1998 Dodge Ram 1500 2wd 5.2L 127K miles...owned it for about 2 months

Ok I have been thru pages and pages trying to figure out what could be the cause to this. The biggest problem is there are a lot of people who have similar problems as I but they never respond to their thread on how they fixed it all. Here are my issues: Engine Codes: P0138, P0300, P0302, P0308.

The best way I can describe this problem is I first noticed it cruising around town. I was going about 35mph and the truck just seemed like I was letting off the throttle. It got worse over time (I assumed it was the 02 sensor) and I noticed that if I punched the gas pedal, the thing would basically choke out like it wasn't getting enough fuel.

First thing I did was replace the o2 sensor right before the cat. I got a bosch o2 sensor and had to extend the wires, but a new one is in. I also cleaned the one after the cat real well w/ CRC cleaner so I think those are good to go.
I have replaced: Distributor, rotor, TPS, battery
I have checked: ICM, all wires, all plugs
While I had all of these problems, I found that my water pump was also bad so while it wasn't running, I changed that out along w/ a new serpentine belt. Today when I went to fire it up, it wouldn't start. I had it started up and running around before I decided to do the water pump install...and I haven't changed or checked any electrical stuff since then so y no restart? I know I got all hooked back up right and the belt is properly aligned.
So now it seems that no fuel is getting to the engine, so in attempts to start it, I pushed the pedal down a couple of times and smelled fuel, so I know its getting to the engine. I am going to try the rubber hammer to the bottom of the tank tonite and see if it won't fire up that way...

After reading up, it sounds like I should pull my throttle body off and check that, clean up the IAC sensor, and MAP sensor, and throttle body real well. I am really hoping it isn't my fuel pump thats the issue ( I hear it kick on when I turn the key) I haven't checked the pressure in the lines yet because the truck is somewhat dead to say the least.

Anyone have any ideas?

Cliffnotes.. under heavy acceleration, truck would choke out Engine Codes P0138, P0300, P0302, P0308, now truck won't start.....possible sensor problem still or fuel pump perhaps?

Thanks in advance for any replies...this Ram has been sitting now for about 2 weeks.

 

Check out your coils wires. Especially the ones going into the coil at the bottom. I've read of people kocking/pinching these wires when doing work on the water pump. It could be a possibility of why it won't start now. Just a thought of something to check. Good Luck.

 

I checked the coil this am and it all seemed to be hooked up right. Its nice that its so easy to check! I never got around to the sensors though so I will check them tonite but I am still open to any opinions as to what else I am missing..?
Thanks all

 

Sounds for all the world like a clogged cat to me.

 

10-4 on the catalytic converter, but it could also be the coil itself. One of my 318 vans had the same deal. It would run fine at idle or low rpms in gear, but, when you goosed the throttle, the coil didn't have the *** to burn the stuff up. This of course not being able to recite the codes. Ithink the three are for random, cylinder 2, and cylinder 8 misfires (p300, p302, and p308), and that the other (p138) is either rich or lean. I am guessing lean though. I will look it up and post back. You probably put your foot to the pedal, floodthe chambers, and ,when your brand spanking new 02 sensor sees all that carbon it leans the motor way out. Then when you run for a few at idle the fuel maps haven't had a chance to come back, and you get alean code. If you put a scanner on it you will probably see fuel tirms of -30 when you step on the gas and +30 after you go back to idle.

 

P138 is high voltage to the the downstream o2 sensor (bank 1 sensor 2). Maybe you cleaned it too good? That sensor will throw codes, but won't affect how the motor runs. I would check the cat, and then thecoil.

 

Update: Problem finally fixed
Ok I went home last nite and had a good look at the coil. The actual electrical connection on the bottom had a busted tab so the actual electrical harness had no way of staying hooked into the coil. I had my friend hold the coil plug in as I attempted to start it and sure enough it started to pop like it wanted to go...but I found that the wire coming from the coil heading to the actual distributor was burned up. I replaced that, along w/ all of the other wires, and bought a new coil, and cleaned up the MAP and IAC sensors real well and presto...truck fired right up and that bog down hesitation was now gone. I haven't driven it around since the fix cause I got it running so late last nite but I think the O2 sensors are good to go as well.
It took about 2 weeks and the following was replaced: Coil, wires, cap, rotor, battery, TPS, and plugs but success at last. Half the stuff I replaced didn't need it but thats ok...I know that stuff is good now.
Thanks to all for their input....couldn't have done it w/out the help of this forum

High five!

 

High five back. Good job. Just goes to to show, when you think you've dug all the way, dig a little further.

 

I went thru similar p300 and p3xx codes on my 2000 Ram 1500 and my son's 2001 Dakota and both ended up being clogged up cats. A quick check to find out whether you have a clogged cat is to remove the pre-cat 02 sensor and take it out for a spin. In both my cases, the engines 3.9 on the Dak and 5.2 on the 1500 would stumble and bog down at anything above 3200 rpm. The Dakota one happened about a year ago and we went thru a lot of suggested causes before finding the true cause. (4 02 sensors, plugs, wires, cap, rotor, coil and then the fuel pump.) With the Ram 1500 I went straight to the source and put in a magnaflow cat to go with the magnaflow cat back duels that I already had on. The 5.2 really woke up today after the new cat was installed and is showing more get up than it had when I bought it 6 months ago. Now hopefully my gas milage will creep up as well.