1971 Datsun Truck - Need Help

[1971tantruck]

truck starts sometimes runs for a minute then dies why

[mrbigtanker]

You getting gas constantly.

[datzenmike]

You need fuel and spark to start and run an engine.

 

Check the fuel level is at the line on the glass front of the carb. If full than it's at least getting that far.

 

Is the choke plate closing on the carb?

[TENDRIL]

lolz

[DanielC]

Engines are simple.  Compression, Ignition, Fuel.  All three, at the right time, and the engine runs.  Millions of engines prove that everyday.

I am guessing you do not have a compression tester.  Does the engine have a rhythmic sound, like four cylinders getting hard to turn, in order?  Or does it just spin freely, with a noticeable difference once every four counts?

 

If it has a nice rhythmic sound, crank it a little, then go and smell the exhaust pipe end.  Smell gas, suspect ignition.  do not smell gas, suspect carburetor.

[1971tantruck]

carburetor has gas there is spark

[wayno]

truck starts sometimes runs for a minute then dies why

Does it run good for that minute, or does it run like crap?

How long before you can start it again, and how long do you have to turn it over before it starts again?

When did it start doing this, after you changed something?

Is the truck new to you?

What did you do to determine that it has fuel?

[1971tantruck]

runs like carp sometimes right away sometimes slower in december it died then i change the timing chain and gear had truck for 6 years carb has gas in sight glass

[wayno]

Have you ever changed a timing chain/gear before on one of these engines?

When you tore the front off the engine, was it at TDC before you started?

Did you have to play with the distributor timing to get it to start the first time, and was it slow to rev?

[TENDRIL]

sounds like a spark problem did you check with a timing light that #1 is firing somewhere between tdc and 10btdc, even if its just turning over, mark your pulley with a paint pen i use red for tdc and white at 10 btdc 

 

 

have you had it running since the timing chain replacement?

[wayno]

How long has the gas been sitting in it?

[1971tantruck]

new gas first time on a datsun  put one on a Plymouth all marks were lined up yes and yes

[TENDRIL]

so you have had it running after the new chain?

 

 

and than it just took a dump?

[Tristin]

runs like carp 

 

[1971tantruck]

i also put a new distrubuter on it

[1971tantruck]

the intake values will not adjust

[wayno]

If I have time tomorrow I could come over and help you, but I would start from the basics, I am assuming you live in eastern Portland.

[1971tantruck]

i live in Milwaukee Oregon  i have to work tomorrow

[Fat510]

I didn't know there was a character limit lol could you be more elaborate when describing?

[wayno]

You need to start at the start, turn the engine to TDC, then remove the valve cover and check to see if the cam lobes are at 10am and 2pm, then remove the distributor cap and look at what post the rotor is pointed at on the cap, on an L16 it should be pointed towards the upper radiator hose outlet I believe, that post should lead to #1 plug, firing order is 1, 3, 4, 2 counter clockwise, it really doesn't matter which post the rotor is pointed at, as long as that wire goes to #1 plug.

All the valves should have about 10/12 thousands clearance.

[RatVonDude]

runs like carp sometimes right away sometimes slower in december it died then i change the timing chain and gear had truck for 6 years carb has gas in sight glass

sounds like a stock Hitachi, have you tried another carb?  Those things are a bitch to square away, 

Had a similar issue and it turned out to be a vacuum leak under the intake mani.  

[1971tantruck]

ok  i will work on that thank you for your help i need to go now i have to get up early for work

[1971tantruck]

it is a stock hitachi carb yes they are hard to get square this maybe the problem vacuum leak

[RatVonDude]

could be a combo of both, I even had my Hitachi professionally rebuilt and it still didn't run right. Try to get ahold of a weber 32/36 if you buy one get it from Redline not weberdirect you want the one made in Spain not china, do a rebuild from the intake up using the correct  gaskets I would recommend the manual choke.