You can try the MAP whack but idling okay doesn't guarantee the fuel injectors are good. If their max flow is impeded they can still squirt enough at idle yet under-flow at WOT.

 

o2 sensor??? does it go away at WOT?

 

It could be alot of things I'm leaning towards fuel.
I have an 02 with 170k miles I just got. The car ran decent than got worse.
I sent my injectors out to get cleaned and tested. They were poor I also replaced the fuel pump,sock and fuel filter in the tank. I also changed out the fuel pressure
regulator. The car is like new again if you can check your fuel pressure.
Do you have a CEL?

 

Did your car exhibit the exact same symptoms as mine (jerking/lurching)? Nope, no CEL.

 

Ok... about a month ago, my car was behaving like how I'd described in my first post. I didn't know what the problem was so I whacked the MAP sensor hard a few times, since I had nothing to lose. The car ran good for a couple of weeks and the same lurches came back. I assumed it was just coincidence that the problems went away with the initial whack.

This morning, I whacked the MAP again and have been VTEC'ing a few times today with no issues. Perhaps the MAP is on its way out and I'm just squeezing the little life it's got left with the whacks? What is the reasoning behind the whack anyway? Design flaw?

 

I don't know how MAP sensors are constructed but if a whack fixes it then it sounds like a contacting potentiometer (as is used in many gas pedal sensor designs).

If so, there is a metal contact wiping across a resistive element (film, wire-wound, or whatever). The element can wear, usually at the ends (idle & WOT) where the contact spends more time, making a bad spot. Often contact tracking is so precise that a slight disturbance or position adjustment (whack) can restore function, at least temporarily. But a highly worn film or contact is on its last legs.

Why do sensors in one car die and not the same sensor in another same-model-car? Aside from tolerance differences between sensors (and manufacturing defects), there are differences in -- how cars are driven, how rough the roads are, how hot or cold (or temp cycling), and how well balanced each engine is (vibration really kills contacting pots).

 

Thanks for the explanation. Yea so it seems like the MAP is the culprit. The car seems to run smoothly throughout the throttle input, for now. As for preventive good measure, I guess I should get the fuel injection cleaned anyway at this mileage too, as suggested.

 

does anyone know if you can clean the hole in the map sensor? or if the construction of it allows the hole to get clogged?

 

Where would I send the fuel injectors to get them cleaned? Can I have this done at the dealer while I wait for an oil change? Is this something Billman250 can do on the spot with basic tools?

 

I asked my tech about fuel injector cleaning and he mentioned the Motorvac injector and carbon cleaning machine that uses high pressure hoses and chemicals. He said it does not require fuel injector removal from the car.

Is this the type of injector cleaning that you guys mentioned up above?

Just wanted to make sure.