GM small block mechanic help

[JeepHammer]

The most common,
Using the timing tab to find TDC and getting TDC of exhaust,
Not backing the rotor rotation up and getting firing order one terminal advanced,
Not getting ignition power when cranking, simply add a wire from starter solenoid 'I' (ignition) terminal to distributor + or Bat terminal,
Its usually rookie mistakes, brain farts that cause these issues.

 

[churchmouse]

The most common,
Using the timing tab to find TDC and getting TDC of exhaust,
Not backing the rotor rotation up and getting firing order one terminal advanced,
Not getting ignition power when cranking, simply add a wire from starter solenoid 'I' (ignition) terminal to distributor + or Bat terminal,
Its usually rookie mistakes, brain farts that cause these issues.

Pull #1 plug and bump it over with your finger in the spark plug hole until it burps. If you went pqst TDC it will push finger out of the hole. If not it will just burp. Adjust timing mark on the dampener to TDC accordingly.
If you are solo a piece of paper towel in the hole will work if you just bump it over.

A good mechanics under hood jump button solves the dilemma of needing 2 people for this.

 

[JeepHammer]

The old cork trick.
Gently push a cork in the #1 hole, bump until it pops.
I saw a guy use a paintball of all things one time...

If you crank by hand GENTLY you can use a thread in piston stop.
Starter & piston stop is a disaster waiting to happen.

 

[churchmouse]

The old cork trick.
Gently push a cork in the #1 hole, bump until it pops.
I saw a guy use a paintball of all things one time...

If you crank by hand GENTLY you can use a thread in piston stop.
Starter & piston stop is a disaster waiting to happen.

My initial set up is the engine is set to TDC on the stand. No plugs and hand turn #1 to tdc and check the balancer/degree indicator for correct. Prime the oil pump with the tool I made from an old HEI distributor and 1/2" drill motor. I have an analog gauge for this. Set the distributor and run the plug wires. A simple sharpie mark makes it pretty simple to put the dist. back in once the engine is set.

Does anybody do the static spark setup...???
Fill the float bowls with fuel. Especially with a mechanical pump. We went to electric pumps long ago.

If the engine is properly prepped it is usually easy peasy to fire it off.
I always try and set the engine/trans as a unit so having everything in line when the engine is set in is not a huge thing.

 

[boogieman]

My initial set up is the engine is set to TDC on the stand. No plugs and hand turn #1 to tdc and check the balancer/degree indicator for correct. Prime the oil pump with the tool I made from an old HEI distributor and 1/2" drill motor. I have an analog gauge for this. Set the distributor and run the plug wires. A simple sharpie mark makes it pretty simple to put the dist. back in once the engine is set.

Does anybody do the static spark setup...???
Fill the float bowls with fuel. Especially with a mechanical pump. We went to electric pumps long ago.

If the engine is properly prepped it is usually easy peasy to fire it off.
I always try and set the engine/trans as a unit so having everything in line when the engine is set in is not a huge thing.

I set TDC on the stand without plugs or the valve covers on. I primed the oil pump with a drill. I didn't put the wires on but did mark the rotor location for #1 with a sharpie on the outside of the cap. We left the trans in the truck this time. I did switch to a manual fuel pump and disconnected the electric pump in the fuel tank. Everything I researched said to do that because the electric for the TBI puts out to much pressure for the Edelbrock carbs. The truck is sitting outside so with this wonderful weather we had this weekend I did not get into it.

 

[churchmouse]

I set TDC on the stand without plugs or the valve covers on. I primed the oil pump with a drill. I didn't put the wires on but did mark the rotor location for #1 with a sharpie on the outside of the cap. We left the trans in the truck this time. I did switch to a manual fuel pump and disconnected the electric pump in the fuel tank. Everything I researched said to do that because the electric for the TBI puts out to much pressure for the Edelbrock carbs. The truck is sitting outside so with this wonderful weather we had this weekend I did not get into it.

There are regulators available to use for this. If not mistaken the system has a return line. Holly makes a simple bypass regulator that will work very well here if you use the return option on it.
Spinning the engine over to put the flex plate bolts in for the convertor will confuse some folks and they loose TDC in this process. Not saying you did this just a general statement for anyone that might need this info.

lots of great info shared in this thread.

 

[MRockwell]

Have you tried turning it off, then turning it back on again?

OK, seriously...I have an 84 5.0, with the coil on top the distributor. Several years back, I went to start it up and nothing happened. Went and bought a new coil and BAM! started right up.
Granted, I am not familiar with the Mallory hei stuff, mine was all stock.

I mean, hey, my suggestion has to be one step above unCOILed rice.LOL

 

[Dead Duck]

Is the engine well lubricated?

 

[DoggyDaddy]

Have you tried turning it off, then turning it back on again?

OK, seriously...I have an 84 5.0, with the coil on top the distributor. Several years back, I went to start it up and nothing happened. Went and bought a new coil and BAM! started right up.
Granted, I am not familiar with the Mallory hei stuff, mine was all stock.

I mean, hey, my suggestion has to be one step above unCOILed rice.LOL

I think in this case you want to make sure you have an un-riced coil.

 

[JeepHammer]

It's pretty easy to set initial timing, once the distributor drops into place with rotor pointing at #1 plug wire,
Simply turn crank back to the VERIFIED hash mark on the balancer to the advance you want, then rotate distributor until reluctor in the distributor lines up directly. You should be within 2 degrees of what you wanted when it starts.

The reluctor (toothed 'wheel') in the distributor shaft won't fire the ignition until it passes center of the points hall trigger.
Dead center is slightly before firing, and we are talking microseconds when the crank starts moving.

In the old days, we used a battery powered continuity tester across breaker points to tell us exactly when points opened, and with the crank set at 6* or 8* before TDC, it was little problem to set the distributor to fire at that point.

As the reluctor rotates through the hall trigger field, it produces a positive, or negative pulse (depending on how the hall is wound).
When the reluctor passes center (zero point) the polarity flips, if it started positive, it flips to negative, if it was negative, it flips to positive.
The flip is the trigger signal.

You can rotate the distributor body slightly, 6 or 8 crank degrees is 3 or 4 distributor degrees, the crank has to turn twice for one rotation of the distributor shaft, so it doesn't take much to line up the reluctor with the hall trigger.

Different manufacturers use different sides of the pulse (positive or negative) to trigger, this shouldn't be an issue with an HEI clone since it's already set up correctly for the module.

 

[ATOMonkey]

A timing light is great to let you know if you have spark and if it has a dwell knob on the back, you can even see how far off you are when cracking.

I have been guilty of dropping in a distributor one gear tooth off before.

 

[JeepHammer]

That's an advance knob, but we get the idea.

Dwell angle hasn't been a thing since we stopped using breaker points, but a dwell meter on an electronic ignition coil will help diagnose bad hall triggers and modules on the way out, but not fully failed yet.

On the other hand, trying to draw fuel through the in-tank pump isn't a good idea and the only other ports are return line & vent, neither reaches fuel in the tank.