Hi All,

I have a '63 F-100 with the 262 inline six (big brother to the 223). It's always started right up when cold but lately I have to crank it a long time before it fires up. Once it starts is runs good, and once warmed up it has no problems starting.

I'm hoping you can point out the most likely things to check. Here's some pertinent info.

-The motor has not been rebuilt lately, if at all. It runs good but does have low compression in every cylinder- 80-90lbs.

-It has the pertronix electronic ignition module- installed this summer. Installing this did not make a noticeable difference, but then again the points it replaced were not old...

-The fuel pump is new, as are all the fuel lines and fuel filters. The stock fuel pump has been removed.

-I have a spare carb, the exact same model. I have swapped carbs with no change, so I think I have ruled out the carb. I swapped carbs around earlier in the year to diagnose another problem, so I know that both carbs run pretty much exactly the same.

-The timing is set per spec (6 deg. advance). Also I tried advancing it a little past this, with no change.

-Yesterday I inspected the plugs and they looked okay-not fouled. I believe these plugs have less than 3,000 miles on them. The wires are two years old, and also have less than 3,000 miles on them. Same with the coil- two year old NAPA coil.

So... any thoughts on how I can diagnose this?

Thanks!

Phil

 

have you got a spare coil laying around? if so, i'd try it.

also- make sure you're getting the proper amount of voltage (12v) at the coil during starting. maybe the wire which bypasses the resistor during cranking is giving you trouble.

 

Thanks. With my multimeter, how to I check the coil? I don't have a spare one.

 

Is your choke working properly?

 

if your voltmeter doesn't have alligator clips, you may need a helper.

black lead on a ground, red lead on the coil + terminal.
while cranking, you should have full battery voltage- ~12 volts.

 

Dphillips, My choke is manual and is working.

I checked with the neg lead of my multimeter on the battery negative post and the pos lead on the coil Positive terminal, and got just over 7 volts when cranking. Does this sound like a bad coil?

 

I checked the resistance on the coil also but I'm not sure how to interpret the readings... With the ohm scale on the multimeter set to "200" I get 1.8 between the pos and neg terminals. With the scale set to "20k" I get 9.5 if I bridge the pos terminal and the big center wire post. Mean anything to anybody?

 

So is my 7 volts while cranking (Post #6) a sure sign of a bad coil?

 

Doubt if its the coil if it runs fine afterwards. Probably something simple like the quality of fuel. If the engine has not been run for a week or so, today's fuel tends to evaporate more quickly out of the carb in the needle n seat float area. Try the next cold start with a shot of starting fluid (the type with upper cylinder lubricant) into the carb and watch what happens

 

I think it was the coil... Long story short, I replaced the coil with an Accel performance coil and it's doing much better! The old coil, a NAPA stock replacement was only a couple of years old at the most. I'm wondering if the Pertronix ignition hastened it's demise...

 

i would be investigating the wiring. you should be seeing a lot more than 7 volts while cranking. the higher-performance Accel coil may be hot enough to overcome the issue, but your underlying problem may still be there.

there should be a wire from the "I" terminal on your starter relay which runs back to the firewall, and ties into the wire that goes to coil +. this wire would give you the full 12v while cranking.

 

Thanks- I will definitely check that out! I had some sluggish starts after my last post so I will investigate further.

 

here's the diagram:
http://image.mustangandfords.com/f/2...em_diagram.jpg

in your case, the "quick disconnect" is the plug that goes through the firewall.

 

Thanks! I did a quick visual and the wiring looks good... Any suggestions on how I troubleshoot?

 

the order isn't super-important, but here's how i'd do it.

1. check voltage at the "I" terminal with engine running
it should be ~9 volts. this is coming from the key switch, through the resistor wire, through the firewall plug, to the terminal.

if you've got ~9 volts here, it means the wire from the "I" terminal to the firewall plug is good, and also that the resistor wire is working.

2. check voltage at the "I" terminal while cranking
it should be ~12 volts. when power is applied from the key switch to the "S" terminal (to crank the engine), the "I" terminal is powered as well. since the wire on the "I" terminal runs to the firewall and then ties into the coil + wire, you bypass the resistor- which gives the coil full voltage just long enough to start the engine.

if you've got ~12v on "I" during cranking, then the relay is doing what is supposed to.

i don't want to get too far ahead, so i'll stop here- let us know how it goes.