Okay folks, I've got a problem w/ my 1997 Ram 1500, 5.9 liter engine. This past weekend I drove the truck a lot and everything ran fine. I'm at 100,000 miles. As I was driving to work, I noticed that the truck was having trouble staying at interstate speeds. In fact, within a few minutes I was down to 50 miles per hour and slowly losing power. I limped it along to the Dodge Dealer and in the process the 'Check Engine' light came on. As I pulled into the lot, I let it idle (which it did fine), no smoke or anything.
After the Dodge Dealer checked it, I needed a tuneup bad...had spark plugs failing, and the mechanic told me that a full tuneup and 'Throttle Body Cleaning' was in order. I bought the parts from him and later that night I installed 8 new spark plugs, wires, distributor cap, rotor button. After installing everything, the truck started right up and I took it out for a test drive. It absolutely ran like a scalded hound. Truck ran great, had all kinds of power that I had missed, just ran great, no missing or being under powered. 85 MPH was easy to get to.

I drove 40 miles today and it did great, but I still dropped it off to get the mechanic to clean the throttle body for me (I wasn't sure about this.) After this was finished, I picked it up, drove it fine for about 30 miles.

Soon though, I was losing power fast. No smoke at all, but the truck was just bogging down as I went on, and soon I was off the interstate and could just barely get to 30 MPH! I went through town, soon I could only get to 20 MPH, and I limped it on home to my house.

I got home, checked all 9 plug wires and they're all connected fine. I pulled 2 of the spark plugs and they were clean, looked brand new (not wet or rich from fuel). So I idled the truck and opened the throttle a little and it bogged down and seems starved for fuel.

I'm thinking it's probably a fuel pump, but wanted to get your alls advice and experiences. Again, even when I'm opening the throttle, there is no smoke and the spark plugs look brand new (Not black, wet with fuel, or anything).

Anyone care to give me an idea?

Thanks in advance.

 

do the plugs look like the mix went lean? this could be as simple as a clogged fuel filter.

 

IAC valve, fuel pump needs to be checked for adequate pressure, TPS, MAP sensor

 

I called the mechanic who cleaned the throttle body and initially told me I needed to do the full tuneup. He said that before he'd proceed and put any more money into it, he'd scan it. He said that it sounds like a clogged catalytic converter.
When I told him that the Check engine light was still on, he said that the fuel pump would not cause a code to be thrown and therefore set off the light. He suggested I bring it to a Dodge Dealer and get it scanned.

The problem is, I do not have enough power to get to his office (It's just too far from my house to limp it.) I may have to take it to another Dodge Dealer closer to my home, which will charge me a fee to scan it. I have also heard that AutoZone or some local auto part stores can scan for diagnostic codes, but it's a different system than what Dodge uses.

When I told the mechanic that I thought it was possibly a fuel pump going out, or possibly fuel filter, he said possible, but if it were his truck he'd scan first.

Makes me want to possibly just remove the catalytic converter...which I know is a No-No. Still thinking and planning, thanks for the information thus far.

 

The OBD II in your truck is just like all the rest ... it'll scan just fine.

The way it "boggs down" sounds like a clogged cat. Pull the front O2 sensor and hang it out of the way. See if it fixes your problem long enough to get a code pulled at the parts house.

 

removing the cat is a no-no?? uh-oh... i better put mine back on, lol

 

Okay folks, I got home from work yesterday evening, pulled the 'upstream' Oxygen sensor, and the truck immediately had more power...which told me that it was the clogged cat. I took it to my local muffler shop, got all kinds of looks as I drove up there!
He replaced the cat and this solved the problem. I just got it back a little bit ago, I'm getting ready to take it for another test run now.

He did not 'reset' the check engine light, so I am going to get that reset, and then check to make sure it's not throwing a code.

But, for the problem that I was having, it can all be credited to a clogged converter.

Thanks for all the info folks, I'll give another update after I've driven it more this weekend.

 

No worries and I'm glad that's fixed. In the future you can have that tested for flow for only $10 at your local muffler shop but since these cats should last for a long while you'll probably not need to that .

 

I took the truck on the interstate this morning and had to run about 40 miles, and eventually back. WOW, what a difference the truck drives with everything firing like it should. The power was great, the sound is even better.
The new converter is much less restrictive and the exhaust really sounds so much better. I have duals on it after the cat coming out of a 40 series Flowmaster muffler. Well now it really rumbles.

I let it idle and climbed under it again to check for any air leaks around the welds, but there aren't any.

Thanks again for the helpful info, folks.