The FLIPPIN Coil !

[a31ford]

Been Chasin (Hi everyone !) Been chasin this dern problem for over a year now, "decides to run rough, beltches, farts, and in general, bad gas mileage"...

So the other night, I got really, I mean REALLY pissed at my Ranger, grabbed my oscilloscope of my electronics bench, my 500 watt inverter, and fired up the oscilloscope from the passengers footwell, so I could watch the PIP line while driving around at dusk.

Notice this stupid "back curve" every now and then in the pulse train comming off the PIP line from the engine computer... Funny, the back curve is when the engine misses or beltches (not all the time).

I stop, open the hood, and "POOF" the coil looks more like the glow from a plasma cutter than a coil, Scotty, Warp 6 please !

Honest to god, the coil looks like a plasma generator, and every now and then ZAP !, a nice big blue arc, and the engine misses.......

36 bucks later, and a nice pretty blue "Standard" ignition coil , problem gone....

in ALL my 38 years of engines.... NEVER have I SEEN THIS ONE.

For those that have rough running 2.9's check the coil.........................

Greg

 

[Road Angels]

when ever I get a miss I always find a dark place pop the hood and look for arcing, I have fix many a car that had a transient spark some where that others couldn't find

 

[RonD]

Make sure coil only has 7volts while engine is running or you will have the same thing happen over time.

Coils usually have less than 1 ohm resistance, 0 ohms is a dead short and you know what a 12volt short does, melts wire and insulation, lol.

Coils are usually give 12v when engine is cranking for hotter spark, but then when running a ballast resistor takes over to lower the voltage to approx. 7volts, this reduces the heat in the coil since it only has a 1 ohm resistance

 

[ab_slack]

I had a crack in the insulator on the underside of the output terminal from the coil. Nothing was ever visible. The only symptom I was really aware of was an occasional miss and bad noise when listening to the radio which came and went intermittently but particularly after it rained and for some odd reason...when I turned left of all things.

I had looked in the dark like Ron suggests and often had success but saw nothing.

Eventually replaced wires, cap, rotor and coil. It is only when I got the coil off I saw the crack and that was the cause.

Congrats on finding that bugger that plagued you so long.

 

[Mark_88]

Good to know...I've been a bit reluctant to switch to FI because there are so many little parts that can cause different symptoms and the thought of chasing them around when I really need to fix something has me concerned...not to mention the cost of replacing some of those parts (sensors or otherwise).

Has anyone made a reference chart that gives parts and symptoms they would cause? I've read enough over the years that I have a fairly general idea of what could go and what happens when it does, but until I actually troubleshoot a problem on a FI system it's all hypothetical...

 

[Andy D]

Heh Heh . Carb guy up to '96 when I bought my first car with EFI. It is essentially the same set up as the Rat. EFI is waay better than any carb. And 90 % of any troubles are electrical.usually a loose fuse. The scary little black boxes in the wiring are scary because you can only replace them and hope. Trouble with that mindset is that the stuff is pretty robust, if you keep it fed with good voltage. I'm Grudgingly admitting this.

My bad coil was on a 360 V8 in a Wagoneer with a 2150 carb. I chased that miss through every part of the carb. It would load up the cat with raw fuel until it melted, split 2 mufflers with back fires. Started fine, ran rich, but ran. The fix was a new coil. Silly me, previous coils either worked or they didn't.

 

[Mark_88]

Well, I did own an 89 Tempo for 14 years and only had problems with it a few times...and only the MAP sensor actually went bad (that I could fix at the time) and that was replaced with a $5 JY part...I didn't know anything about FI other than it started and ran for 14 years...lol

But I was more concerned about EMPs than actual breakdown of the truck...I read somewhere about ten years ago that one strategically placed nuke could wipe out 99% of all the computers and electronic systems...but, now that I think about it...who wants to be alive and trying to drive with zombies and mutants running around trying to eat your brain?

My new strategy is to run right into the middle of the bomb and be done with it...

 

[alwaysFlOoReD]

But I was more concerned about EMPs than actual breakdown of the truck...I read somewhere about ten years ago that one strategically placed nuke could wipe out 99% of all the computers and electronic systems.

I'm under the impression that EMPs only effect electronics that are in use. Vehicles not running and spare parts would be fine. Of course I struggle with electronics so my impressions could be bass ackwards.

Richard

 

[adsm08]

36 years of experience with engines and you didn't think to check for a crack in the coil casing?

Once of the first steps in the test for rough running is to use a jumper lead to ground a screw driver and wave it around the coil to look for arcs.

 

[adsm08]

I'm under the impression that EMPs only effect electronics that are in use. Vehicles not running and spare parts would be fine. Of course I struggle with electronics so my impressions could be bass ackwards.

Richard

Depends on the type of electronics in question.

Solid state stuff like pen drives and EEC-IV computers would probably be OK. A computer hard drive would be toast.

So would ignition coils. They would likely burn out or exploded.

 

[a31ford]

ADSM... think "Old school"... EVERY thing I have worked on (until the last couple of years) had the "good old" round coil in oil type,

Hey, even an old fart like me can still learn.... it just takes 10 times as long... what where we talking about ?

Greg

 

[Tedybear]

Mine fried the one day and it wouldn't even start. So when it finally did start? I'm mumbleing about how much of a PITA it's going to be finding an intermittent issue...and then the SOB zips me while doing a wiring wiggle test.

No cracks, nadda. Actually had enough kick to trigger an arc with a wire pulled and set next to the ground. Just not enough kick to fire the darn plug! But it sure did kick ME in return. It was arcing through the section where the core runs through the middle area.

S-