NO START issue

[sammysamm]

My truck was running fine a few weeks ago and now it will crank but not turn over. Electrics are all fine . I have new battery . New alternator and starter  recently. Im not sure if im getting gas to the engine. Whats easiest way to check that ? -should i pull off fuel hose from carb to check?Also if im not getting fuel how do i go about fixing that?   Thanks , Chevy 1981 454 c20 stock camper special.

[VileZambonie]

If the engine cranks then it is turning over. What you are describing is a crank, no start or engine cranks but will not run condition.

First thing to do is check for spark.

[Ronno6]

Easy test is to dribble a little gas down the carb and see if it fores then.
If so, lack of fuel is the problem.
When my truck sits too long the fuel pump loses its prime, and I funnel some gas back down
the fuel live from the carb. (Easy enough if you have rubber fuel line; if steel, not so easy..)
That primes the pump and all is fine.
You should place a fuel filter inline ahead of the carb.
You should see gas there if the pump is working (or lack of gas if it is not...)

[sammysamm]

Okay so I just put in new batteries how do I check for spark? Truck recently had a new distributer cap put on.

[sammysamm]

My experience consisting of putting a new alternator and a few new belts on the 454. I am a rookie so please keep that in mind when explaining, thanks a lot

[JohnnyPopper]

Ok, so your engine turns over when starting but does not fire off and run, right?

Fuel: with the air cleaner off, look down the carb and pump the throttle. See if there is any gas spraying down the carb. If no gas, then do the next thing.

While cranking the engine over, pour a small amount down the carb, like a few drops per second. Not too much. If the engine acts like it wants to start, you have a fuel problem.

First look for filters being clogged. If you cant blow air through them, they are clogged. Also, assuming it's a Rochester Quadrajet, there is a fuel filter in the Carb, at the point where the fuel line connects. The metal fuel fitting is 5/8", screwed into a big nut that is 1". Using a 1" open end wrench to hold the big nut in place, break the 5/8" loose with  a quick but firm snap. Once the fuel line is free, remove the big nut, and you will find the filter inside.

Ignition: If while cranking the engine and dripping gas down the carb you get no response, like the engine wants to start, you might have a ignition/spark problem.

Pull one of the spark plug wires off a plug, and move the end to an open area. Place a regular philips head screwdriver into the plug socket, and get it near a metal surface on the engine.

While holding the screwdriver by the handle not the shaft, have someone crank the engine while you hold the screwdriver about an 1/8 of an inch away from the metal surface, (bracket, pipe, tube etc). If no spark jumps between the screwdriver and the engine, you have an ignition problem.

You will need to use a meter or lamp tester to test voltage at the distributor cap connection, and maybe back to the ignition switch.

Post what you find, there are other things to suggest if that does not work.
 

[sammysamm]

Ok im going to try that in the morning. By the way when i spray a bit of engine starter it will crank over a few times and die. So guessing its fuel prob.

[Irish_Alley]

im going to tell you a little safer method of testing for spark and one you can do by yourself. take a plug out and use a set of jumper cables ground one side to the battery or a good ground and attach the other side to the threads of the plug and reattach the plug wire and move it to a spot where you can see it from the seat and crank it over

[JohnnyPopper]

Come on Irish!

Sometime is fun to see an involuntary un-happy dance!

Clever idea if you're by yourself, Thanks!

[philo_beddoe]

You could diagnose it correctly or just keep replacing parts until it starts. Carb, fuel pump, etc...  lol
Kidding...
Sounds like a fuel delivery problem. But trust the feedback from the experienced ones on this site. You'll soon know who they are.