Hot Rods Another SBC that wont start - need help diagnosing

I apologize in advance for another "it wont start" thread, but I'm about to pull my hair out. I'm pretty new to all this, but I rebuilt a 283 last year and got it running pretty well about two months ago while sitting in the frame. Everything sat for about a month while I installed the body (model a) and reconnected the very basic wiring needed to start the motor, and now it wont start. I have everything connected exactly as it was (based on photos I took prior to disassembly). The motor cranks, I am getting spark (pulled the new plugs, cleaned, gapped, and visually checked for spark), and I've got fuel in the cylinders (wet plugs) after cranking. I haven't messed with the carb or the distributer since I unwired it. When its cranking, it acts likes like its maybe coughing on one cylinder. I've adjusted timing just to rule that out and it doesn't affect anything.

I dropped the coil about two feet onto the concrete floor while I was rewiring. I've checked the resistance and voltage readings on the coil and everything seems fine. I didn't think much about it, but could this be the reason?

The motor...
283 bored .60 over, new wires, new coil, rebuilt Mallory Unilite distributer, Rochester 2G carb, mechanical fuel pump.

Many thanks in advance!

 

loosen the distributor and turn it backwards and forwards slowly while cranking.

 

Starting fluid helps with troubleshooting a problem like this. If it will fire with starting fluid but not continue running than it pretty much locates the problem to fuel. If it wont fire on starting fluid, than you've got ignition system problems to sort out. Don't use too much at a time, or for too long, that could be detrimental to the engine. But just to help diagnose the location of the problem it is helpful.

 

Did you reinstall the distributer 180 degrees out, if so the rotor is trying to fire #6 plug and it's not properly timed.

 

In most cases the only way to get it running when the spark plugs are gas soaked is to replace them.

 

What Gary said.

 

I tried that. Nothing changes other than the cough goes away, but comes back when it set back to the original location.

 

I have not pulled the distributer since the last time when it was running just fine.

 

So you're saying I need to replace new plugs just because they got wet? I pulled them all out to clean and check them, but should I dry out the cylinders too? I was surprised by the amount of fuel that came out of the 3 or 5 cylinder when I pulled the plug. I rebuilt the carburetor, but I suppose it might have flooded.

 

Are you saying fuel ran out of the cylinders? I think you may have found the problem...

 

The plugs will be fine , just need to dry out, same with the cylinders. First concern would be how much gas is in the oil, pull the dipstick and smell the oil , if it smells of gas, drain oil and pull the filter and leave open, pull the spark plugs and give it a day to evaporate. You’ll probably have to have a look into your carb, needle and seat may need some attention if it’s flooding the engine that badly

 

Choke on or off. ?

 

Presuming the dist. is in correctly....have you checked the plug wires for correct firing order?
Possibly, one of those motor gremlins snuck in and re-arranged them for you
18436572 CW

 

change the oil and filter - as said by wanderlust above
An indication of how much fuel is in the oil may be to see if your dipstick is reading higher.
.

 

@myergin ,
Setting timing with out engine running.
Or timing light .
Pull all plug wire of cap .

Instal #1 plug wire on cap

Bring # 1 piston up to 10-12 degs
BTDC, mark on balancer to timing tab.
Power up Unlight
Have # 1 spark plug wire" END"
with a Air gap
1/8 from ground / metal ,
Slowly turn distributor , to Zero in
#1 Rotor to # 1 pole on cap.
When Rotor gets close to #1 terminal on cap you will Hear Snap /ark & see spark ,
Lock distributor down,
Now your timing will be 10 to 12 degs
BTDC ,
Check & install all wires on cap
& spark plug 's Fireing order
Clock wise on cap

spark plug gap .035 - .040

.020 to .030 gap on butterflies to bore

"""& DO NOT WELD WITH U -L Connected"""

 

I'm leaning more towards this being a "flooding" situation. When I pulled the plugs, a few of them literally "dripped" wet. Again, I know nothing about nothing, so I'm assuming this is TOO wet. Maybe it was just from me cranking on it for so long and dicking with the carb? Looked at the carb again and everything seems fine... float, needle, seat, all look normal. Maybe the Holley mechanical pump is overpowering the needle/seat in the 2 Jet, but then wouldn't the bowl overflow out the vent and not not into the idle circuit?

Either way, I ordered a regulator and a fuel pressure gauge.

Just a slight fuel odor in the oil. I pulled the plugs and I'm hoping to let everything dry out. I'll report back this weekend.

 

2G's are sensitive to too much pressure. Set the regulator for about 2 - 3 psi.

 

If you have strong enough spark, enough compression, and fuel, either you're flooding it or your timing is way out to lunch.

As Blues mentioned, is your fuel pressure too much for your carb? If you have fuel in your oil at all, I'd change it. What are your compression numbers? Could be your pushrods are too long and valves aren't closing or your valves are sticking. These are all diagnostic steps to figure this out.

That said, it does sound like it's leaning towards flooding.

 

I say it's dumping fuel out the over flow because of.... float too high.. or too much fuelpressure...... easy check.. look in the carb when you crank it over... theres so much fuel it doesn't atomize and squirts fuel enough that it drowns the plug...

 

fast easy check, put needle nose vise grip on the fuel line...only way to flood the cylinders is through the fuel line...float could be stuck wide open... eliminate the carb as a problem....bet if you let it sit and dry out it'll start... un hook the fuel line and fill the carb through the vent pipe it should start and run till it empties the bowl.... even if theres no spark, you can't fill the cyls with gas unless the fuel pressure is blowing past the needle and seat and just dumping way too much fuel...

 

With the plugs pulled you should crank the engine over to get any puddling gas out of the cylinders. Otherwise it might drain into the oil and create very thin oil viscosity! I'd certainly install the pressure regulator and gauge before trying anything later, but also consider a fix for the carb if pressure shows to be less than 6 lbs. when the gauge is installed.

 

If you have that much fuel in the cylinders, you might remove the air cleaner and look down the carburetor, with a wide open throttle, and see if there is fuel puddled in the intake.
It's not going to want to start with an intake full of fuel and a cold engine.... you have to get it dried out....plugs out and throttle propped open and let it all evaporate off
Troubleshooting at long distances gives you lots of rabbit holes to go down and since you said it was running, I'm leaning to overwhelmed with fuel...but I know nothing
good luck

 

This has been my experience as well. I have had some success cleaning the plugs and heating the ends over a flame on a stove, but more success by just replacing them with new. After wasting a lot of time dicking around with washed out plugs then installing new and having hte engine fire right up it's worth it to me to avoid the wasted time and the aggravation and just replace them. Your choice.

 

^^^ Here in Arkansaw we spend time cleaning them. Then sometimes buy new ones, but never throw one out till it breaks.

 

Go back to the basics.

If the cylinders were that flooded with fuel, I believe I would put a couple squirts of motor oil into each cylinder with a squirt pump can, and spin the motor over with no plugs in it (do them all at once). The gas flooded cylinders may have washed the oil off the cylinder walls and could be causing the cylinders to not have enough compression. A few squirts of oil into each cylinder and spinning it over for 15 -20 seconds solves that possible problem.

I've had really good luck just holding gas fouled plugs over a fire for a few seconds to burn off the excess fuel. I will burn the fuel off of all the plugs. I hold them with a pair of pliers with the in cylinder end over the open flame. 15 seconds with each plug will burn the gas off the plugs.

If there is any gas smell in the oil, change it and the filter.

Bring # 1 cylinder up on compression and the timing marks are correct. Reinstall the plugs. Pop the distributor cap off and put the #1 plug wire on the post the rotor is pointing at (if the #1 plug wire is in the wrong position on the cap, you need to fix that). Be sure the wires are in the correct firing position and in the correct rotation direction on both the distributor cap and on the plugs. If the carb is right, the motor should start pretty quickly. If it doesn't, look down the carb and be sure gas isn't dripping into the carb throttle area. If it is, you need to fix the carb or pressure issue.

 

On your carburetor, go back and check the choke unloader adjustment. It's frequently overlooked.

 

As a safety note, PULL the coil wire off if you are going to crank the engine over with plugs out.

A friend was having the same issues of cylinders flooding, he pulled the plugs out and cranked it over, the fuel blew out and ignited from the plug wires arcing, it was fiery mess for a while!

 

What Gene said.
I had a 215 Craigslist engine that hadn't been properly honed and broken in that I was able to resurrect with a re-hone. The cylinders were glazed so there was inadequate compression. Cranking with a little oil in every cylinder and it started and ran. The next step will be under load in the Ruby.
Since your engine has already run perhaps the walls have been washed down with the fuel as mentioned.

 

Well I think we all figured out the problem! Left the plugs out and the throttle wired open for an entire day. Oiled the cylinders a bit, and she started right up.

I think I remember pouring some gas into the carburetor bowl after some initial startup issues and maybe too much spilled down into the cylinders. The issue was then exacerbated by playing with the throttle while trying to start it. Now I get to go through the process of tuning it again, which is not a bad thing. Like I said, this is my first rodeo.

Hopefully I'm not getting ahead of myself, but thanks again gentlemen!

 

I've been there.... way to stick with it.