1989 Ford Ranger Repair Question
1989 Ford Ranger loses spark after 15mins running
1989 Ford Ranger 6 cyl Two Wheel Drive 98778 miles
loses spark after running for about 15min. but starts right away after that it lasts about five and so on until it quits completely i have replaced dist ,coil,module computer and relay fuel pressure never drops have check all gounds and power replaced harnes to dist cleaned injectors checked ign. switch both dist wires neg dose pulsate except when it quits completely. it all started after being at body shop for 5 mon. did drain fuel . please help
Answer
what the car was in the body shop for? do you have any codes or no codes?, included pending codes?
no codes it was in body shop for reg paint job have checked for burn wires ground straps and nothing.
crank sensor will make the car to die. Try tapping on it once the car gets warmed up.
there is no code,
disconnect any sensor , start the car and see if there is engine light. make also sure the computer ground is clean.
diconnected tps and got a code for that , 2.9 has no cranksensor . iv got a wire going from eec power relay to o2 sensor would 02 sensor once heated do this problem? bk/ltgrn wire
I do not think it the heated oxygen sensor.
according to the diagram , the BL LT gr wire could be the cause.but you could test it and get it out of the way.
I'm sending a diagram so we can work on it together.
the problems is electrical,chassis ground after the car have been inactive could cause the problem.
you said tested all ground, included chassis?because rust is the enemy of chassis ground.
look at the diagram, the ignition coil is grounded to chassis.

if you can't see I'm sending the same diagram by email to you.
Measure the resistance between the ICM terminals as shown below:
GND-PIP IN: should be greater than 60 ohms.
PIP PWR-PIP IN: should be less than 2,000 ohms.
PIP PWR-TFI PWR: should be less than 200 ohms.
GND-IGN GND: should be less than 2 ohms.
PIP IN-PIP: should be less than 200 ohms

module checked out ok i ground coil direct from bat and still the same checked all ground there was one with some rust but still the same thing.
let's turn the page.
Coolant temperature sensor need to be checked.
it is well known to give wrong information to the computer, also because of "no code"
keep me updated.