Contour Enthusiasts Group Archives Forums General Troubleshooting Miss under acceleration!

So I had the Bosch P4s, they were okay but I did notice some hesitating with them. I went to replace them and all i could get from two autpoparts places were the MotorCraft FMs and now the car runs barely.
Are the FMs really that bad or did I somehow create another problem?

Nevermind, im a F****ng Dumb*zz. I reversed the wires for 1 & 3. She runs on 4 but seems happier with 6.

my car is doing the same thing. one thing that i hear is after the car starts up a few minutes,later you hear a very very lite tick coming from the back by the firewall its one of the plug wires it is faulty but time runs out before i get a chance to find which one. the wires look fine but after they get hot things change. if you have a bad cyl not firing right when you read the plugs you should be able to notice the difference. i will post my findings later today if i find them because driving the tour is killing MY NEED FOR SPEED so i guess i will drive the stang today

I have also had this problem with my car for a long time now. I have replaced the wires and the coil pack. I determined that it is not them. I recieved a miss fire on cylinder #3 code after a long time, so I thought maybe a bad injector. I replaced the injector on cylinder three and cleaned the intake manifolds. The problem still exsists but seemed slightly better but I assume that only comes from cleaning the manifolds. Someone told me that the emissions plunger on the back of the upper intake manifold near the EGR valve gets clogged by carbon build up and causes similar problems, but I have not had a chance to look into it. If anyone figures out there problem let me know. Thanks.

well what i found was the plug wires dont hold up too well, i found out because i started up the car in the dark about 11pm and the light show from the wires was crazyyy. the spark was low thru the wires to the back side of the motor. when the wires came close to the intake manfold the spark got greater. the wires are motorsport a set, the front wires did not spark. i tried to tape it with my digital camera but no luck. to me this will explain the missing bc they only show up when the car is warmed up.

TourDeForce: The numbers are not on the Sorensen replacement coil pack, but I verified the wire routing with my shop manual CD. Besides, the miss is ONLY when accelerating, and only then under certain conditions (see my previous posts in this thread). I just got back from a 700 mile round trip to Fort Wayne, IN. The problem has become more noticeable, but still only under the same conditions as I previously described.

Can the MAF be going out without failing completely? I have cleaned it, but if there is a different problem, I will gladly replace it. Is there a diagnostic for the MAF that a person can do with a digital VOM or standard scan tool? I don't want to spend about $100 bucks on a new unit if this isn't the problem.

Glad to help and glad to know it worked for ya.

One heads up though - don't be surprised if it comes back.

I'll know what to look for next time if it does return. The car is running extremely well now (knock wood), I couldn't be happier!... Well, if it made 150 more HP I'd be happier...