Expert: Roland Finston - 1/29/2012

Question
Hello Expertise ,
I have a chrysler sebring 98 2.5 V6 engine which i spent money alot lately to fix the problem and no one could actually fix it ! my engine starts shaking and looses a power on acceleration tow months ago right after installing a new timing belt and a water pump, i took it to the same mechanic and he said there is a miss fire and an oil leak into the spark plugs , so i installed a new wires,plugs,distributor and changed the O rings seal on each plug.. and nothing fixed , so i took it to another mech and he said a Low pressure on cylinder No.2 so i did a head job and changed one Vavle and also did not Fix the shaking at all,so after the head job mech said lets change the fuel sensor (nozzle) and we did the engine runs great.. after one day the shaking is back and it's exactly the same ..
pls any ideas

Answer
Hi Aboud,
Did the last mechanic identify whether the shaking that started again involve just one cylinder (#2) or is the miss on all cylinders? If you don't know, then I would go back and ask him to read out the fault codes from the engine controller and get the specific fault code number(s). All cylinders would be 0300, while cylinder #2 would be 0302 code.  Then we can consider exactly where to look or where to ask him to repeat the job.
Because it worked for a day suggests that he may not have done the job correctly as it didn't 'hold'. It may just be the wire that connects the #2 injector to the engine control module is flaky and not the injector itself. That wire is tan in color and is connected to pin 17 at the ecm. So have him check that wire for continuity while shaking it. Also check that the dark green/orange wire at the injector plug is solidly connected to the other injectors' dark green/orange wires on that same side of the engine.
If you don't want to do that, then take the car to a nationwide autoparts store such as Autozone and ask them to do a free code readout to get the specific fault code numbers.
Does is shake ONLY when you are accelerating? and then runs smoothly at a steady speed?
Roland
PS Sorry for the delay in answering but I just found your question in the 'pool' to which Kevin had referred it. If you would be so kind as to 'rate' my answer and give a 'yes' where you see the question about a 'nomination for volunteer of the month', I would appreciate that.