My 94 Z28 with about 80,000 on a LT1 engine. A few months ago the car would not start. I could smell gas but it was not turning over. It had rained quite a bit and while at the mechanic diagnostic was done and no components showed as failing and as it seemed to dry out the car started.
This morning seems to be the same issue. Again with soggy roads and again not turning over. It still has not started after sitting all day. I drove it last on Saturday with no issues tried to start this morning (Monday) and it just won't turn over. Tries to when I turn off the key feels like it almost catches but no go.
What are the most common issues with these cars or what this problem could be?
Thanks!

 

take your battery cables off and wire brush the heck outa them, do the same for the battery terminals. if it looks like a coating on them scrape with knife, a build up of carbon on either can cause a partial failed connection. ok move on to the power junction box, its the small red plastic box on the passenger side fender well, by the battery. take the wires off and wire brush the heck outa them. next to that is a ground junction, no box, may as well take them lose and clean them as well. as your doing this inspect the wire and cable ends to make sure the connection from the wire to the connector/cable end is good.

 

Engine not starting: turn the key, engine cranks over but it doesn't run.
Engine not turning over (same as cranks over, by the starter): turn the key and engine does nothing, or maybe clicks.
Some of the things you say (smelling gas, almost catches when backing off key, starts when dry) suggest the engine may be turning over, just not starting when damp out. Yet you say it isn't turning over?
Can you clarify your terminology so that suggestions you get don't have you chasing up the wrong tree.

 

Ok so to clarify the battery is not the problem. It has power and when I turn the key to start it the starter catches but the car does not start. I can smell gas under the hood so it seems as though it's not getting spark. Mechanic first suspected the fuel pump and filter. Filter was changed and now the car starts. However the water pump had recently leaked and was replaced so the distributer will be checked to make sure it's not beginning to fail. Does that make sense?

 

test fuel pressure, sometimes a failing fuel pump will work ok for a while longer with a new fuel filter. are you getting a ses light? opti failing will usually cause a ses light for a trouble code to show up. not always. ignition control/coil module can fail intermittently without showing a trouble code.

 

uh oh

waterpump was leaking, then replaced, but Optispark was not given the attention that it so often demands???

you need to understand the "4 horsemen of the LT1 apocalypse"

they are in cahoots with each other.

The optispark likes to act all innocent but he gets the other 3 to do its dirty work so he can be replaced

The waterpump likes to leak and it then leaks all over the optispark. The engineers at GM designed it specifically that way so owners of the LT1 would have something to do every few years

The more stealth contributors are the oil seals for the waterpump and optispark drive.

They like to start small and slowly and surely lead to full blown optispark failure when you are far from home and wearing nice clothes.

You'll notice a slight amount of oil drip from the front of the engine and think nothing of it.

That is what those 2 seals want you to think. During their weekly meetings, they report in on the increase of the leak and the optispark forecasts when failure will occur due to oil penetration inside it.

They have these meetings formulating their devious plan while you cruise down the road blasting the stereo, totally oblivious to what they have in store for you


There is one way to stop them cold

the moment you notice those oil drips, or the waterpump leaking, you not only replace the wp (if it's leaking) but you replace those seals as well

As you are using your large channel locks to remove them, you might actually hear very faint voices yelling that their work isn't done

Taking that precaution will mitigate what might occur in the future but take heed, once the optispark becomes aware, it will try a new tactic and work on your friends, having them convince you that it's ok to pressure wash under the hood

 

^ Ummm, ok. But still gets an....lol!!

 

love it. i have a extra opti as a threat to the group.

 

Picked up from the mechanic today and after the fuel filer was replaced it is now starting and running. They suspect the fuel pump is failing as is the distributor due to the previous water leak. The car smells heavy like gas now....runs great and I realize it will likely be short lived. Question, is the notorious Opti Spark part of the distributor?
It's sounding like the fuel pump and distributor will need to be replaced soon and it looks to be leaking oil as well. We suspect the valve cover and manifold gaskets.
Any other thoughts? Thanks!

 

opti is the distributor, intake manifold is well known to leak at the front and back where gasket maker is used to seal it.