I have an issue with my '71 LT-1 that I'm struggling to resolve.

When the car is cold it starts up no problem. If i drive it for some time (10+ minutes) the car will turn over, but will won't start. Here are some strange/interesting things I've observed when trying to get the car started.

- when warm, if i shut the car off and immediately start it back up immediately it will usually start ok
- when warm, if i shut off the car, let it sit for a few minutes, and then try to start i have a problem getting it to start.
- the car turns over like it wants to start but just doesn't start. i've replaced the battery recently so no issues there. i suspect it's not getting a spark but haven't (and don't know how) to confirm this.
- i've tried switching out the ignition coil (swapped it with my other '71)...didn't help

One last thing i find interesting when i'm struggling to get it started....if i turn the key back to the off position (because i don't want to let it turn over too long and put strain on the battery)...sometimes the act of switching into the off position will cause it to start. it feels like something is catching or causing it to start as i'm disengaging into the off position. This doesn't make sense to me, but usually when i'm successful at getting it to start that is how i do it.

Anyway, anyone have any suggestions as to what the problem may be? I've had a couple people tell me it's a problem with the carb, but someone else told me he suspects it's the ignition switch. Any advice?

Thanks,
Paul

 

If its the original ignition switch I would start there,the contacts inside do wear and then become very sensitive to adjustment.
If you want to prove it to yourself ,the next time run a temp wire from the alt hot to the pos side of the coil and then crank,if it fires up its probably the ign switch but it could be an issue with the R term of the solenoid but I doubt it.

 

thank Roger. if that's what it ends up being, is it a PITA to replace? looks like i need to take the steering column apart?

 

No , the switch is sorta on top of the column down close to your feet. It is a bit of a pain but if you've never done it. I generally do it by feel because I can't get uner the dash very well anymore. I'll see if I can find you some pictures to make things a little more clear.

 

This a later model with a dimmer switch just below the ign switch but it will be the same.
The ign switch is the silver box on top of the column. You can see the the screws that hold it on and to adjust it by sliding the switch,you can also see the rod that comes from the key that operates the switch. On the opposite side is where the 2 connectors attach,they have an order as to how they go on.

 

Thanks Roger, i appreciate it. So it sounds like i don't need to take anything apart (like removing the dash or steering column). Just have to lay under the dash doing my best impression of playing a game of twister to get at it

 

It does help to remove the 2 bolts holding the column up and allow the column to lower slightly. I like to remove some dash screws so as not to stress the dash cluster. Every little bit helps.
I wish I had some more pics to show you but I think some of my photobucket items are beginning to disappear.
Hopefully some more guys will chime in with some added info and maybe some pics.

 

Oh and make sure you get the correct switch for your column,the T&T is diff than the straight.

 

Here is another pic that shows the white connector and the black connector on the passenger side of the switch. Notice the tab(yellow arrow) from the white conn must go under the black conn,so white must be put on the switch first.

 

Thanks Roger, this is helpful. I'm going to stop by autozone and pick up a switch, and this is going to be my weekend project. I will loosen the two bolts holding up the steering column and give it a shot. For 15 bucks it's worth a shot..even if it turns out to not be the problem it's cheap (and hopefully easy enough) to give it a try. Especially where the car probably still has the original switch probably not a bad idea to replace it

 

Good Luck....... My back hurts just thinking about it.

 

So you're totally discounting Rog's advise to and change out the hard to get to switch without any testing?

You must be a glutton for punishment.

 

You just made me think about something.

Paul,is your dist stock for 71 ? The points ign has a second wire coming from the R term at the starter that should bypass the ign switch during cranking.
Maybe you a Pertronix or HEI ?
Let us know.

 

LT-1 had transitor ignition. I looked in front driver's side fender and my car still has T.I. amplifier mounted...not sure if it's working on if it's hooked up properly. I need to educate myself on how the T.I. worked, because I guess what i'm wondering is if it's not setup properly if that could be causing a problem.

I'm a bit of a novice here so please bear with me. I don't believe electronic ignition was ever added to the car. Going to go snap a photo or two.

 

hard to get a good picture but you can see what i think is the TI amp towards the bottom center of the picture. I took this picture from underneath the car near the driver side headlight.



i didn't take a picture of the starter. let me know if you need one. will probably need to lift the car to get a shot.

 

Uh oh , I missed the LT1, TI ignition changes everything.Don't run that temporary wire from the alt to the pos side of the coil.

That is the amp under the fender but I can't see if the dist is a TI dist. Is there more than 1 wire coming out of the bottom of the dist ?

 

looks like just 1 wire

 

If there is only 1 wire then the dist isn't a TI.
How many wires are on the pos term of the coil ,not including the capacitor ?
Looks like only 1

 

I've got 2 wires (black wire and the yellow shown in the picture). I don't see a capacitor


Maybe someone disconnected the T.I. leaving the amplifier and changed over to points distributor and coil?

edit: oh wait...black wire looks like it goes to the capacitor...didn't see it down there. so i guess you're right...there's one

I can't thank you enough for the help.

 

I think your right,you have points,not a terrible thing,points will work just fine.
The second black wire should go down to a small capacitor thats attached to the base of the coil.