1951 gmc wont start

[bigred1951]

ok guys my 51 gmc has been sitting for a couple years. Been trying to get running lately but couldnt get it to start. So today went and got a new set of points and condenser and put in it. Well it started right up and ran fine for a minute then died. Well it wont start back even if you pour a little gas down carb nothing. It is getting spark at the coil. So im pretty much stumped. I put a new fuel pump on it a few years ago so i would guess it would be fine i didnt  pull the line to check and see if it was getting gas but it should still pop off by putting a little down the carb. Any ideas?

[thecfarm]

Is the rotor button going round and round?

[sprucebunny]

Some new gas with Seafoam in it ?

Is there a drain on the carb ?

Is it a 235 ?

[bigred1951]

now that you mention it i also put a new rotor button on it. Yes it spins round and round. Its a 270 straight 6

[dgdrls]

seems the spark is not getting to or leaving the distributor,

cap still good?  distributor wires, coil wire, carbon button in the center of the cap
making good contact with rotor

Rotor ??

you'll get it,

DGDrls

[bigred1951]

It is getting spark at the coil and the coil wire but im wondering if it is getting spark to the points or plugs. Ill have to check it tomorrow or the next day. Its gotta be somethin simple. I did get a new distributor cap to put on it but when i got back and looked it was the wrong one  >:( go figure

[yukon cornelius]

they probably gave you a 235 or 216 cap. you might check your point gap again. I have had them slip after I thought they were tight. those carbs really gunk up after sitting a while also. those 2 things are where id start. I wish I had my granpas 50 gmc back! or my 53! best looking truck ever made!

[Southside]

Maybe it's just tired!!!  You think you will jump out of bed at that age? :D

[redprospector]

Maybe it's just tired!!!  You think you will jump out of bed at that age? :D

I certainly hope so.

[r.man]

Spark strength is important as well. If you have a spare spark plug, pull the tab off the end so the spark has to jump from the electrode to the side. If it won't it is probably too weak to run. Also check for consistent spark, does the spark rhythm seem right and consistent. You should give the engine the finger compression test if you have the plugs out in case you have multiple valves sticking.

[Corley5]

Today's condensers are junk.  Your new one may very well be bad.

[sprucebunny]

Ya, I recently had the same sort of problems with a 1955? Chrysler 230. I decided I would replace the points and condenser with an electronic version. It was not made by the company I got the last one from (for a Ford 300/6 ) but I did find one from Pertronix and when I finally recieved it, it worked Very well.
Even though I had gotten the machine running while waiting for the electronic unit,,,, it starts much faster and I expect it to start reliably long after I would have had to fiddle with the points again.

[scsmith42]

With the key on, check the voltage at the coil - it should be around 9 - 10 volts.  If you have 12V -14V then your problem is the resistor shorted out and causing the points to arc over.

[36 coupe]

A 51 GMC is 6 volts unless the 12 volt turkeys have messed with it.Friends and I were starting Model A Fords when we were 14 years old.

[bigred1951]

well i believe its still the 6 volt system. 12 volt battery but there is a resistor on the firewall. Still running the 6 volt generator. My papaw bought the truck off my stepdad around 2000 or so for 500 bucks. He rebuilt the brakes and he taught me how to drive in it on the main road when i was 12. Imagine a 12 year old on the main road in a 51 gmc 2 ton with a 14 ft flatbed no power nothing, double clutch and air shift 2 speed haha. Well he passed away when i was 14 and left the truck to me. I have since had the rad recored for $700  then a new water pump, then fuel pump. Ive sadly neglected it over the past couple years and its just sat not touched. So ive finally decided to get it back in shape

[redprospector]

well i believe its still the 6 volt system. 12 volt battery but there is a resistor on the firewall. Still running the 6 volt generator. My papaw bought the truck off my stepdad around 2000 or so for 500 bucks. He rebuilt the brakes and he taught me how to drive in it on the main road when i was 12. Imagine a 12 year old on the main road in a 51 gmc 2 ton with a 14 ft flatbed no power nothing, double clutch and air shift 2 speed haha. Well he passed away when i was 14 and left the truck to me. I have since had the rad recored for $700  then a new water pump, then fuel pump. Ive sadly neglected it over the past couple years and its just sat not touched. So ive finally decided to get it back in shape

Haha. To imagine that I need only to think back to a different place in time. I learned to drive when I was 12 in an old GMC "Bubble Nose" 2 ton truck with a 20' grain dump bed. I believe it was a 52, but I could be mistaken. Heck, it even had an air conditioner that hung in the window, and you poured water in it.  :D I was up town.  ;D
It's a different world now though.

[sandhills]

Not to many 12 year olds would even know what a stick shift is now a days let alone a 2 speed rear end.  I let my 12 year old daughter drive us to the lake last weekend to meet up with my wife, pretty much all back roads but there was a mile of highway in the course.  She did really good and was grinning from ear to ear the whole way, of coarse an '03 Trailblazer is a little different than a '51 GMC  :D.  I'd much rather see kids learn that way then just go pass a test when they turn 16 and think they know how to drive.  She does drive around the farm and our place a lot, I didn't just turn her loose and say go  ;).

[luvmexfood]

I learned to drive on a 67 Ford one ton. Four speed and power nothing. Hoss of a truck though. Dad sold it for parts and not a lot wrong with it. Only thing I hated about it was the bed was up so high. Hard for a short guy to sling them bales of hay upon it.