sudden death

[hollygreen]

Two days ago I made a midrange trip (248 miles).
Just one hour before arrival at home the engine started to fail then I checked the fuel pump, checked the fuel filter both of them were working fine and I was able to run another 20 miles then it just stopped completely. At night I worked cleaning the carb but nothing. It was midnight so I parked the pick up in a truck garage, at the next day I assumed that the fail was electrical so I acquired all the inner distributor pieces (condenser, distributor cap, rotor and the ignition point and just in case I replaced the ignition coil also), made all the changes and it worked just fine. I also noticed that the first three spark plugs had carbon fouling meanwhile the remaining three were burning fine. Well at last I fixed the problem and was able to get home but in the last two miles the fail started again but now it is a minor fail like a not working spark plug. My dad (previous and only owner till me) said that he never changed the ignition gear set (46 years) is that possible?. I will flush all the fuel system clean the spark plugs, check the point and if the fail still there I will be start thinking about the change of the ignition gear set .
Any comments or ideas will be appreciated.
Ford F-100 1967 240 engine 6 Line Cyl. mortorcraft carb 1bbl , motorcraft btf 42 spark plugs (3 months old) . Just changed the oil before the trip. New spark plug wire set (3 Months) , Ignition switch 2 years old .
Kind regards

Holly Green

[ToughOldFord]

How's the compression?

[hollygreen]

Hi Tough.

Compression is ok Itested just before the travel and it was runing like hell before the fail, last week I had a oil pan thread issue and I thought that the oil had been drained but the oil is Ok too. I made a total engine rebuilt ten years ago and the engine has about 7.000 miles on it I only use my pick up at weekends (when Im at home) so thats why the poor mileage in ten years. I realized something else, about two years ago I placed a Tachometer on the dash and the tach was working fine till the fail, when the fail happend the tach started to fluctuate. Before the fail the max RPM reached was 3000 (full throttle) and now it reach 6000 rpm full throttle, the idle speed is 1000 rpm and before the fail was 500 rpm (funny thing) that's why I still think it's an electrical problem.

[Mancar1]

With plugs next to each other fouling it could be a blown head gasket. Could be electrical. Hope u figure it out soon.

[hollygreen]

I checked the oil and is not contaminated, also there is no bubbles coming out from the ratiator cap (opened radiator cap), the smoke coming out from the exhaust is normal. thanks.

[sargentrs]

With the teach acting up like that sounds like a distributor problem.

[Nitekruizer]

What did your points look like when you took them out? Did they look burnt?

[hollygreen]

The point was burnt, I already replaced with a new one, I also replaced the condenser, rotor, ignition coil and distributor cap. the fail still remains but it is a minor fail plus the strange tachometer behavior. seems like a missing fire from some of the spark plugs. thaks

[motzingg]

burnt plugs usually means electrical, maybe when you replaced the points you screwed something up? didn't gap right or timing shifted?

[hollygreen]

I did all the procedure by the chiltons manual step by step, will check all the sistem again and lets see how it goes.
A new one when I checked the fuel filter and fuel pump it was almost night so I cleaded as I could, I checked now and there is a lot of dirt inside the fuel pump It could be another reason to boost the fail I think. Will flush all the fuel and clean the fuel sistem on saturday hopefully will have it running by sunday. Thanks

[tac]

Just a thought: Did you disconnect the tach? Depending on the type, it could load the coil down if it fails.

[ToughOldFord]

Just a thought: Did you disconnect the tach? Depending on the type, it could load the coil down if it fails.

Had that happen a few times myself.

[hollygreen]

Finally.
I flush the whole fuel system cleaned the carb cleaned the fuel pump, checked the timing (again), checked the spark plugs gap, re- wired everything from and to the ignition coil, and the failure was there a minor failure but was there. Then I followed Tough advice and disconnected the Tach then it worked perfectly thanks Tough. It’s hard to believe that the tach was the main cause of the problem I don’t see any logical reason between the tach and the failure but there it was. Thanks for all the comments and advises you guys did I really appreciate it. Thanks.