I have a 93 D150 3.18 Auto 125k miles..

Truck has always ran perfect, no complaints. But two years ago the feul pump went south so I replaced it.. it's ran fine ever since.

Recently it started running rough just like it did when the old feul pump went out. It would have lousy power, pop under hard loads.

Put a new feul pump in and it's still doing the same thing.

I have done a tune up.. plugs wires cap rotor pickupmodule in dist. feul filter new map and problem still persists.

Sometimes it will drive into town fine with no probems, other times, especially during hard load it will want to run like crap and miss and pop. let off and it clears up.

Do these trucks have any common problems I should be looking for.. i'm about lost with it!

Any help is appreciated!

RJ

 

Have you checked for any vacuum leaks?

 

Have you checked for codes ? with it popping and not doing it all the time my guess would be a egr vavle,But thats just a guess check codes

 

the 5.2 has issues with bushing in block under distributor check for end play in distributor shaft also try switching pcm with arunning truck to eliminate that. i just went through same stuff ended up being pcm.

 

plenum gasket?? look down the throttle body if you see wet like oil,its plenum gasket,a noted problem with the 92-up 318 magnum. good luck

 

No check engine light has ever come on, even when it runs rough.

To test for egr, can i unplug vac from it and drive it around and see if it clears up to rule it out?

I will check for oil in my plenum as well.

As for vac leaks, no obvious ones that carb clean has detected.

As for a pcm problem, i surely hope not, but ill do all others first.

 

Most codes do not light the check engine light. The only way to eliminate all possible problems associated with the EGR is to remove the EGR temporarily and blank off the opening to test.