Hello i just bought this dodge truck its a 1994 dodge ram 1500 2x4 5.2L 318 motor in the morning when the motor is 100% cold, when it is started it runs real rough back fires, splutters, shudders, shakes and when you go to put it in gear or in reverse, the motor will stall out, sometimes it will even stall if you let it just sit and idle rough. now the weird thing if you let the engine sit and warm up to about 210-230 degrees the motor will smooth out perfectly and run strong. i have replaced the spark plugs, spark plug wires,Idle air controll valve, coolant temp. sensor, i have rented the fuel pressure guage and when i hooked it to the schrader valve and turned the truck on the pressure was around 48-49.5 lbs of pressure i dont know if that is to high or what. someone also told me it is possible to be a fuel pressure regulator, iv looked all over the fuel rail for this thing and can not find it anywhere is it located on the pump in the gask tank? someone else told me vacuum leak i sprayed carb cleaner around and it never reved up or choked, so im at a loss iv spent alot to try fix this thing i hope someone here knows how to fix it or has herd of this i am new to this forum i just made it to get help thanks alot
mat

 

Maybe try replacing the rotor and distributor cap, this may help smooth out the rough idling. Also, check your trans fluid and make sure its good. Also sounds like the truck is running hot between 210-230. Thats a little high I think, mine runs between 185-190. Just my .02 cents, keep us updated on anything else that changes. I sure more guys will be here soon to chime in....

 

could be a clogged cat.

 

it aint the cat, either the fuel pressure reg. like u said or the pump itsself. the pressure should be around 55 i do believe.

 

Spec fuel pressure is 35-45psi in the Haynes manual, typical is right around 49psi. What the OP reports is just fine.