Rebuilt 350 won't start
 

I am a noobie to engine rebuilding. Read a lot of books, watched videos, and read forums on rebuilding engines. Got a used 350 2 bolt and rebuilt it, new pistons, vortec heads, cams, intake. Reused distributor,Carter carb, mechanical fuel pump from my 305 engine. Now engine won't start. It will crank and sounds like it wants to start. Once in a while it will start, spike to about 4,000 RPMs and then die. If I play with the gas nothing happens. I think it is a timing issue. If I turn the distributor clockwise it just cranks. If I turn it counter clockwise then it sounds like it wants to start, but I maxed out on how much I can turn it. Reset the distributor and no matter which way I turn the distributor it still doesn't start, but it still sounds like it wants to. Any suggestions on how to trouble shoot this. Thank you for your help in advance.

Start at ground zero, find TDC and make sure your rotor is pointing to that post on the cap, looking down on the motor it would normally be at 5 o'clock, but doesn't have to be, as long as the rotor is on it. Try that, then come back if it doesn't start, we'll talk about cam timing and valve adjustment. Give up a little more information on the build.

Also, check to make sure you're getting fuel to the carb. Is the accelerator pump shooting gas into the carb throat?

Because you're new to this, pull the driver side valve cover and turn the engine over until the TDC line on the damper and the TDC mark on the tab are aligned and be sure the valves for cylinder #1 are both closed and not 'rocking' as you move the crank back and forth from TDC. If the valves are rocking, the engine is 180 degrees out and needs to be rotated another turn at the crank, then it'll be right.

Once you have the engine on TDC w/#1 "firing", advance the distributor by turning it CCW about 3/4" or so past the terminal to #1 plug wire- this is just an estimate, you need the timing to be advanced a good bit to start and run easily for the cam break in (2000-2500 RPM varying the RPM for a half hour or so).

Don't be afraid to give it a quick shot of starting fluid to kick it off. Not too much, and also not too much gasoline from the accelerator pump- you don't want to wash the oil off the cylinder walls.

Lastly- you have to be sure the damper line and tab are telling the truth. There are three commonly found damper/tab combinations that can get screwed up, so you need to be sure.

DETERMINING TDC will allow you to be sure the timing tab and damper are correct for TDC.

MAKE A TIMING TAPE to see what the total timing is, w/o needing to use a dial back timing light.

68NovaSS-I am pretty sure the rotor is pointing to the number 1 post. I will double check on that.

Crownver-Yes I am getting gas at the carb. When I pull the throttle linkage I can see and hear the gas coming out of the jet.

Cobalt327-I will check TDC via the rockers. Maybe my timing tab with the damper is off.

Sounds like you may be a tooth off maybe. As turning it CCW advances the timing and you said this is where it almost started. If you want to prove it you can move the wires 1 hole clockwise if you dont feel comfortable moving the distributor. This is not my recommend way to fix it but it is an easy way to prove the issue. You can use Cobalts method to find tdc and look under teh cap to see where the rotor is pointing or you can pull #1 plug put your finger ocer the plug hole and bump the key until it blowsur finger your finger off the hole then bring up the timing mark by hand. Then check the rotor to see where it is pointing. On some cars pulling the valve cover can be a task.

What do you mean by it spikes to 4000 RPM? It`s revving that high without your foot on the pedal?

Remember, Suck, Squeeze, Bang and Blow.
You need fuel, Compression, ignition (that includes proper timing) and exhaust. You have all that? It will run.
I would check timing, maybe you are 180 out? and valve adjustment, too tight or too loose.

I know this may sound crazy, but I had an exact same problem about 20 or so years ago. Tried everything I could thinhk of,. and a few other tricks from different folks.
In the end, what the problem turned out to be was a mix up in the cam I got sent. It was a Marine cam for a boat engine which turns in the exact opposite direction to an automotive engine.

Like I said, could be a long shot, but if nothing else works, take another cam, stuff it in, and try it.

It sounds like a timing problem, my old man would probably say , lift the distributer, turn it 180 degrees, drop it back in and crank it over. It'll either start, or back fire.

If it still won;t start after correcting the distributor, check each cylinder for compression. Remove all the spark plugs and kick it over with you thumb over the spark plug holes of each cylinder If any lack a strong compression push
the valves- rocker arms on that cylinder are adjusted too tight and the valves are always open. (no cylinder compression) If so loosen and reset the rocker arms using the up down method on the pushrods instead of the spin method to feel the 0 lash point.

Let me take that back, because it is trying to start I am playing with the gas pedal, it starts, RPMs jump, I try playing with the gas pedal to keep it running and then it dies.

The cam I have is an automotive cam. Got it at my local machine shop. Hmmm I kept the box will double check. If it is 180 degrees off would it still sound like it wants to start?

Got off work late today, will check on above suggestions tomorrow. But keep the suggestions coming.

This is how I always set my timing when dropping in a dizzy. First bring it up on the compression stroke then TDC. Drop the dizzy in make sure it seats all the way down. For firing purposes, turn the motor over by hand until you get to your desired timing. Take the #1 spark plug and ground it and turn the dizzy every so slightly until it sparks. Once it zaps, stop and tighten down the dizzy. Start it and time it with a light.

So finally got to work on my car. Took off the valve cover to check the rockers to find TDC with number one firing. Now it will start but idle is super rough, will run for about 5 or so seconds and die. If I give it gas, nothing happens, it doesn't rev up. Just idles rough and dies. Do you think something is wrong with the carb, could my timing still be off, or maybe my valves are too tight. At least I think I am making some progress. Any help will be appreciated. Thanks.

Bump
 

Any suggestions out there?