96 Ram loses power

#1

I have a 96 Dodge Ram 5.2L gas engine that has lost power. It starts up and runs rough when cold, but after it?s warmed up it idles smooth. Once I give it a little bit of throttle, it starts to cough, sputter, and bog down. The only times that I have ever seen this, the either the timing was off, or the fuel filter is plugged. I checked the timing chain by lining up the crank at TDC and looking at the rotor position, which looks to be dead on. The truck does not seem to have a serviceable fuel filter, but I checked the pressure, and I get about 45 psi on my gauge. It doesn?t change as I rev up the engine.



Also, I changed the plugs, wires, cap, and rotor, but I still have the same problem. Has anyone else come across this sort of thing before?



Thanks,

Ken

#2

What do you want? Do you a list of parts to match the symptoms? Ok, engine coolant temperature sensor (cts), throttle position sensor (tps).

#3

Actually, I was hoping that someone had come across this before, and what they did to fix it. I’m getting good readings out of the cts and tps.

Thanks,
Ken

#4

Ken, did you solve this problem? I’ve got a 98 Ram 5.2 that bogs down under load. In park it revs fine. 50# of fuel pressure. had to replace cat. Thanks, Andyhd

#5

Plenum gasket. It’s actually a recall, but it sounds like the replacement doesn’t last anyway, not worth the time…(?) You need either the Hughes or APS replacement. Shop cost likely around 700 P+L. Or it sounds like it’s not hard to do yourself if you have a day to put into it. You’re right, ‘fuel filter not servicable’ Groan. And while you’re in there there are some other items to replace, waterpump bypass hose, O rings etc. Also there are supposed to be some simple mods for the throttle body while it’s off. Start googling plenum gasket- there are loads of info out there for these trucks. I’m going through the same issue, just made the same repairs you did and now deciding between DIY or paying for the shop hmmm… Mine’s the 5.9, and I find the throttle position sensor suspicious, but not the cause- my problem is heavy load, say driving 100KHr in OD into a head wind, almost impossible! Idles ok, pick up off the line is gutless but smooth, it’s just under that load she pops and has no power.

#6

No, I haven’t solved this yet. It’s mostly been sitting. I did notice that I’m getting random mis-fire and cylinder 3 mis-fire codes. I’ll disconnect the cat this weekend and see if that helps. As for the plenum gasket, would you notice this as an external vacuum leak? What are the tests that I can use to diagnose that? I was also wondering if the idle air control motor could be stuck open? Would that cause a mis-fire off idle? In park but off idle is when I see the worst bogging down and rough running like a cylinder is not hitting. Compression is good on all cylinders.

Thanks,
Ken