 

I meant the 4-cyl version. easier fit.

 

4BT = 4cyl, 6BT = 6cyl. Sadly enough, the 4BT would probably be a good engine, even for an F150. IIRC, it's what was put in some of the old bread trucks, which outweigh the F150 by a bit, if I'm not mistaken. Were you talkin' 426 Hemi or that crap they have now, 6cyl?

 

I've checked for vacuum leaks.
Ignition module, Idle Air sensor, and Mapp sensor are new(those three go out on these trucks faster than the fuel in the tank so I always replace them).
I don't know how to Check the injectors other than Working/Not Working.
The entire fuel system from the injectors back is new as I stated earlier.
The o2 sensor will be replaced with the exhaust, but as was stated it Should throw an emissions code if it was bad.
As far as Camshaft/Valves, it's possible but wouldn't those also cause rough idle/hard start?
That's one of the things that bugs me. It has a very smooth idle and starts easily.
The only reason I know for sure that the clutch isn't slipping(other than just knowing it isn't), is the fact that the tachometer doesn't rise.
THAT is what I mean by slow/sluggish acceleration. It tachs up slow in Bulldog, Very slow 2nd and 3rd, and might as well forget 4th no matter how hard you mash it. It revs up in neutral, but not while going through the gears(like when you mash the pedal in something in Overdrive on a steep hill, Nothing happens).
The only things I haven't had my hands on is checking OBD-I and the EGR system. Computer will get read sometime next week, and I'll dive into the EGR when I get a chance.
I can't quit till I figure it out, it's done made me mad now. If it turns out to just be a Gutless POS, it will go down in the books as the world's only bad 300. Then I'll just drop in a 460 and forget about it. I already have the 460 and the bellhousing for the NP435.

 

Injectors have to be cleaned professionaly. A few shops have the equipment to clean them. They can varnish up.
Make sure the person/company does a full spectrum test on it including cylinder dump tests and koer tests.
My guess is gearing thats a pretty lame gear. The 300 is not a speedy engine. likes 3.55s and up.

 

I've began noticing more often than not on either of mine, if I don't run fuel system cleaner / injector cleaner and do some other things, they don't get as good a mileage or perform very well - especially my Ford. You can get the codes read or read them with their loaner reader at most auto parts stores anymore and it's free. You will want to do the KOEO test FIRST, then do the running test. The KOEO test will tell you if there are any CM codes that need to be addressed. Once those are addressed and you clear the memory, then you can re-check KOEO, then do your KOER and all the other tests. I have the digital readout Equus reader for my Ford, came with a book, cost about $30. One of the best investments I've ever made. Also bought the cheapie for my Toyota, got tired of paying the stealership $60 or more a pop to find out I needed a new gas cap (my original locking cap was vandalized and it ended up leaking).

 

any of the hemi's. I saw a 500+ CI Hemi on tv (truckz?). yessah, all power. I wouldn't mind having a new heli under my hood tho.