I would like to bring up "bucking" in general. Through my experience, my car with manual tranny (at any speed) will hesitate/pause for split seconds, and immediately jerk/lunge or buck as if to catch up from the hesitation. Also, no problems with RPM limitations (like similar post before mention <4k>).

Again, through my experience- It has still happened after the following parts have been replaced:

Plugs
Wires
Coilpack
Fuel Filter
Air Filter

How can we kill the bull and put an end to the bucking? Is it a direct cause from anything? like maybe:

MAP sensor
Coolant Temp Sensor
Clogged ERG tube
Faulty ECU
Age old injectors

Sometimes the buck can be pretty serious, but other times not so rough. Can also seem to go away for weeks, but then return. What is exactly happening when our cars do this, and is there a final solution for 2gnt owners who have this problem?

Originally posted by .bs0d
MAP sensor

Pull it and make sure it's clear?

Originally posted by .bs0d
Coolant Temp Sensor

Definite possibility if you've not changed it yet.

Originally posted by .bs0d
Clogged ERG tube

Disable the solenoid and see what happens?

Originally posted by .bs0d
Faulty ECU

Try swapping with a friend?

Originally posted by .bs0d
Age old injectors

Possible. I would look into this just before the ECU imo.

Does this only happen when you slam down on the gas(floor it)? My Jeep TB doesn't like to be instantly floored at lower RPMs. It'll do exactly what you're saying when you floor the 60mm - buck around. If you roll onto the throttle it works fine though. And I'm not talking like a 10 second roll on or anything - I'm talking about more like a 1/2 to 1 second roll on. As long as its not an instant "full throttle". At least thats what my experience has been with the 60mm Jeep. It only does it to me when its already at lower RPMs like around 1000-2500. Anything above that(at least for me) and you can instantly floor it and the motor picks up just fine. And remember, I've got cams and a bunch of other shit goin on so the flooring-stall-range may be a little different for you.


95 Eclipse RS : 5 speed
15.7 @ 87.9mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Bucking can be a result of an ignition problem.

Other sensors to consider are:

Camshaft Position sensor.
Crank Angle Sensor.

When my camshaft sensor was on its way out (150k), the bucking and studdering was pretty bad, then other days it really wouldn't happen. It finally took a shit and left me stranded in the snow.

Got it running thanks to a a dodge dealership in the area open till 11pm mon-fri!

Hey man, check your wiring too.
I posted something like this also about 2 months ago concerning about my g/f's car.
I changed fuel injectors, spark plugs, wires, coil, ECU, and checked every sensor!

and at the end, I found out, the air filter (CAI) is rubbing against the ECU wiring. and distroyed the wrapping of the wires and got contact with the yellow wire (grounded/short circuit). and that yellow wire I checked is used to control the 3rd injector. as soon as I fixed it, NO MORE bucking!
So.. that's that! just let you konw, it might be something really small but stupid!

Hope it helps.
Gil

I jsut fixed my slight bucking prob. I had a small fuel leak.

Where was the fuel leak comming from?

Originally posted by .bs0d
Where was the fuel leak comming from?

Well I modified a 95 fuel rail cuz its a bigger diameter (probably made no difference),but I welded both ends and tapped them to run -AN fittings on each end. Well the return side was leakin, pin hole in the weld.

But I have had a fuel leak where the hardline and softline meet.

my problem with my car when i had the bucking / misfiring problems was the crankshaft and camshaft sensors.

Removal of the EGR cured mine. I replaced everything that you mentioned also to no avail.

Hope we are narrowing this down for you. The buck sucks!!!

yes, the buck does suck!

Finding an ERG-blockoff kit wouldnt hurt... thanks

I had misfire problems for the longest time. Replaced practically everything. Turned out to be crank position sensor.

I havent replaced that sensor, is it ok to get one from O'Reilleys or Autozone? Or is it recommended to go with Satan?