Ford Ranger 2.9l No Spark From Coil

[bigmanpapachuska]

Hey, I have been struggling with this for a while and couldn't find anything that was helping. I have a 1990 Ford Ranger 2.9L, manual transmission. I have replaced the coil and plug wires because I had no spark off of the coil. Still no spark off of the coil. I do have 12V going into the coil when key is in auxiliary. When I use my test light to check the switching signal while cranking, I get a dull glow off of it. I read that on these TFI motors the ECM does not control the spark when starting, and that it only recommends spark advance. Could I be looking at an issue with the TFI or hall sensor? Or is the dull glow the switching signal and I have an issue somewhere else? Thank you for any help I get!

 

[RonD]

Only the TFI controls the spark based on Hall effect sensor inside the distributor
Yes, Computer can change Spark advance(timing) but not whether or not coil sparks

When you disconnect the SPOUT wire, that disconnects Computer completely from TFI

An ignition Coil works by giving it 12volts(+) and a ground(-) to "power it up"
This creates a magnetic field around the Primary coil, "coil" is what it sounds like, just a coil of wire
Inside the primary coil is the Secondary coil
The 12volt magnetic field causes a much higher voltage to build up in the Secondary coil
Lower amps but higher voltage, it not "free power" lol
Say 12,000volts in Secondary

When you cut ground or 12v on the Primary the magnetic field collapses so the 12,000v is released, so Sparks
Since the early days of gas engines with a spark plug the ground(-) was cut to cause spark from the coil, 12v stays on until key is off
And that's still used today even in 2023

Back your vehicle
With key on coil gets 12v, AND should be grounded by TFI module, thats its normal state, coil's (-) is grounded
If you were to put a test light on coils + and - it should flash while cranking engine over, as the TFI module ungrounds the - wire
It will dim because battery voltage drops to under 10v while cranking engine, but should flash/flicker

Cranking speed is abut 200rpm, and there are 3 sparks(V6) for each 1rpm, so that's 600 sparks per minute so about 10 sparks per second, so flicker is more accurate than flash, lol

Google: How to test an ignition coil/module with a test light (distributor ignition)

Watch the video
They didn't mention it but when testing coil + wire you hook test light to Ground or battery negative
When testing coil - you hook test light to 12volt or battery positive, and will get the flicker as seen if its being ungrounded
GM or Ford doesn't matter all ignition coils work the same, even coil packs and COP

If you don't have flicking then TFI module would be the next stop
The Hall effect sensor in distributors rarely fail but thats not never fail

Another thing to check before all this...................see if distributor rotor is turning, there is a gear on the distributor shaft that can come loose, so no spark because distributor shaft is not turning when engine is cranking

 

[SCOTTY]

Only the TFI controls the spark based on Hall effect sensor inside the distributor
Yes, Computer can change Spark advance(timing) but not whether or not coil sparks

When you disconnect the SPOUT wire, that disconnects Computer completely from TFI

An ignition Coil works by giving it 12volts(+) and a ground(-) to "power it up"
This creates a magnetic field around the Primary coil, "coil" is what it sounds like, just a coil of wire
Inside the primary coil is the Secondary coil
The 12volt magnetic field causes a much higher voltage to build up in the Secondary coil
Lower amps but higher voltage, it not "free power" lol
Say 12,000volts in Secondary

When you cut ground or 12v on the Primary the magnetic field collapses so the 12,000v is released, so Sparks
Since the early days of gas engines with a spark plug the ground(-) was cut to cause spark from the coil, 12v stays on until key is off
And that's still used today even in 2023

Back your vehicle
With key on coil gets 12v, AND should be grounded by TFI module, thats its normal state, coil's (-) is grounded
If you were to put a test light on coils + and - it should flash while cranking engine over, as the TFI module ungrounds the - wire
It will dim because battery voltage drops to under 10v while cranking engine, but should flash/flicker

Cranking speed is abut 200rpm, and there are 3 sparks(V6) for each 1rpm, so that's 600 sparks per minute so about 10 sparks per second, so flicker is more accurate than flash, lol

Google: How to test an ignition coil/module with a test light (distributor ignition)

Watch the video
They didn't mention it but when testing coil + wire you hook test light to Ground or battery negative
When testing coil - you hook test light to 12volt or battery positive, and will get the flicker as seen if its being ungrounded
GM or Ford doesn't matter all ignition coils work the same, even coil packs and COP

If you don't have flicking then TFI module would be the next stop
The Hall effect sensor in distributors rarely fail but thats not never fail

Another thing to check before all this...................see if distributor rotor is turning, there is a gear on the distributor shaft that can come loose, so no spark because distributor shaft is not turning when engine is cranking

Any signs or symptoms on the distributor shaft gear coming loose ? I was driving along just fine today & the truck just died & no spark @ the coil. I'm hoping it's just the coil & haven't checked anything else yet.
Thank you !

 

[alwaysFlOoReD]

Pop the distributor cap off. Crank the engine (get a helper if you need to) and watch rotor, it should turn. No turn means gear is stripped or off.

 

[SCOTTY]

Pop the distributor cap off. Crank the engine (get a helper if you need to) and watch rotor, it should turn. No turn means gear is stripped or off.

Aware of that & thanks. Just wondering if there are any symptoms of it while it's still running before the occurrence.

 

[SCOTTY]

Another question please:
Is it common or rare for the gear on the distributor shaft to become loose or stripped ?
I can't get to my truck right now.
Thanks

 

[SCOTTY]

Well the bad weather aint helping any. So far I checked coil & have 12v w/key on. Lifted d-cap high enough to confirm rotation.
Will check condition of cap & rotor @ another time. Need to get a test light to confirm flashing.
Out of curiosity in case I need one, which brand is the best TFI module to get ?
Thanks !

 

[rusty ol ranger]

Well the bad weather aint helping any. So far I checked coil & have 12v w/key on. Lifted d-cap high enough to confirm rotation.
Will check condition of cap & rotor @ another time. Need to get a test light to confirm flashing.
Out of curiosity in case I need one, which brand is the best TFI module to get.
Thanks !

The best TFI's are motorcrafts.

Make sure to get the grey one.

 

[SCOTTY]

The best TFI's are motorcrafts.

Make sure to get the grey one.

Thank you for that ! I made the mistake of assuming the Ford/Motorcraft ones weren't made anymore.

Any recommendations for thermal paste ?

 

[rusty ol ranger]

Thank you for that ! I made the mistake of assuming the Ford/Motorcraft ones weren't made anymore.

Any recommendations for thermal paste ?

I think it usually comes with some in the box.

Usually advanced auto and a few places online have motorcraft tfi's

 

[SCOTTY]

I think it usually comes with some in the box.

Usually advanced auto and a few places online have motorcraft tfi's

I asked & I was told no compound comes with the Motorcraft TFI.
I'll be ordering some Artic Silver 5 along with it + the TFI tool.

Thanks for replying rusty !

 

[rusty ol ranger]

I asked & I was told no compound comes with the Motorcraft TFI.
I'll be ordering some Artic Silver 5 along with it + the TFI tool.

Thanks for replying rusty !

No problem!

 

[SCOTTY]

I've been seeing quite a bit of talk on counterfeit Motorcraft TFIs on the web.
Can anybody suggest a good place to get 1 ? I'd hate to get stuck with a bad TFI.
Thank you !

 

[rusty ol ranger]

I've been seeing quite a bit of talk on counterfeit Motorcraft TFIs on the web.
Can anybody suggest a good place to get 1 ? I'd hate to get stuck with a bad TFI.
Thank you !

Advance used to carry them. But i cant get their damn site to work.

As long as you buy from somewhere reputable (as in, not amazon or ebay) you should be fine

 

[SCOTTY]

Advance used to carry them. But i cant get their damn site to work.

As long as you buy from somewhere reputable (as in, not amazon or ebay) you should be fine

Thanks rusty ! Btw, Advances site can be real screwy, especially the "search" with me