5.0 1980 f150 2wd c6 2150 everything has been replaced except tranny.
I recently experienced some hard starting when engine fully warmed up as if timing was out. I went to check timing when I pulled in my driveway. I had shut the engine off, popped the hood, and began hooking up my light. While doing this I could hear a high pitched whistle sound from drivers side of engine bay. It sounded like a capacitor was discharging, or a pin hole in a hose. I searched with my ears and it seemed to be coming from the ignition module. I replaced it about 4 years ago. I had to get a new/old harness because my original was shot. My question is about the ignition module. I like that it just always works, and when it starts to go, it lets you know by the engine dying. It restarts and you go on about your way and 2-3 days later it will do it again, so you replace the module and it never happens again. Am I correct in this notion that I will always get a warning like I described and has anyone heard the module whistling like this when key is out engine off, and is this a sign that it's time for another one? Sorry for such a long-winded post.
Also, my craftsman timing lite has the plug-in connector for the leads and I need to solder them in and bypass the connector because I couldn't find that sweet spot to hold it long enough to get a glimpse of my timing mark. I just manually increased idle by turning distributor clockwise a hair. Was this the correct way? I mean when it's hot and not starting real quick sometimes is it because it's too advanced, and thus idle is lower? Or my question should be, "Does increase in rpm happen from retarding or advancing? Thanks for any help.

 

An increase in idle RPMs is usually associated with an advance in timing. Regarding the high pitched whistle... sometimes after shutting down an engine, if the A/C was being used, a whistling sound can be heard as the pressures equalize.

 

Thanks for replying. The whistling can't be from the ac since it was removed just before I bought it. Higher rev is advanced-okay. That's good. I had it at 9-10 (sticker says 8) Drives best at about 12 degrees btdc.

 

Has nobody ever heard a high pitched whistle like a television set makes coming from the ignition module when the engine is off?

 

Not me.
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Not since the days of of our old Zenith console, tube TV (back when a test pattern appeared after 3 am when stations went off the air)...maybe post a video with audio ?
Seems like pressure is being relieved from "something". Another set of ears/eyes near the engine compartment while it's shut down could help.

 

Doesn't the power brake booster have a one way valve in it. If defective it could release vacuum when you shut down. Just a wild thought!

 

From your name you should know.

 

I like what you're saying. I'll get a long wrapping paper tube and try to zero in better to the sound. I'm old and don't hear or see well any more.

 

Either way, I should be able to wiggle that valve and see if the sound changes.

 

Does the noise happen every time? What if a spark plug was loose or the ceramic insulator wasn't sealing properly to the plug base? An engine shutting down will generally come to rest against the rising compression of a cylinder. If that cylinder had a leak, you might get a whistle you couldn't hear otherwise.

Unless all the plugs were leaking, you wouldn't get the whistle every time. That's why I asked about that.

 

It does or sure when it's warm/hot but I'll check in the a.m. Thanks for the response. I can now wonder about a bolt I drilled out of my timing chain cover/block during a recent water pump install. Your spark plug comment has opened my eyes further while opening my ear(s) with a cardboard tube. Hmmmm

 

Forget the cardboard tube or mechanic's stethoscope for diagnosing noise. I've had a Steelman EngineEAR for years and swear by it:

EngineEAR

I think one will set you back about $75 on Amazon. The microphone is so sensitive (and adjustable), I was even able to hear AC refrigerant leaking from a pinhole in the evaporator.

Steelman also makes fancier and more basic versions:

Listening Devices - Diagnostics

I'm very happy with the version I have. If you want to get one, I'd suggest sticking with the full cup headphones. I'd imagine they block ambient noise better than the earbud or Walkman style.

 

It's me that whistles not my truck. I'll never forget the first time I heard a whistle coming from a car, a beautiful 1950 Ford convertible. Asked my buddy "what's that whistling noise"? He said " Supercharger". Boy did that thing waste that new 58 Impala.

 

I just realized I haven't heard that sound in a while. Since, I replaced the radiator that has had a pinhole leak near the top. It always leaked down to a certain spot. Then, held it at that level. Never have used the overflow reservoir, even though the hose is running to it. I'm just going to assume it was the pinhole in the radiator. It had to get hot to hear it. Glad it's gone. The new radiator, from Autozone, sits about 1/4" higher and won't allow the top brackets to sit flush. Still doesn't dump into the overflow either. It's always something.