NEED some WAGS( wild as

[A1971Blazer]

s guesses)......
'72 350 with HEI in my K/5......not a DD at all....so I start it up frequently and drive it when I can....
Last Thursday..started up, warmed up...shut it off....

Friday afternoon....went to start and drive....two or three, what sounds like backfires, and the starter hung up in the flywheel.....got that fixed.... tried to start up.....

same thing a few backfire sounding noise...but no start...

I'm thinking....best case.....ignition module?
worst case....jumped time.....tomorrow I will pull the cap and check for that

I have no history of this motor...except that it's been running like a champ
until now....

[Warrens69GMC]

loose rotor in dizzy?
Wires arcing together?

[truckster]

It doesn't sound like a module to me, but it could be that it jumped time. Possibly also arcing inside the cap - I've had that happen before.

[68gmsee]

As above, I'd start with ignition. HEI cap and rotor first then check timing with #1 piston at TDC on compression stroke and timing mark lined up with timing tab. Then cross firing or arcing of spark plug wires. If that's all good it's really a "WAG" until you do a compression check on all cylinders.

If all checks above are good and if you have a quadrajet check for leaking well plugs. There will be a pooling of fuel in the intake that can cause backfiring and it's a known problem.

[A1971Blazer]

I'm happy to report....the noise that sounded like it was backfiring....
as it turns out...the culprit is the starter....

[68gmsee]

Since we assumed it was backfiring, I guess you did get some "wags".

Glad you found the problem, though. Do you know what exactly the problem is or are you replacing the starter/solenoid complete? Might help someone else in future diagnosis.

[A1971Blazer]

Originally Posted by 68gmsee

Since we assumed it was backfiring, I guess you did get some "wags".

Glad you found the problem, though. Do you know what exactly the problem is or are you replacing the starter/solenoid complete? Might help someone else in future diagnosis.

From inside, it first sounded like a backfire...I had already pulled the inspection cover off the transmission, looking for loose torque converter bolts and possible mechanical contact somewhere......that's when I first discovered the starter was hung up....I had also pulled the valve covers looking for a dropped valve too..

I got it loose and then I got my buddy to crank it over while I was underneath that's when I figured out it was the starter making the noise.....it's looks to be kicking away from the flex plate....

It will start up now..... so I'm gonna move it into the shop and put it on the lift.....(I hate laying on the floor working on a starter) so I can do some closer inspection...it's likely that it isn't shimmed correctly or the starter head is weak or cracked.

I went ahead and ordered a new starter today, along with new bolts and some shims...also plan on putting a rear brace/bracket on it as well....

and thanks for the WAGs...

[mattfranklin]

Originally Posted by A1971Blazer

I'm happy to report....the noise that sounded like it was backfiring....
as it turns out...the culprit is the starter....

Let me guess it was the starter. :-)

[A1971Blazer]

Originally Posted by mattfranklin

Let me guess it was the starter. :-)

Hey.....that could be it...

On an unrelated topic I see in your signature "1970 LT-1"
My buddy's Dad used to own a Chevrolet dealership years ago...we would go in at night and add our hot rod parts to the parts man's order...back then.....a brand new, complete LT-1 short block was $325.00 dealer cost...we bought a few....wish I still had them....!