Scorpio Game Show - Name That Failure

[DPDISXR4Ti]

For the first time, the Scorpio came home on the back of a flat-bed today. JuleScorp went out to the reservoir and four hours later I got a text... "Car won't start!"

ScorpTow.jpg (538.76 KiB) Viewed 15303 times

It was cranking over fine, so I grabbed a PCM, distributor, and my toolbag and off I went. Checked the Schrader valve upon arrival and got fuel, so mostly ruled out a fuel problem (not fully - it could be weak pressure). Swapped in the spare PCM, if only because that's easy. No surprise, no change at all. I immediately got mad at myself for doing that before pulling codes - too late - moving on. Carefully noted the clocking of both the distributor and rotor and then removed, leaving cap and wires attached so I didn't risk screwing that up. New (sorta known good) distributor installed and no change - cranks forever without even a hint of firing.

Give up - call for a tow.

Better diagnostics to now commence...

[my8950]

Easy to do, spray in some starting fluid while cranking and see if it hits, if not, then spark.
Sounds like no spark based on what you have stated, so possibly PIP in the distributor?

[Ed Lijewski]

FP relay/fuse check.

YMMV

[DPDISXR4Ti]

Sounds like no spark based on what you have stated, so possibly PIP in the distributor?

Did you miss the part about swapping in a new distributor?

I'm pretty sure fuel is fine - aside from fuel at the Schrader valve, I was smelling fuel after an assortment of cranks. I wanted to verify pressure tonight but found the fitting for my gauge would not clear by the intake manifold. Never heard anyone mention that before. For now, I'm going to assume fuel is fine - new pump and filter were installed by Darren maybe 20K miles ago.

Since I've got spares, I'm going to try swapping in a new coil tomorrow.

[andyofcolumbusmerkur]

I bet the tow guy thought it was pretty interesting. I am thinking you will find some loose or corroded connector when messing with it.

[Ed Lijewski]

I bet the tow guy thought it was pretty interesting. I am thinking you will find some loose or corroded connector when messing with it.

Yeah...the ECU ground at the battery negative post for one.

YMMV

[brokencase]

If no spark, and not the distributor, then the coil?

You should have pulled codes. You are too quick to go into swap mode.

You are in luck Wholeseller closeout at RockAuto for Scorpio ignition coils. $6.55

Sometimes my Scorpio won't start after a heavy rain. Did it get wet?

I think I am going to put a thin smear of silicone around the base of the distributor cap to keep the moisture out

[Ed Lijewski]

Sometimes my Scorpio won't start after a heavy rain. Did it get wet?

Duh:
.
.

Screenshot_20230816-201928_Firefox.jpg (86.99 KiB) Viewed 15116 times

YMMV

[DPDISXR4Ti]

If no spark, and not the distributor, then the coil?

You win! Replaced the coil tonight and it started right up. Over the years it's been suggested that the coils are very reliable and "never" fail. I've now had two of them fail - the other was on my truck a few years ago. I'll certainly add coil to my parts cannon if I'm ever again needing to try to do a road-side repair.

I searched a bit and can't find a way to bench test these coils. The failed one had identical resistance to the good one.

[Merkur]

I searched a bit and can't find a way to bench test these coils. The failed one had identical resistance to the good one.

When I have had coils fail in the past (admittedly on other non Merkurs), they test OK with a regular meter but it's the insulation that breaks down. The spark happens, but it's inside the coil instead of the spark plug. This can be either in the secondary winding, or a micro-crack in the HV receptacle. Sometimes you get lucky and can see the arcing in a dark garage when you crank it, or you can see a 'trace line' on the coil itself. To check it and do a real failure analysis, you'd need a Megger tester.

Paul

[DPDISXR4Ti]

Good info Paul. Given how easy it is to swap a new coil in, it's definitely something that we should be carrying with us - at least for any lengthy trip. The nice thing too is that the coil body doesn't need to be grounded, so for test purposes you could easily remove the quick-connector and try a new one without even removing the old one.

The funny thing is that just a few weeks back I started exploring the idea of using the EDIS distributor-less stuff from the later 4.0 engine. Doing so would mean that the distributor, PIP, TFI, and ignition coil all hit the bottom of the trash bin. Unfortunately, it's a more involved process than it is with the Lima 2.3. The biggest reason is that the 2.3 migrated to DIS first vs. EDIS on the Cologne V6, where they skipped DIS entirely.

[Ed Lijewski]

I think the issue wasn't the coil itself, as testing them by the Service Manual confirmed, but a deteriorated/cruddy/even loose connection of the primary 12v wire at the coil. This isn't an unknown issue after over 30+ years.

A few years ago I parked my Scorpio at a Home Depot and on return the engine wouldn't fire. On that trip I had no tools with me, so after opening the hood and looking around and finding nothing out of place I looked at the coil and decided to check the two wire connections there, cleaned them up with a small knife blade from my pocket, and reinstalled the connector. The engine then fired and ran normally.

Some time prior after driving an XR to an ATM and returning to the cabin the engine wouldn't fire. In this instance I found the two wires at the coil were loose in the connector. I pressed them firmly onto the connector, and the engine fired.

Crud/oxidation on connections open to the engine compartment ambiance after 30+ years is a no-start/no-function issue waiting to occur. Pull out a few fuses and relays and see the accumulations on the male prongs.

YMMV

[brokencase]

The ignition coil used on the Scorpio was common to several Ford models of the period.

Accel makes a high output version. Its a little pricey, but is well built and sealed and probably will last a long time.
https://www.ebay.com/itm/133353306119

A while back I bought a "high output" coil off of ebay for about $15. It was basically a clone of the Accel unit, but was black instead of yellow.
I kept my original as a spare.

The outfit that sold the coil also offered a K&N clone air filter that I also bought, which I think was around $25.
Sadly that outfit is no longer selling stuff on ebay (I just checked)

The $6 & change coil from RockAuto is a good deal for a new coil.

[Ed Lijewski]

Equal coil deal here too:

https://www.ebay.com/itm/185428305984?m ... media=COPY

YMMV

[brokencase]

It was a game show.

Monty - What do I win? I'll take what is behind door number two.