1987 Bronco 5 liter,

[pastorbud]

I posted on this previously, thinking I had a vacuum or EGR problem, killing the engine after it warmed up. I bought a more reliable spark tester, and what happens is I have no spark at the plugs, or out of the coil, after the engine warms up. Let it cool off af few hours, it fires right up.

Then, after 10-20 minutes, it dies and won't re-start, even though I have power at the coil, and a new coil, ignition wire, ECM module (the one on the side of the distributor), distributor cap, rotor, plugs and plug wires.

What's left??

 

[Yardape]

Maybe a faulty new coil perhaps?

 

[Shadow_D]

I have to agree with Yardape with this one. If you have power going to the coil but it won't spark then that could be your trouble.

Ignition Coil Test:

The Ignition coil must be diagnosed separately from the rest of the ignition system.

1) Primary resistance is measured between the two primary (low voltage) coil terminals, with the coil connector disconnected and ignition switch off. Primary resistance should be 0.3-1.0 ohms.

2) On DuraSpark ignitions, the secondary resistance is measured between the BATT and the high voltage (secondary) terminals of the ignition coil with the ignition OFF, and the wiring from the coil disconnected. Secondary resistance must be 8,000-11,500 ohms.

3) If resistance tests are ok, but the coil is still suspected, test the coil on a coil tester by following the test equipment manufacturer's instructions for a standard coil. If reading differs from the original test, check for a defective wiring harness.

 

[Seabronc]

If you have a Duraspark II system, that is the symptom of a bad pickup coil in the distributor. When they go bad the engine will start when cold and then after it heats up it is like someone turned the ignition key off. Also when that happens you get no spark because there is no pulse to trigger the ignition module. Trouble shooting procedure attached. This procedure will give you some instructions on building a simple test tool and how to determine if the problem is the pickup, coil, or ignition module.

Good luck,

>-

 

[pastorbud]

If you have a Duraspark II system, that is the symptom of a bad pickup coil in the distributor. When they go bad the engine will start when cold and then after it heats up it is like someone turned the ignition key off. Also when that happens you get no spark because there is no pulse to trigger the ignition module. Trouble shooting procedure attached. This procedure will give you some instructions on building a simple test tool and how to determine if the problem is the pickup, coil, or ignition module.
Good luck,

>-

Seabronc-- Not sure I have the Duraspark II. It's a 1987 5.0 liter, w/ EFI. Ignition Control Module is on the side of the distributor. I don't remember seeing an armature inside the distributor like the one in the diagram, but will pull off the cap and check. I do remember seeing components (something in curved white ceramic insulator on the perimeter of the distributor) in there when I replaced the ICM, and thinking, "Gee, maybe I should just replace those while I'm at it." Hindsight.

This whole thing makes me miss the points and condenser days! I think the space shuttle is either to diagnose than today's ignitiion systems.

 

[Seabronc]

Seabronc-- Not sure I have the Duraspark II. It's a 1987 5.0 liter, w/ EFI. Ignition Control Module is on the side of the distributor. I don't remember seeing an armature inside the distributor like the one in the diagram, but will pull off the cap and check. I do remember seeing components (something in curved white ceramic insulator on the perimeter of the distributor) in there when I replaced the ICM, and thinking, "Gee, maybe I should just replace those while I'm at it." Hindsight.
This whole thing makes me miss the points and condenser days! I think the space shuttle is either to diagnose than today's ignitiion systems.

Sorry, I missed the fact that you had an EFI. You have an EEC system. However, the symptom is still similar with a bad TFI module, ( the thing that sticks out the side of the distributor). Most of that proceedure is no good for EEC and the pickup is different. Unfortunately that proceedure for your year truck is in a shop manual that I don't have.

 

[miesk5]

yo, try a Self Test with eng off - key on for trouble codes; when cold and when hot after it shuts down;

http://fordfuelinjection.com/?p=13

 

[pastorbud]

yo, try a Self Test with eng off - key on for trouble codes; when cold and when hot after it shuts down;http://fordfuelinjection.com/?p=13

Like with a code scanner? Don't have one, but s'pose I could rent or buy one.

BTW, new PIP Sensor (more commonly called Pickup Coil) got installed in the distributor tonight. Hope to install the distributor and test tomorrow.

 

[miesk5]

Bud,

No scanner needed for the DIY Self Test; read Ryan's info there; ez to do GL!

post any codes found here or look them up in Ryan's Link

 

[pastorbud]

Bud,No scanner needed for the DIY Self Test; read Ryan's info there; ez to do GL!

post any codes found here or look them up in Ryan's Link

Oh, got it. Good stuff to know.

 

[pastorbud]

Bud,No scanner needed for the DIY Self Test; read Ryan's info there; ez to do GL!

post any codes found here or look them up in Ryan's Link

Installing new PIP Sensor (Pick-up coil) in distributor did not fix. Will perform tests per link. This is SO frustrating. <_<

 

[pastorbud]

yo, try a Self Test with eng off - key on for trouble codes; when cold and when hot after it shuts down;http://fordfuelinjection.com/?p=13

Had a buddy come over to help me with this, and we happened to remove the cover to the connector in the firewall going into the computer on the driver's side.

Found two broken wires hidden inside the cover. Patched. Fixed. Sheesh.