Hey guys, haven't been around for a while, as I've been quite busy with school and my truck has been running quite well until recently.

95 Ram 1500, 2 wheel drive 318 auto. Plugs, wires, distributor cap and rotor are about a year old and show no signs of damage.

Having trouble flooding when starting, misses BADLY when it's cold or if it idles too long at a red light. Smells like it's running ritch at start up and extended idle. After the engine warms to operating temperature the idling missfire gets signifigantly better and the gas smell pretty much goes away, but will miss a little if I sit at a red light too long. The idle is not too low.

Before the engine warms up it seems to have lost signifigant horse power, and will backfire with full throttle acceleration. (sounds to me like unburned fuel pouring through the engine and igniting in the exhaust?) Again, after it warms up it gets better, but does not dissappear entirely.

This started about a month ago with just a bit of a missfire at start up, but then went away after it ran a few minutes. It is getting worse quickly and I don't even know where to start. Any guesses?

I am not receiving any error codes about the engine. Only code 37 for the torque convertor, which I know is a seperate problem, and one I'm afraid will not be cheap or easy to fix on a college student budget. But if you guys have any suggestions for that one, I'm all ears as I can't afford to replace the truck right now. Maybe in a year when I graduate.

Help?
Thanks, Steve

 

Could be clogged cat or 02 sensor problem. But, You might also want to try cleaning the IAC and the TPS. Clean the whole TB for that matter. Actually , have you looked down the TB lately? You might have a blown plenum gasket.

 

didn't say mileage... maybe a slipped timing chain... off a gear now.

 

Just shy of 140,000. Original timing chain. To me, it doesn't make sense for the problem to get a little better when the engine comes up to operating temp if it is the timing chain. Or does it?

The cat is not rattling, so I don't think that's the problem. I looked, and the O2 sensor is still connected, but I don't know if there's a way to check and make sure it's not gone bad? I am not getting a Check Engine light either.

 

That timing chain was shot 80k ago. Not saying that's the reason for the miss, but it's done. When you pull the cover, you'll see why.

you can clean an O2 with electric parts cleaner and see if that helps.

A cat doesn't have to rattle to be bad. if a large part of the honeycomb breaks loose and turns sideways, it'll really block it up. I've seen pics of cats with a melted lump of goo in the center as a honeycomb.

 

When I park it, I hear a distinct clicking for several minutes in the cat area. Sounds like thermal contraction as it cools down. Is that a bad sign? How else can I check to see if the cat is gone bad?

Thanks for the help so far guys.

 

2 ways to test

Pressure test.

the exhaust should be hotter on the way out of the cat than on the way in.

 

3rd way to check is a good muffler shop........

 

clicking while cooling down is completely normal.

the overly rich smell makes me think a bad fuel injector dumping in too much gas.
i'd remove and inspect spark plugs, looking for one thats black or wet or significantly different from the others. if i found one, i'd replace that injector.
new injectors are a little expensive, i'd think one from any dodge 5.2/5.9 in the junk yard would be fine.

i don't think the overly rich smell has anything to do with throttle body, tps, or iac or cat.

o2 sensor - possibly

 

To check your cat, buy a vacuum gauge and hook it up to yer intake (preferably to the brake booster port). I bought mine for around $20. Let it get nice and warm first. hook it up, and using your fingers, open the butterfly to rev it up. Get to around 4k RPMs, then snap it shut, watching the gauge. If all is well, the vacuum will drop to near zero, climb as the engine speeds up, and then peak around 25 inches plus as you close it, then race back down. If it's clogged, as you slam it shut, it will go up little to none, then float back down. Hope this helps..