I was driving my 1996 1500 4x4 w/ 5.2L today...it ran fine with over 100miles traveled today. On the last leg of my driving this evening, however, it developed a poor engine running condition. The truck would barely manage 30mph, and eventually I limped it home at 15mph (tops).

Once at the house, I popped to hood to listen and look for signs of trouble. I could re-start the truck with no trouble. The fuel pump could be heard to prime and run, too. The battery connections were good and the air filter was not clean, but by no means was it clogged.

Basically, when I would give the truck gas (even in neutral) it would start bogging down at anything over 2000rpm. I didn't hear any arcing that might indicate a problem with the ignition wires, though it was raining this evening on the last leg of the drive. That said, it was raining this morning, too, and there was no issue.

I'll dig into this more in the coming days, but my initial thoughts are issues with spark or fuel, or maybe a clogged catalytic converter. The truck only has 48k miles, btw, so I'm surprised by the trouble. Another thought is that maybe there is a crack in the connecting hose between the in-tank fuel pump and the fitting at the top of the tank - that enough fuel can be pulled for certain engine speeds, but above that demand there is too much fuel leaking past cracks in the hose so the engine gets starved. I'll start checking things off the list as I get time to dig into it more, but suggestions or BTDT experiences would be appreciated.

BTW, if I have to drop the tank, then I'll go ahead and install the last of the stainless steel brake lines I have left to replace...the one from the brake master cylinder to the rear axle (which passes behind the gas tank). I had been waiting for the fuel pump to fail before replacing that line - as I had previously replaced it with a Bundyline brake line when it last failed a few years back, but then upgraded all the other lines to stainless steel when a brake line on the rear axle burst last Summer.

 

inspect the wires. sometimes they crack and then you get a miss every time. Mine cracked and I was getting stumbling.

ALSO, check your injector connections. if you can pull them off with a gentle pull, then you will get a missfire every time. I had that problem when replacing a wiring harness because an engine compartment fire. I was missing the small metal clips that go around the base of the injector connectors to keep a tight connection.

Got new connectors and the problem was solved.

BTW, this problem was on my 1996 dodge. So your truck has those same EV1 style injector connectors. They are 5 bucks a pop at www.fiveomotorsports.com you need tosplice them individually. Get some shrink tube and a mini torch lighter.

 

Remove the pre-cat O2 sensor from the pipe, and see if its attitude improves any.

 

Yeah it sounds like the cat is jacked

 

Removing that first O2 sensor sounds like a straightforward-enough check. I'll try that first.

 

Are these 5.2L's prone to clogging cat's in stock tune? What is the cause? Should I be looking for something else being out-of-whack if it turns out the cat is clogged?

I'm just surprised, I guess. ~48k miles and the cat can clog? ... The check engine light isn't lit, either, so nothing watched by the OBD-II system is indicating trouble.

Thanks for the help so far!

 

Parts are ordered...new cat and 2 new O2 sensors (Bosch 13275 generics that I will solder onto the old wires/connectors) and a bolt kit for the manifold to downpipe connections.

 

Still waiting for all the parts to arrive, but I did get a chance to disconnect the cat at the two exhaust header downpipe connections. I fired up the truck and it ran without hesitation or a drop in power once at higher revs, so looks like I'm on the right track with replacing the catalytic converter. Should be able to get that done this weekend.

BTW, I was surprised at how easily the bolts loosened up at that downpipe/manifold junction. I had sprayed them with PB blaster over the weekend, so maybe that helped. But, in general, the threads weren't as corroded/clogged as I thought they would be from experience with other bolts on the truck.

 

If you can, don't get the bosch O2 sensors. Get Denso, or NTK. The bosch fellers don't always work so well in our trucks.

 

Take a look through this thread for a potential cause of your clogged cat: https://dodgeforum.com/forum/2nd-gen...um-thread.html 48,000 is probably pretty low for plenum problems, but the age of your truck could be a factor too.