Hi,

This is my wife's daily driver. It has an auto trans, 4 cyl engine, 2 wheel drive, 140K miles.

About two weeks ago I noticed when driving, the car has a slight 'jerking' feel to it. I noticed it again today just a few minutes after leaving my house on the way to the gas station. We haven't drove the car at all today so the transmission wasn't hot and the engine had not reached normal operating temperature yet. I got to the station, filled her up, and headed home. As I was driving I felt the car jerk again. It's just a slight jerk though, nothing crazy. It happens like twice a minute on idle driving and it happens on acceleration and deceleration almost every time.

Other things the car is doing that it didn't used to do. things happened gradually as the miles and age of vehicle went up (not sure if related to above issue):
- acceleration performance has declined.
- after starting and idling engine, the car kinda vibrates a little
- gas mileage has gone down a little.

I appreciate all comments and feedback.
Thank you.
Erik

 

Time for a tune up. Plugs maybe old or coil may be dying.

 

140K you are probably due O2 sensors (lambda's)

The other thing that can do that is if the aircon needs regassing - if you are driving with aircon on switch it off and see if it stops jerking

Aside from that - ditto to Mr grim's comment

 

Hi,

Thanks for the comments.
What is aircon? Where is the switch? and what do you mean regassing?

Thank you
Erik

 

Pretty sure aircon = air conditioning. Regassing = re-charging the air conditioning with Freon as it is low and as a result the air conditioning is kicking in and out (I believe this is what he is saying).

 

Grim_reaper nailed it. Your engine is misfiring most likely because of burnt out plugs, wires and coil pack.
I would also clean the MAF sensor. Replace air filter etc.

Recently I used 1 Gal of Lacquer Thinner (NOT PAINT THINNER!!) in 1/2 tank of gas and ran the Protege for about 100 miles. Of all the fixes in the bottle I have done it had the most dramatic effect. It fixed a P0421 code, starts quicker, accelerates better etc.
The lacquer thinner cleans the whole fuel delivery system, removes deposits in the combustion chamber, pre-cat and cat and it also cleans the O2 sensors. I am planning on doing this to our other vehicles even though they don't have a CEL on.

 

Yes aircon is airconditioning and the aircon compressor kicking in on many cars can cause this fault when the Freon is low. Sorry if my english confused gents :-)

 

There is a recall on the throttle cable and cruise control, this may or may have an impact on driving

 

That recall is only related to V6 engines, equipped with cruise control.