germeten

I bought a '95 Eddie Bauer F150 last year, it had some starting issues so I changed out the distributor, also put solid-core wires. The truck starts fine even when very cold, except when it's extremely damp outside, days of rain and snow-melt. My town has alternate-side street parking so not moving it any given night incurs a $20. ticket. Advice/suggestions needed.

Rusty but trusty

Check all your ignition wiring under the hood for condition, also your coil. Sounds like you have a wire getting wet and killing your spark. My old car ran on 6 of 8 cylinders when it rained or was very humid, turned out I had one cracked coil pack. Try pulling codes just to see if it's trying to tell you something. Take a good look at your coil, it may be getting moisture in it.

germeten

Thanks Rusty.

I erred stating it was a 96, is a '95. I bought this truck because I needed one and it ran and in much better shape than my trusty 85 Chevy (since crunched), and I really dislike it vs. my old one, from the power windows to the fuel injection, oddly placed manifold and difficulty to reach under the bonnet to do maintenance, endless "smart" sensors, etc. (Give me an 85 Ford any day.). Anyway I will take your advice, I suspect it might be the coil. It's very predictable and consistent, in wet weather it positively WILL NOT start.

1990 F350 4x4

This problems are tricky ----here's the place I normally start:



Connect voltmeter negative lead to distributor base.

Check battery voltage.

Turn ignition switch to RUN position.

Measure voltage at positive terminal of ignition coil.

If voltage is at least 90% of battery voltage, inspect ignition coil harness connector and terminals for damage, corrosion and dirt. If Ok, then check your TFI Supply Voltage circuit.

If voltage is less than 90% of battery voltage, check wiring between ignition switch and ignition coil. Check worn or damaged ignition switch.

germeten

Hi 1990 F350 4x4;

Thank you for your advice, I bit the bullet and ordered a new coil (price was right) to see if swapping it out helps. After that, I'm at a loss. Note: my distributor ('95) doesn't have a TFI box, but I noticed the coil has a funny capacitor looking thing beneath it, connected to one of the wires, possibly GND.

All I can figure is if it's not the coil, there's a short occurring in the primary wires somewhere, preventing the coil from getting juice when it's wet.

Idea; I bought a new distributor cap and this one has a vent plug. What if I ran a hose to it and pulled a vacuum from manifold? That at least should remove any moisture that might be occurring inside the cap.

1990 F350 4x4

You mentioned that primary wire and I'm thinking that's something to check out / eliminate as a source of the problem --- this leads us back to the ignition switch for example and I'm wondering if it's worth it to run some continuity checks on the actual switch --- pull the steering col shrouds, pull the connector off the ignition switch and check its pin pairs in the various position (ACC, OFF, RUN, START, etc).............

In RUN, you'd have continuity across:

A-1 and B-1
A-2 and B-2
A-3 and B-3
A-4 and B-4
I-1 and B-5

In START, you'd have continuity across:
I-1 and B-5
I-2 and B-1
STA and B-4
P-1 and GND
P-2 and GND

they do wear out and are susceptible to dampness, weather effects..........

germeten

1990 F350 4x4:

Thank you again, you sound like a trained mechanic, I have zero experience doing those tests, should I go buy a continuity tester kit from Harbor-Freight? What is the difference between RUN & START (vs. OFF)? I don't presume any continuity test can be done on the connector pins when the engine is actually running without killing the motor(?) (Sorry for being SO green at this, truth is I even have trouble disconnecting the connectors, their barbs are all different and I often break them for trying.) Last night the CHECK ENGINE light went on for the first time.

Rusty but trusty

Continuity is checked with power off. You are measuring resistance (ohms). Low resistance = good circuit, high resistance = bad circuit. Get a multimeter from Sears. They sell decent ones for around $40.
That is a good thing the check engine light is on. Pull codes and see what it's telling ya. (See sticky thread on how to do it)

germeten

Following up... a local mechanic convinced me to try a new cap, which made no difference at all (new distributor came with new cap, so I didn't expect any better.) Then I chanced to notice after a rain when I lifted the hood, a wet spot on a harness of wires running side and behind the engine, apparently water runs down the back of the hood by the wipers and leaks into the engine bay, directly on the harness. The current covering has crackled so I wrapped polyethelene over as much as I could reach, several layers, and shrunk it down with a heat gun. On top of that I split a piece of pool hose and put it over everything. Thought I might have it licked when... I'm now getting a "check engine" light and burning tons of fuel, stammers and runs like crap. And this is on a nice, warm, DRY spring day. Good thing: Autozone clerks gladly run diagnostics scan for free. Bad thing: They don't have the adapter or scanner for pre-1996 Ford vehicles. I looked on ebay for OBD1-to-OBD2 adapters, some are quite cheap, but pin-outs look nothing like what I've got (female tab receptacle, not pins at all); so... I'd like to save some money here, local mechanics here charge over $100 bucks just to run a scan. Do any of you have any suggestions?

memoniz

You could look on the sticky in the main section on how to check OBD1 codes as Rusty but Trusty said. It's just requires a wire to jump the connection and read the flashing lights. If you have a Haynes or Chilton's book, it will tell you what the code means or look it up on the internet.