97 t/bird LX 4.6 Auto. Has new fuel components but no spark and wont start. What is the diagnostic procedure for no spark
Asked by bluebell2 Sep 03, 2014 at 12:01 AM about the 1997 Ford Thunderbird LX RWD
Question type: Maintenance & Repair
ran rough for a 5 - 10 minutes then stalled. Presumed plugged fuel filter. Changed the
filter to no effect, Assumed pump failure, changed in tank fuel pump, no difference still
no start condition. Read something online looking for a fix - crank position sensor
failure causing no fuel and no spark sounded logical, replaced crank position sensor,
still no result and no run condition prevails. There is no spark on any plug. I do have
good fuel pressure at the fuel rail, the engine is mechanically sound with only 42,000
miles on the clock. Need a diagnostic flow chart from this point forward, can anyone
help?
6 Answers
Does this have one of those long coil wires, and the E-core coil up front, passenger side? Check for spark arcing to the body. I had one like that and we re made the wire ends, then replaced the wire set later.
so, does it have coil on plug or a set of wires and a coil pack or what. That crank sensor you put in would take the place of a set of points in this design. and if you have a coil pack, you would have an EDIS module. After you i.d. the system, the public library mayy have an automotive database you can get your testing info from. Your OBDII service code(s) can simplify this some. you can get a tester at the parts store and return it perhaps when finished. you will need a DVOM and a 12v test light perhaps.
You know you do not have any spark so just do a rutine troubleshoot. Is there voltage to the coil(s). If fo is the spark getting to the plugs. Are plug wires all good and not being grounded anywhere. Shouldnt be too hard. Although I am not familiar with your particular car they are all about the same.
so it stalled after rough run. you guessed filter and pump, then learned of crank sensor from internet. replaced crank sensor Theres no spark on any plug you say. makes me think you have a set of plug wires on this design. You really need codes next, and i.d. the ignition system for us. the code can lead to a module, or cam sensor or who knows. the low miles makes me remember when they were new. we did a few cam sensors on no starts and they bucked when trying to start. this was firing on the wrong bank. we could really use the code info as you can tell.
this is the 4.6L romeo. they had plug wires at first. lots of wire failure noticed when they were new. If it has an E-core coil, you could use a 12v test light at the coil connections one side steady-on the other flashes when crank.
I have a 97 4.6L thunderbird that has no spark. I almost pulled out my hair researching the problem. I changed out the camshaft sensor with no luck.I have a truck with the same PMC so I switched them out with no luck. Finally in the dark with a flashlight I followed each wire coming from the coil and one going to the crankshaft sensor. I was going to replace the sensor but you have to remove the air compressor so I loosened the sensor up moved it some then tigthen it back up and low and behold it cranked right up. I hope this helps someone.
