2.9 intermittent spark from coil!!?

[Chuckc]

1988 bronco ii curse.. replaced fuel system. Most sensors and whole ignition system including computer.. went threw wiring harness fixed sketchy connections. Runs rough backfiring. Has intermittent spark from coil can watch timing light or in line spark tester blink steady and stop at same time engine misses (intermittent coil signal) please help!!

 

[rusty ol ranger]

Sounds like the ignition module or pickup coil.

Pull codes and lets see what ya get there.

 

[Chuckc]

New ignition coil and new distributor

 

[RonD]

Wouldn't matter what is "new"
New now means "never tested so YOU TEST IT and we will replace it under warranty"

So because its "new" just means if there is a problem get another one

The TFI spark system is self contained, unhook the SPOUT wire jumper so there is no connection to computer
Test spark again with timing light
If its still misfiring then its down to TFI module and distributor, for sure

If TFI is not grounding the Coil, then ungrounding it to spark in a regular rhythm, its usually the distributor Hall Effect sensor or the rotor/cap setup
Distributor is new so bushings should be OK, but not always, you can get a wobble so the coil spark can't jump the gap at rotor/cap so you get that missing spark/timing pulse
The hall effect sensors is pretty simple and not likely to cause an issue, but its "new" so suspect

 

[Locotomb]

New cap and rotor? Resistance test plug wires?

 

[Locotomb]

Oh yeah and keep your coil/distrib wire away from all other wires as much as possible.

 

[PetroleumJunkie412]

From personal experience, unless your TFI module and hall effect sensor both say "Motorcraft," neither will work.

 

[Chuckc]

Thanks guys nice to have some reassurance before ordering and replacing new parts.. I have new tfi module and Hall effect sensor on the way.. their not motor craft might debating sending back and getting better quality parts

 

[Chuckc]

Also in cleaning up some of my wiring connections I cut out idm resistor.. is this necessary?

 

[Chuckc]

New cap and rotor? Resistance test plug wires?

Sounds like the ignition module or pickup coil.

Pull codes and lets see what ya get there.

 

[Chuckc]

Only code 67 and I’ve replaced nutral safety switch code still their

 

[Chuckc]

Yes a

New cap and rotor? Resistance test plug wires?

yes all new

 

[rusty ol ranger]

Only code 67 and I’ve replaced nutral safety switch code still their

Code 67 comes up when you do a KOEO test with the transmission in gear (manual). Disregard it.

 

[Chuckc]

Wouldn't matter what is "new"
New now means "never tested so YOU TEST IT and we will replace it under warranty"

So because its "new" just means if there is a problem get another one

The TFI spark system is self contained, unhook the SPOUT wire jumper so there is no connection to computer
Test spark again with timing light
If its still misfiring then its down to TFI module and distributor, for sure

If TFI is not grounding the Coil, then ungrounding it to spark in a regular rhythm, its usually the distributor Hall Effect sensor or the rotor/cap setup
Distributor is new so bushings should be OK, but not always, you can get a wobble so the coil spark can't jump the gap at rotor/cap so you get that missing spark/timing pulse
The hall effect sensors is pretty simple and not likely to cause an issue, but its "new" so suspect

Well replaced tfi and Hall effect sensor and same thing actually running a bit worse now..

 

[PetroleumJunkie412]

Well replaced tfi and Hall effect sensor and same thing actually running a bit worse now..

How does it run with the spout connector disconnected?

What is.your base timing set to?