If it starts cold, it could just be the starter brushes are worn out.
remove the starter, get an electrical guy to undercut the armature, and reassemble.
$15 at best.
I took mine apart, and the commutator mica had held up the brushes when hot since the copper commutator bars wore down. no electrical flow when that happens.

 

It only happens hot really. If the car sits overnight, in the morning it starts no problem. But if I got to a car show for example, which is about 45 minutes away, then stay for about 2 hours, it will take a few tries and some waiting for it to fire up.

Also, i found out that my car has a short somewhere. If the engine is on and i lean on the plenum and the touch something grounded i get a pretty good shock. Could this be adding to the starting problem?

 

WTF?? There should be no reason to get a shock from any metal part of the engine. The battery ground cable is attached to the block and any metal engine component is bolted to the block.

Are you touching a spark plug wire at the same time as the plenum? Or at least getting very close to one? Plug wires carry high voltage and you could be feeling some sort of stray voltage coming off a wire.

As far as the starter, it sounds like you could have a problem with the clutch safety switch, a bad solenoid, or possibly a bad or loose connection in the positive battery cable. Is the positive cable tight at the battery? Another possibility is a bad ignition switch or even the resistor in the key.

If you got a jump start to work, check the battery voltage at the terminals. Also check the condition of the cables where they attach to the battery. Anything loose or covered in corrosion will not allow good contact, resulting in less current to pass.

Just because the battery is new doesn't mean it isn't partially discharged or has a bad cell. A fully charged battery will show a voltage of 12.8v or so. Have the battery charged and then load tested.

If you are going to install headers at some point, a "mini' starter" isn't really necessary. The OEM stater will work but it will have to come out for the header install. After you place the header up in place, then the stock starter can go back in. Once the header is bolted up, the stock starter will not come out without removing the header.

A mini starter solves that install problem but you will need to either extend the positive cable or install one that is about 4-6" longer. Mini starters are a gear-reduction type and typically take less power to run than an OEM unit.

 

Ya the shock doesnt give me a comfy foxy feeling either. As for the jump start, it worked the first time but thats it. Now when I try to jump the car it still wont start. Im in the process of setting up something that will bypass the clutch safety switch so I can test that theory out.

 

Just jumper the two wires going into the switch at the top of clutch pedal to bypass it but doubt that is heat related

 

Shock from the plenum? Now thats interesting. My '85 has an aluminum dizzy cover (not the cap) attached to the plenum so that may be shorting some how across the distributor. If the electricity is shorting here before it reaches the plugs I would think this would cause hard start problems. Just to see, take off your dizzy cover and see if it solves either problem. I am really curious now!

 

Im a kid so take my advice with a grain of salt.

I dont think its the starter. I had the EXACT same symptoms on my 85 auto. I kept thinking damn solenoid is taking a **** but nope. My IGNITION CUTOFF was faulty.

This is where I would start. Took 15 min to fix and havent had a problem that I was having EVERYDAY. It would let me start once but once I shut it off and let it sit for more than 3-5 min it would trip the system and not crank.

Just the words of a dumb kid...

If you decide this route PM me and I can send you a through write up

 

I'm PMing you 383.

 

Dont sell yourself short, if you can help someone your input is as valuable as anyone elses.

Bucs, if this solves your problem, keep us posted.

Good luck!

 

I tried his method. It did work but it might have been coincidence. After I jumped the cutoff and got it to start, I took the jump off and it still started fine even with the jump off. Coincidence? or does jumping that cutoff once somehow disable it?

 

The jump disables it permanently. I did it and left it in to make sure it wont happen again.

Like before your car would only do it once it got hot so try it all after a drive turn it off leave it for 2 or 3 min then try to start it. If the system trips and cant start just leave the jump.

No offense to anyone on here but this has not been my corvette forum of preference for quite some time due to bashing and overpowering mods so i try to avoid it.

 

Today I was able to try 383's method again and......IT WORKED!!!! I drove the car around and got it nice and hot, stopped at my house and parked it like I was in the auto parts store for a bit. Tried to start and nothing, used 383's jumping method and it fired right up, took the jump off, woulndt start, jumped it again and it fired up fine again. So I think this is the culprit! Heres a few pictures of what I did for everyone to see:

This is what it looked like all together.




This is what I did to jump the purple wire and the second inward thick green wire.




Finally, this is the box that goes to the connector I jumped. I assume this is the correct box considering the jump worked but who knows. Also, what else does this box control? Would it be bad to leave it unplugged and jumped?

 

That box is a relay, the Theft Deterrent Starter Interrupt Relay to be exact. On the '84 and '85, this relay is wired as an interrupt and on the later VATS equipped cars it is wired as an enable. The narrow green wire to the left of the purple in your picture comes from the Theft Deterrent Control Module. If it senses an alarm condition, it will sound the horns and energize this relay to disable starter. Won't hurt to leave it jumped as that is the way it is wired through the NC relay contacts.

 

Glad I could help

 

Bucs, did it act like the battery was weak? My 85 is doing the same thing. Real draggy and wont start while hot. Wait 30 minutes and fires right up;. Was thinking it was the selanoid.

 

follow what he posted up top. Sounds like you are suffering from what we both had.
Anti theft system is wacked

 

Ok. Tonight after work I drove around and got the car all warmed up, got home and locked it all up and whatnot. Then I went back in a few minutes and found that the car wouldnt start, perfect time to try this method again....and IT WORKED! This time however, after I got the car to start that way I turned it off and put everything back the way it is supposed to be without a jumper and the car started fine again....Im not really sure what that means?

 

Update....Ive tried this jump a few times and sometimes it works and sometimes it doesnt. So, I think I still might need a starter.

Will a starter like this work? http://www.summitracing.com/parts/SUM-829100/

Im not looking to spend a fortune but I want something thats better than a stock one. When I replace it I plan to fab up a heat sheild of some sort and have also read about heat wrap for starters, any opinions on that?

 

It means that the relay contacts are not reliable, sometimes they make good connection, sometimes they don't. You might try installing a new relay!

 

Where can I get one? I went to my local auto store and asked for a starter interrupt relay and the guy looked at me like I had ten heads.