Got a misfire or a jerk when cruising at highway speed and accelerating. Cant track it down. Replaced the dpfe sensor because broke the spot the tube goes on, had a code for a cat plugged so gutted this one for the time being till the new one arrives, and had new plugs put in less than a year ago. Throws no codes (except the cat code) and dosent do it all the time just here and there. Starting to bother me. Seems to be a lean misfire but not 100% sure. Any assistance would help.
Ajpep
Most common cause of misfire on a Zetec (DOHC) is a failed/failing ignition coil. This can occur without any CEL/DTCs. Remove the coil from the vehicle (4 bolts) and carefully examing it for cracks in the insulation - especially on the bottom and around the towers. Also carefully inspect the vehicle's harness/connector which it connects to the coil.
Good luck
Paul
Good luck
Paul
The wires can definitely do it too.
ignition miss on a zetec may be at idle but commonly under light to medium load. At full throttle they may not miss at all, odd as compared to most engines.
Not looking for big cracks there, commonly they are very small and easily overlooked. Moisture then creeps in and the coil shorts windings under load.
Zetecs are well known for rear of engine PCV hose leaks at idle, might wanna check that too.
ignition miss on a zetec may be at idle but commonly under light to medium load. At full throttle they may not miss at all, odd as compared to most engines.
Not looking for big cracks there, commonly they are very small and easily overlooked. Moisture then creeps in and the coil shorts windings under load.
Zetecs are well known for rear of engine PCV hose leaks at idle, might wanna check that too.
New event. Havent got to ignition coil or wires but was driving to work this morning and was missing really bad. After a while the car started to die and drop rom without my control. All of a sudden a loud bang from the back of the car. Blew a hole in the muffler. Ran pretty good for about 10 minutes after that with no misfires, then they started again. Starting to maybe think its a plugged muffler? Possibly too much exhaust backpressure? Or what are your thoughts?
Ignition is fine. Put new ignition coil on still had the problem. Put a new timing belt on tonight and noticed the exhaust cam was off a tooth, times it all back up, put the new cat in and still having troubles. Seems now that the car isnt misfireing as much but will run awesome up untill it warms up. Once to operating temp the car just dies. Maybe misfires once before dying. Going to look into collant temp sensor tomorrow and maybe ecm.
The ignition is NOT fine if the wires are old. They can misfire like you are getting all day long. Zetec wires commonly pull apart inside while changing the plugs, the conductor is carbon dust impregnated string.
The misfire will now kill your new cat and what it does, it doesn't take much to do it either. What caused your previous explosion in pipe, unburned raw fuel stacking up in exhaust, death to a new cat.
Waiting for the inevitable changing of the PCM for no reason, what they all do.
If original fuel pump all could easily be that.
The misfire will now kill your new cat and what it does, it doesn't take much to do it either. What caused your previous explosion in pipe, unburned raw fuel stacking up in exhaust, death to a new cat.
Waiting for the inevitable changing of the PCM for no reason, what they all do.
If original fuel pump all could easily be that.
Need like 40 psi. The pump driver module sends the speed all over the place.
You can get pressure and if fuel filter stopped up then it doesn't get to engine. As well there was a recall on earlier cars than that one over pumps but not really a Ford issue, more like the ethanol suppliers letting lots of crud get into the tanks. Still a problem today and some of that crap literally fills up the entire pump module to make for very wonky running. I've pulled them apart to clean and found a whole pair of handsful of white snotty crap (or solid red sedimental mud, take your pick) inside the module before and all of it comes off with water, fuel or solvents will not touch it. Ethanol water based trash.
By the OP language the pump works at idle but shows straining at more load which is either fuel supply or ignition and if the ignition has been addressed properly then nothing left to do except look elsewhere.
You can get pressure and if fuel filter stopped up then it doesn't get to engine. As well there was a recall on earlier cars than that one over pumps but not really a Ford issue, more like the ethanol suppliers letting lots of crud get into the tanks. Still a problem today and some of that crap literally fills up the entire pump module to make for very wonky running. I've pulled them apart to clean and found a whole pair of handsful of white snotty crap (or solid red sedimental mud, take your pick) inside the module before and all of it comes off with water, fuel or solvents will not touch it. Ethanol water based trash.
By the OP language the pump works at idle but shows straining at more load which is either fuel supply or ignition and if the ignition has been addressed properly then nothing left to do except look elsewhere.
Fuel filter first, if it helps, tells you to drop tank.
Drain the filter, commonly they are half full of water from the ethanol. The clear/black stuff. The filter acts like a semi-water trap but the water clogs the filter pores solid so nothing can get through.
Filter commonly located just in front of tank on pass side.
Drain the filter, commonly they are half full of water from the ethanol. The clear/black stuff. The filter acts like a semi-water trap but the water clogs the filter pores solid so nothing can get through.
Filter commonly located just in front of tank on pass side.
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