Hello All,

I have been on the forum for a while with my Ram but I just bought a 1999 dodge Durango 5.9l 2wd so this is my first durango post.

The previous owner didn't take to much care of the D so I'm tuning her up and getting her back in tip-top shape.

So far I have replaced the IAC, Spark Plugs, Cap and rotor(with Accel) Cold air intake, air filter, Oil and filter change, cleaned the throttle bodies, and throttle body gasket.

The problem I having now is she keeps throwing the code P0505 but I feel like I have attended all the problems that could cause this. Also, When I start her, she has a rougher start and vibrates in the truck a little bit. And when I hit about 40 MPH it feels like I am driving or little tiny speed bumps because she starts riding rougher.

I like this durango very much but I want her to last a while so any input on where to look or what to do would be very appreciated. Thanks all.

 

what plugs did you use?? our trucks like the copper core champions the best... also check the TPS and the plenuim gasket..

thats what comes to mind... others will chime in with more ideas...

 

I did some searching ( I know y'all like that) and used the copper plugs from champion and the cap has brass tips. How exactly would I check the TPS and where is the plenuim gasket?

 

How to test the TPS:
1

Open the hood of your vehicle and locate the TPS in the engine compartment. Its most common location is on the outside--to the right or left--of the throttle body or carburetor plate shaft. Here you will see a small black box with three wires coming out from its electrical connector.
2

Unplug the TPS electrical connector. Turn on the ignition switch, but do not start the engine. Using a voltmeter, probe the connector’s terminals coming from the computer side to test for supply voltage. Touch the negative lead to the connector’s terminal ground--most likely the black wire--and the meter’s positive or red lead to the connector’s terminal reference voltage wire, a blue or gray color wire. Your meter should read a steady 5.0 volts at the terminal. If you don’t receive this voltage reading, there is an open or short in the supply wire. Turn off the ignition switch and plug the electrical connector back to the TPS.
3

Test the TPS for signal voltage to the computer. Insert a pin through the ground wire and another pin through the signal voltage wire and connect the voltmeter probes to the pins using alligator clips. Start the engine. As you manually open and close the throttle plate, watch the voltage readings at the meter. The voltage should gradually increase from 1 to 5 volts and back to 1 volt. If you see erratic movement or no movement of voltage signal, replace the TPS. Turn off the engine.
4

Test the TPS’ resistance. This is an alternate method to test a TPS equipped with a variable resistor. Unplug the TPS electrical connection. Set your multimeter to ohms. Connect the ohmmeter probes to the sensor’s supply and signal wire contacts. Manually open and close the throttle plate and watch the resistance reading at the meter. The resistance should gradually increase and decrease as you open and close the throttle plate. If there is an erratic resistance change, no change, or no resistance at all, replace the TPS.
5

Adjust the TPS. Some sensors need to be adjusted from time to time. They are mounted with a couple of screws that allow the sensor to be rotated for adjustment. Loosen the mounting screws. With the ohmmeter connected as described in Step 4, rotate the sensor until you obtain the resistance specified in your vehicle service manual. Tighten the mounting screws and check the sensor’s resistance as described in Step 4.
6

Plug in the TPS electrical connector, start your engine and test for performance.

now as the plenium gasket as i understand it (correct me if it wrong) is the gasket under the intake... Take off you air hat and open the butterfly up on the throttle body.. shine a flashlight down there.. if you see oil you need to replace the gasket.

 

Well you don't have to start the engine to get the power to enact the resistor in the TPS. You simply just tun the key on and measure. You can open the throttle plate and it will react as it would being running.

You cannot adjust the TPS unless you remove the brass sleeves on the TPS. Now you can tune the TPS buy getting a larger then bore sized bit and locking onto the brass insert and crank her up. It will spin until it heats up and pushes the brass sleeve out. Then you get a washer large enough to cover the hole and you can adjust it to 0.7 - 0.75 volts and crank it down, but not too hard or you will damage the TPS because the inserts are now gone.. Double check the volts to ensure it didn't move. Reset the PCM and enjoy a nice crisp throttle response and great pickup.

You are correct on the plenum gasket. If you see just oil vapor then it should be ok, but puddles of oil is a bad gasket.

 

Here's an update and a few more questions.

I pulled the hat off this morning and took a look down in there. I would say there are pools of oil but there you can see some oil shining back at me. But on thing I notice and wanted to ask about.

It would appear that when I installed the last throttle body gasket that it is offset just a little bit. Meaning, when I look down the throttle bodies, I can see part of the gasket. Could this be causing any of these problems or would that not really affect anything that much?

Thanks once again for the input and help.

 

That tb gasket wouldn't cause the problems you described, however that plenum gasket getting oil into the cylinder will. It needs to be replaced. Thanks for searching then asking, it makes it a lot easier for us to explain things when you have an idea of whats going on first.

 

Alright well I'm a little confused at this point. Is it safe to say that the plenum gasket is also known as the intake manifold gasket?

 

Yes, I've heard it referred to as the intake plenum gasket as well.