Recently i have noticed that when sitting at a stop light with your foot on the brake the car feels like it wants to slightly jump forward. (sorry tough to explain) also noticed when driving up a hill sometimes the car feels like it loses power for a split second, but when driving on flat grade that problem never arises.

Any ideas?

02 3.4L

 

Can you see changes in the rpms when these things are happening?

How many miles? On spark plugs? Fuel pump?

 

RPms jump slightly, but not much. Car has 230,000 Kilometers, not sure what that is in Miles?

I changed the plugs and wires 1 year ago, also fuel pump went a year ago, so the fuel pump is only 1 year old as well.

 

Throttle position sensor?

 

Sorry, i have no idea, what or where it is?

 

Maybe a Haynes or Chiltons would have a drawing. I think it's on the end of the shaft that the throttle plate swings on (in the air intake).

There are various other sensors that can cause problems like your's. Camshaft Position Sensor and MAP among others. Some may set a code for the scan reader, others won't. May be time for a mechanic with the proper test equipment, rather than guessing and throwing parts at it.

 

I had a hole in the vac line feeding my MAP that did this stuff, only 100x worse. Yours could be slightly cracked. For the whole $0.23 it cost to get a new one, you migh just want to replace it.

Also, under load, like climbing a hill in high gear, does the engine seem to fall on its face, then catch up and pull strong, then repeat the cycle? That kind of surging is usually a lazy oxygen sensor. I had one on my truck become lazy enough to make it run like absolute crap, but the PCM never threw a code for it. Yours could be slightly lazy, and not causing major issues yet. A bad o2 sensor can also cause a bad idle.

I wouldn't just go and change the sensor now though. If it is bad, it will become obvious pretty soon.

 

Where is the vac line that feeds the MAp located?

 

Its under the map sensor. Comes right out of the upper intake into the map. Its really short. There are two screws that hold the map onto the braket, I think the are 6 or 7mm maybe smaller.

 

I will take a look at my hanes manual, I have no idea were the MAP is or what it looks like.

Does the Hanes manual have another name for the MAP?