Sbc getting gas/spark but wont run.

A year ago I rebuilt a 350 sbc hei dizzy. I put a thumper comp cam in it, comp double roller timing chain/sprockets etc.

A few weeks ago I fried my module in the distributor, I had an extra so I swapped it in BUT I put bearing grease on the bottom side of the module...everything worked good for a few weeks (its my DD).

Until this past friday I was comming home it died I coasted to a stop and got a ride home (only like a mile from home by now).

Figured it was the module so I got a new one, still nothing.

I get fire, and im getting gas. But it wont run/hit.

HELPPP

Thanks

 

Small hole burnt in center of rotary button?

 

rotory button, the rotor I assume?

I had it out multiple times didnt notice a hole...it would have to be super small.

Im at the end of my rope, Gfs dad suggested maybe it jumped time?

 

All engines need the same thing to run
1-Air
2-Fuel
3-Compression
4-Properly timed hot spark
"fire" When checking spark at the plug remember "red is dead, blue will do, white is all right, and fat is where it's at.

 

gotta get air (had breather off temporarily)

getting fuel

shoudl be getting compression (pretty much new motor)

properly timed spark?,,

Hmm i'll have to try to remember the saying

whats fat>

 

Did you check the pickup coil in the dist.Ihave seen those work good enough to produce a weak static spark when cranking put not enough to fire engine. If you havent checked you may also have fouled plugs from cranking and pumping fuel with no fire. I have also seen bad module damage the coil

 

No, im sorta new to distributors (i havent had to mess with them yet) whats the pickup coil look like exactly (sorry).

I have 2 coils I'll swap em tomorow and see what happens i'll write down pickup coil and see if haynes manaul has a testing method

thanks keep it comming guys

 

If it's the pick-up coil you might get away with unhooking your vacuum advance hose to get it to fire. When the vacuum advance rotates the pick-up coil it will cause it not to fire. You'll need a Ohm meter to test it stationary and then while the vacuum is applied and the plate moves.

 

Joes50 is right about unhooking the vacumm line. The pickup coil is located in the bottom of the dist. Its has two wires that plug into the ign module.sometime you dont even have to test as youll see one of the wire broke or damaged

 

Fat is getting a good healthy amount of fuel, lean is a salad bar at a steak house

 

I'll go look in my book and try to start it with no vac adv

 

Didnt start with vac adv unhooked

I tested the pickup coil i believe its OK

 

Did you look for the small burnt black hole in the center of the rotary button?
Ive had that happen to me a couple of times years ago.

Is your rotar pointing towards #1 plug wire position with the #1 cylinder up on tdc.
(check the actual piston threw the spark plug hole on the front driver side to make sure its up on top dead center) and/or
with the timing mark also up on tdc on the harmonic balancer to make sure its on compression stroke.

 

vacuum leak? make sure all the holes in the carb and manifold are plugged and your hoses aren't split.

what do the plugs look like? wet and black? or dry and grey? whats the gap

Maybe ignition timing. Try turning the distributor while you crank to advance or retard the spark and see if anything changes.

 

put a vacuam gauge on it , crank it , look for cranking vac. if no vac or no needle movement at all , check air --- in , out , exhaust plugged?

 

If you have a good spark why mess with the distributor? That must be working right.

I'd be concerned about timing. I'd check the rotor position after the thumb in the spark plug hole. I've never had it happen on a Chevy but I've had a couple of different engines jump time while driving.

Ya got gas compression and spark the only thing left is timing as I see it.

 

Had a hole burnt under the center of the rotor button swapped that out still nothing

Now im getting NO SPARK at all?

Here is my thread on another forum

http://67-72chevytrucks.com/vboard/showthread.php?t=477114

 

I forgot to plugt he module back in, it was a burnt (less than 1 year old msd rotor)

Gonna try to get some $ back on that or something!

 

I went through all that earler this year. Turned out to be the pin that holds the dizzy gear had sheared. Wasn't turning.

 

Soooooooo......we gotta guess, or what? Is it runnin', or NOT? DD

 

It runs, thanks alot guys

Turned out my less than a year old MSD rotor button burnt a hole in it and wasnt putting all the spark to the wires, alot was grounding. The module was fine but its gotta new one in it now lol

Im running vortec heads on my 355 flat tops 9-1 compression pickup truck. I have some champion sparkplugs. I wana put new plugs in it, what should I use?

 

I had the same problem as you. I found out that if you are running a MSD you need a special bushing in the cap under the coil where that round rubber disc is The bushing has a spring on it. I think they call it a low resister bushing. If you don't use one it (the bushing) will fail on you.

 

I worked with some guys who liked to play tricks on each other and one pulled a couple of plug wires off the others 74 chevy pickup. He couldn't get it started to go home. Burned a hole through the rotor. The original 60,000 volt HEIs would burn a rotor if the plug gap (.060) got too wide or the wire resistance got high.

 

Ck the rotor and cap for carbon tracking. It could be several things but this is how you learn to troubleshoot.

 

what does carbon tracking look like? (it seemed to have some red dust on the coil) and black maybe on the insdie of the cap?

 

Autolite plugs will do the job, Champions have gotten really cheap, had alot of bad ones out of the box.

 

arbon tracking will be a black powdery dust, will actually form a line around cracks, but if enough of it builds up between 2 contacts, it will actually carry some of your spark away to split it between the 2 contacts