car jerks when I stop at the stop light. If I turn off the a/c it seems to go away. it doesnt jerk while i accelerate just while at a complete stop. seems like a miss fire. but i really dont know! the other day i drove through mad rain and it seems like water got in the the engine and splashed up onto the hood. once i got into Oralndo and hit a red light it started to jerk. funny cuz it never did that b4. please anyone can help thanks

 

What you're explaining is a rough idle, not a jerk. A jerk would be your car jerking forward or backwards at idle. If your car was jerking, I would say a bad pressure plate but your rough idle seems like a broken vacuum line or water in one of your electrical connections.

Start by unhooking sensor and main electrical connections and blowing them out with compressed air. Once done, start it up and hopefully it runs right.

 

if you say water got in the engine then do an oil change then see ,if not check the plugs wire, spark plug or check the rotor in the dizzy

 

well i guess its not "jerking" its not rocking back and forth but its shaking a bit...but not a constant shake. when i stop at stop light it will shake once then stop 20sec or so later shake again 2x then stop...shakes more when i turn A/C on....well i thought it was the cheapo Duralast spark wires...so i return those and got Bosch spark wires. but that didnt make a difference. i did a tune up like a month ago on the car. i will check the vacuum line and water in all the elec plugs and rotor. thanks for your help guys! any other suggestions that would be great!

 

isit shaking like the idle is low?

 

Sounds like the ilde air valve... if it shakes real bad with the ac on... cause its not upping the idle for the extra load..

 

If water got spashed on a warm distributor, condensation inside the cap will cause spark to jump to the wrong plug and cause rough idling/jerking/misfiring. A/C on, adds drag to the engine and makes the problem worse.-Bob

 

geeze today i brought it over to my friends shop and he cant diagnose it!! ahh so annoying! he checked the sparks, wires, distributor, checked some sensors on the throttle body and everything seems fine...then it started to rain real bad so i left but like i said...its not a constant jerk it jerks then stops for 10-20 secs then jerks 2-4 times in a row then stops then 30secs later jerks again...something like that...and i notice it jerks the most while in drive and reverse and when the A/c is on but it does jerk a little w/out A/c. When it does jerk, i watch the RPM and it doesn't move much. stays around 6-700. the car never shuts off. transmission problem maybe?

 

Doe it jerk only when the engine is running?
Running in gear?
Coasting? -Bob

 

it does it when engine is on but not coasting. when its at a complete stop in gear. when its in park it doesnt do it ( i believe).