Another "won't crank" issue

[LanceBrad]

Similar to the other recent threads about this, but enough different that I figure it deserves it's own thread. 1979 Grand Prix, 301 2bbl, all original, transmission rebuilt about 800 miles ago and brought in for the transmission follow-up about 50 or so miles ago.

Scenario:
Very hot day in Florida I get off work and go to start the car after sitting in the parking lot all day. 1st crank - it sounds rough and is a little weak. Not normal, but not necessarily "bad", and doesn't start. Not surprising as it's been all day and usually starts on the 2nd try anyway. 2nd crank, it has the same sound, and is still slightly weak, but starts right up as I was expecting. I left the lights on a couple weeks ago and had to get a jump, and one day last week it had a slow crank, so I was thinking on the way home, I probably need a new alternator (and likely battery). I drove home at highway speeds for about 10 minutes - it ran just fine the entire way, no issue at any stoplights, no issue at 70 mph, no issue at 40 mph. Ran exactly normal the entire drive home. When I got there, I turned it off and tried to start it again. Same thing as when I was at work. Slightly slow crank with a rough sound, but started. So I pull it into the garage and throw the charger on the battery to charge overnight. got up this morning and see the charger showing 100%. Hop in ready to go to work and it doesn't even crank. No clicking, no weak turn, no sound at all that I can hear with the window down. Headlights work, radio is on, horn works, interior lights are very bright. Nothing when I turn the key.

What I've tried so far:
I hooked up a small, cheap jump pack (display showed 85% charge on the pack itself) and it didn't change anything. Shifted it into Neutral and tried to start it, same thing, no sound, no crank, no anything. Shifted back to Park, let my foot off the brake, it rolled backwards about an inch, and I tried again. Same thing, no sound, no crank, no anything. So I pulled the battery, everything looks good, clean, etc. There are a couple very small spots on the positive contact point on the cable that have the tiniest bit of corrosion - was the red bolt the tiniest bit loose??? Could have been now that I look back on it, but I don't think so and it's been starting/running fine except the couple times I recently needed a jump after leaving something on. So I bring the battery for a load test and it's fully charged and cranking at the right amps (actually ever so slightly higher than rated).

Planned actions:
When I get home tonight I am planning on thoroughly cleaning the contacts (even though they look clean already), and ensure they are tight and give it another shot. I'm hopeful, but expecting no change. Tomorrow the plan is to visually check all the cables into and out of the starter, maybe give it a tap-tap with a hammer and try it again. If that doesn't work, I have a solenoid bypass switch that I'll hook up to see if it starts with that. I'm really hoping it will as I believe it is likely a bad starter and/or solenoid. However, I'm a little concerned about the "rough" sounding crank the last 3 times it did actually crank and I don't want to do any damage to the engine (if I haven't already). Would a bad starter and/or solenoid cause it to not do anything at all when the key is turned? I thought I would hear at least something, but no.

Questions:
Should I do anything else as a precaution before trying to start it again?
What else can I check if none of the above work?

Thanks in advance for any advice/info!!!

 

[383_StealthRam]

Sounds like you've ruled out battery, but definitely check n tighten all battery cable connections, and grounds.

Everything you've described from a symptoms perspective tends to point to failing electro-mechanical starter and/or solenoid issues.

The only thing you mentioned is that when it does nothing, no click..no crank..no sound; you need to confirm the wire from IGN switch to solenoid is working properly. Test light at purple wire at starter solenoid while attempting to crank is what you need to do. My guess is that it is ok, and your starter was starting to die when it was intermittently working and finally did.

The noise could have been the drive gear, or the starter internally. Check to make sure all the teeth on the flex plate ring gear are intact. If the starter ever engage and disengaged with the engine running and chipped a few teeth that would surely make some noise when cranking thereafter.

How old is the starter, if you replaced it in the past was it new, or rebuild/reman?

Hope this helps!

 

[383_StealthRam]

Make sure the starter itself isn't loose to the block mounting. The two main bolts that hold it on.

If it has a rear bracket to the block, check that as well.

Lastly, not common but I have seen cases where the solenoid screws that attach it to the starter come loose, or even fall out.

I think a new starter is in your future most likely.

 

[LanceBrad]

Sounds like you've ruled out battery, but definitely check n tighten all battery cable connections, and grounds.

Everything you've described from a symptoms perspective tends to point to failing electro-mechanical starter and/or solenoid issues.

The only thing you mentioned is that when it does nothing, no click..no crank..no sound; you need to confirm the wire from IGN switch to solenoid is working properly. Test light at purple wire at starter solenoid while attempting to crank is what you need to do. My guess is that it is ok, and your starter was starting to die when it was intermittently working and finally did.

The noise could have been the drive gear, or the starter internally. Check to make sure all the teeth on the flex plate ring gear are intact. If the starter ever engage and disengaged with the engine running and chipped a few teeth that would surely make some noise when cranking thereafter.

How old is the starter, if you replaced it in the past was it new, or rebuild/reman?

Hope this helps!

Thanks for the information! That makes me feel better for sure.
I've never replaced it (or anything else on the car other than the suspension & spark plugs) as I just bought it in September. I have a feeling it is original (only 60,000 miles on the car), but have no way of knowing for sure.

 

[LanceBrad]

...I think a new starter is in your future most likely.

I almost preemptively ordered one last night. Now I just need to make sure I get the right one (quality & fit). There's a lot of choices out there that say they are an exact fit.
Thanks again.

 

[383_StealthRam]

From what I can tell they seem to list 2Bbl and 4Bbl starters, not sure what difference is? If it's just STD vs HI Torque like most GM starters of that era, either may work fine and bolt right up.

I don't know enough about Pontiac 301's if there's some other issue, hopefully another forum member has that answer for you.

 

[LanceBrad]

From what I can tell they seem to list 2Bbl and 4Bbl starters, not sure what difference is? If it's just STD vs HI Torque like most GM starters of that era, either may work fine and bolt right up.

I don't know enough about Pontiac 301's if there's some other issue, hopefully another forum member has that answer for you.

Well, I just ordered one from Napa that's "guaranteed to fit", so I guess I'll find out tomorrow!

 

[LanceBrad]

Well, I just ordered one from Napa that's "guaranteed to fit", so I guess I'll find out tomorrow!

*ALERT*
The Napa part that was guaranteed to fit my all original (including the original starter) 1979 Grand Prix LJ with the 301 2bbl *DID NOT FIT*. It was a mirror image of the original. My mechanic said (yes, sometimes I use a mechanic!) that it really wasn't my fault for buying the wrong one, because every reference he was able to find showed the incorrect part. Crazily enough, the alternator/starter shop he took it to to have it rebuilt had an old AC/Delco - the correct one - ON THE SHELF!!! (covered in dust I can only assume).
So, the real update is she's up and running again, the starter did the trick, and beware when buying a starter for that engine. You may end up with the wrong one also!

 

[86 Salon]

From what I can tell they seem to list 2Bbl and 4Bbl starters, not sure what difference is? If it's just STD vs HI Torque like most GM starters of that era, either may work fine and bolt right up.

I don't know enough about Pontiac 301's if there's some other issue, hopefully another forum member has that answer for you.

My guess would be that in 79, your car could have come with a 301 Pontiac with a 2v carburetor or a Chevy 305 with a 4v carburetor. They're both 5 liter engines. The parts store should have asked you the vin. That would have told them what engine the car came with.

 

[383_StealthRam]

My guess would be that in 79, your car could have come with a 301 Pontiac with a 2v carburetor or a Chevy 305 with a 4v carburetor. They're both 5 liter engines. The parts store should have asked you the vin. That would have told them what engine the car came with.

Sounds like that explains the starter difference as LanceBrad found out. Pontiac and Chevy engines have starters on the opposite sides of the engine, like Olds vs Chevy (Buick too?, not sure) 🤔