why won't my truck start!! help!

[chevygrl68]

im getting really frustrated.. my truck was running great - then out of the blue it started running really rough & died. now it won't start up again. it'll crank over all day long but not fire. seems like it should be something simple but i have tried everything i can think of!!! im so confused right now.. was hoping somebody out there had an idea or could point me in the right direction on how to find the problem.

[71swb4x4]

Check the basics. Is it fuel related or spark related? A fuel pump can die suddenly. So can a coil. A lot of things can cause it actually. It's probably something simple, but you need to start narrowing it down.

[prostreetC-10]

When it comes to carbs, a motor starting and running are 2 different things. In order for it to start, it just needs fuel getting into the motor through and accel pump. What kind of carb? You should be able to take off the air cleaner and look into the carb with a flashlight. work the throttle by hand and see if gas is squirting into the barrels.

Since it started running bad then died, it's probably not the dizzy although anything is possible. If there is no fuel squirting out the discharge nozzle you have a problem from the tank to the carb. Could be a bad pump, line, filter......ect!

[cdowns]

points or hei? if points have you cleaned and set them latly? have you changed your air and fuel filters lately? cleaned and gapped sparkplug

[chevygrl68]

the distributor cap rotor points & condenser are all brand new. carb is a 650 holley - i did check & it is squirting plenty of fuel. spark plugs are also new - i pulled em after trying to start it and they're pretty wet. i thought maybe the coil was the problem so i hooked up a spare one i had laying around - no change. grrr! im really out of ideas at this point :/

[bigguy69]

is it getting power to the coil?

[hayhauler71]

Do you have spark out of the coil ? if not check power to the coil , if it has power but no spark the problem is in the dizzy most likely points.

[chevygrl68]

how do i test that?

[hayhauler71]

Originally Posted by chevygrl68

how do i test that?

First pull the coil wire from the dist cap. Hook up your test light to the neg side battery. Have someone crank the engine and try to get the spark to jump to the test light. Also if you put the test light on the neg side terminal of the coil while cranking the test light should flash. If you have spark out of the coil your problem is the cap or rotor If you have no flash on the test light on the neg side of coil when cranking problem will be in the points. Also make sure you have power on the pos side of coil with the key on.

[highperf4x4]

Originally Posted by chevygrl68

the distributor cap rotor points & condenser are all brand new. carb is a 650 holley - i did check & it is squirting plenty of fuel. spark plugs are also new - i pulled em after trying to start it and they're pretty wet. i thought maybe the coil was the problem so i hooked up a spare one i had laying around - no change. grrr! im really out of ideas at this point :/

From the sound of it, I'd say you have a problem with the power wire to your coil or the coil wire going to the cap. I recently had a similar situation with mine so I swapped it over to one of my old HEI dizzy's and now it's screamin! It was realy simple and it never ran this good.

[chevygrl68]

ok i just noticed something... i was looking in the carb & one barrel is getting fuel without me touching the throttle.. its like a constant drip. could this be the problem? it won't start because its flooded? how do i make it stop

[highperf4x4]

Yup, that would do it. I don't know what's dripping though. I'm not a holley guy. Could just be trash in the needle and seat or a hole in the float.

[highperf4x4]

I can tell you this though. You better pull the fuel line and cap it off or your crankcase will be full of gasoline by tomorrow morning.

[chevygrl68]

good lookin out.. thank you. im gonna go pull it off right now

[highperf4x4]

You're welcome and good luck. I would definitely start with the needle and float.

[RanchFlyer]

simplify things. All engines need 3 things to run. Fuel, compression, ignition. Step one on a no start is spray carb cleaner into the carb while someone else is trying to start the truck. If it fires then you have compression, ignition and the problem is fuel related. Even flooded plugs will fire on B-12 in a spray can. Step two if it won't fire on carb cleaner spray, check compression. Anything over 70 pounds should run, Not well but enough to putt around on fresh plugs. Step three If you have compression but won't fire on carb cleaner go to ignition.

Even with a carb dribbling fuel do the above and be sure you are on the right trail at the carb.

[chevygrl68]

sweet. thanks everybody! i think i at least have some direction to go now instead of just cursing at it i dont have a helper tonite so ill get at it first thing in the morning

[Dark Knight]

If it is flooded from the dripping, try flooring the accelerator while cranking on it. Should fire up. If that doesn't work, have a helper crank it over while holding a plug wire 1/2" from the exhaust manifold to see if you have spark. It's most likely an ignition problem. You should have +12 V on the coil while it's cranking, +5 or 6 V while it's running.

[AustinScott]

Good Luck... and let us know what happens....

[chevygrl68]

she's alive!! put the carb back on this morning.. it was really out of whack getting WAY too much fuel! but the truck finally fired up for me still got some adjusting to do but im really happy its at least running again. but im still curious... what would make it go from running great to being totally out of adjustment?

thank you all sooooo much for helping me!

[highperf4x4]

Usually trash in the needle and seat.

Glad to hear you got it worked out!

[RanchFlyer]

So glad to see that it is running. You may think about changing the oil. If the carb put that much extra gas in, it went somewhere. Always better to be cautious.

[67mbsc]

Originally Posted by RanchFlyer

So glad to see that it is running. You may think about changing the oil. If the carb put that much extra gas in, it went somewhere. Always better to be cautious.

VERY good advice!
CHANGE THE OIL and FILTER

[highperf4x4]

It is pretty good advice if your oil level suddenly rose. Just check your dipstick. If you've got extra oil now then you probably need to change it.

[crimespree]

i had the same thing happen with mine... someone i worked with moved the vaccuum advance hose from one spot on the carb to another. the motor i have has a distinct loping to it and when the hose was moved, everything seemed to "smooth out". a day of driving proved this to be a horrible idea and left me to tow my truck into my shop with my forklift. new plugs, new oil and new cap/rotor (just because i was worried they had been burnt up) it was still getting too much fuel. i should have known better than to let a weirdo screw around with my carb.