Loss of Ignition
#1
Loss of Ignition
F-150, 1996, 4.9L. Engine quits...cold turkey after traveling ~ 8 miles. Engine cranks but does not start. There is no ignition spark. After a cool down of ~ 10 minutes, engine starts and runs fine for ~ 5 miles then quits. Coil and ignition module have been replaced along with rotor button, plugs and wires. Distributor cap checked, no cracks found.
Have noticed many postings about ignition switches associated mostly with cruise control and dual gas tanks. Truck has dual tanks but no cruise control.
Help will be appreciated. Thanks and have great day!
Have noticed many postings about ignition switches associated mostly with cruise control and dual gas tanks. Truck has dual tanks but no cruise control.
Help will be appreciated. Thanks and have great day!
#2
Join Date: Nov 2006
Location: Memphis, TN 38135, USA, Earth
Posts: 5,495
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1) Buy a light blue Haynes manual (PN 36058) ~$15.
2) Buy a cheap digital multimeter $8-50.
3) Follow the procedure in Ch.5 Sec.5 starting on p.5-5.
If that checks out, get a fuel pressure gauge, connect it to the test port on the fuel rail (inside the intake cage) & run it out the back of the hood to a wiper so you can watch it as you drive & see what happens the next time the truck stalls.
2) Buy a cheap digital multimeter $8-50.
3) Follow the procedure in Ch.5 Sec.5 starting on p.5-5.
If that checks out, get a fuel pressure gauge, connect it to the test port on the fuel rail (inside the intake cage) & run it out the back of the hood to a wiper so you can watch it as you drive & see what happens the next time the truck stalls.
#3
It's got to be the stator
If it is anything but the stator, I would sure miss my guess. Your Ford dealer should be able to test the stator on the vehicle. The stator is in the distributor and requires the distributor to be removed from the vehicle and disassembled for replacement. To test the stator you would have to get your truck in the shop and get it to stall out. Then they would have to hurry and get the stator tested before the truck would normally start. If you took your truck in and it was running, the test wouldn't work. The coil will also act that way, but I see you already replaced that. If the stator tests bad, I would replace the stator in your original distributor rather than going with a rebuilt distributor. I understand the rebuilt distributors are of poor quality. Hope this helps.
#5
Originally Posted by Steve83
IDK what you're talking about, but the only thing inside his distributor is the PIP, and it can be tested effectively ANY time - whether the engine runs or not - using the procedure I referenced above.
#6
Join Date: Nov 2006
Location: Memphis, TN 38135, USA, Earth
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PIP (Profile Ignition Pickup) isn't "my term" - it's Ford's. If you follow my suggestions in post #2, you'll understand the circuit much better. There's nothing that "dies then comes back to life", but when the coil approaches its maximum spec resistance, heat will cause it to go out of limit. Then when it cools off, it'll come back in & the engine will run. So it wasn't ever "dead" (burned out), but it DOES stop working, then start up again. The same thing can happen to the PIP & the ignition module (especially '87-91).