Your positive all your connections are clean and solid?

 

Hey Torqueking, have you inspected your dist. base plate to see if it has any play in it when your vacuum advance operates?
Try hooking up your timing light and watching your marks as you operate the throttle and see if you can see a blip on your marks that happens when you hear the engine misfire.
Clint

 

I'm going to check that out Clint, thanks for the suggestion. I've had the cap off and I've been playing with everything inside, and nothing I touch in there seems to make a difference, but I havn't done anything to the vacuum advance. Keep in mind I have an MSD Pro-Billet distributor, #1479, so the advance mechanisms are very different from factory distributors. If this doesn't get any better, I'll just send it back to MSD and let them handle it.

The funny thing is that my voltage reads 14v at the fuse box, and it's a very steady reading.

 

my suggestion is to go in the truck and bring your took box...open the box and get out some good grade black e;ectrical tape and tape over the light...lol but seriously i had this same problem with my 5.8L windsor motor and it was the water pump making that weird noise...its like a whining or deeper squeek but not that loud...it drove me nuts looked everywhere for it. oh and the autozone thing....bro we have discount auto parts here in Fl and they are the same way about their parts..my poor dad had bought an alternator for his lincoln and i replaced it for him at our house, he took it to ford and they wanted an arm and a leg. well after replacing this thing it lasted 2 days before melting the terminal plug thats hardwired into the cars wiring harness. needless to say we changed this thing 5 times in a month and 1/2 when i finally said thats it...took it back and they said we could only exchange it i was like no you need to refund the $120 we paid for this peice of crap we have had to pay a mechanic to change this thing out 5 times now im not goin for 6 (im the one who changed it but you know how much it would have been if a mechanic had done it) to which the store mgr refunded the $...hope you track down the problem man but try the vacum advance and listen to that water pump

 

Hey TK...did you ever pick up a stethascope? I found one yesterday at Murrays for only $6.99! I can't wait to try it out.

How about an update on where you are on this? I was thinking, did your truck have an alternator light? Most F-series trucks came with a rinky dink gauge cluster. Or was it the oil light flashing?

From what I read, you still have the noise and the random misfire. Any luck yet? Just checking...

 

My 90 ford bronco fuel pump whines like a 2 year old always has since the day I bought it!

 

Yeah, actually the noise is still there, and the "ALT" light still flashes upon decel or idle. The noise seems like it's getting louder, but it's getting harder and harder to pinpoint the location of it. Thanks for checking in, I still havn't figured this mess out.