Please rescue me!

[Chris Sanchez]

Hey gang,
Well I did it to myself!:eyerole I got impatient to get to work on my 81 (needed the cam replaced) so instead of waiting to borrow my friends digital camera I just shredded right into it trusting my memory. You can guess the result. I'm trying to put it all back together now after three weeks and some of the vacuum routing, accessory brackets etc. are driving me nuts. Of course I have the Chevy fact assm. manual and the 81 corvette shop manual so I thought I would be alright. I should have checked first! Anyway, if any of you good folks have pictures of your engine compartments with all of the accessories and vacuum hoses in place (minus air cleaner) I will gladly give blood if you'll post them. This model has A/C, Cruise, P/S and an A.I.R. pump.
Thanks for the help!
Chris

 

[trent81]

Chris,

Check on the L81vetteregistryforum. Someone on there can probably help you.

Trent

 

[mike weyman]

any good?

 

[brusso]

Hey Mike, where is the shroud?

 

[Chris Sanchez]

Thanks Mike,

Helps a little. I really appreciate the picture post! I THINK I have the vacuum stuff sorted out but I just tried to start the car and I have no spark. The kid who had the car before me had a MSD installed and I'm trying to run it with the stock ignition. What I need to know at the moment is, What color are the two wires that go into the H.E.I. at the BAT and TACH positions. (Three wire harness from the distributor just plugs into the back space, I think) Any clue guys?
Thanks again for the input. It's nice to feel like you aren't alone!
Chris

 

[Flared69]

would it be similar/the same to my dad's '80?

I'll take pics if you want.

 

[bossvette]

Thanks Mike,

Helps a little. I really appreciate the picture post! I THINK I have the vacuum stuff sorted out but I just tried to start the car and I have no spark. The kid who had the car before me had a MSD installed and I'm trying to run it with the stock ignition. What I need to know at the moment is, What color are the two wires that go into the H.E.I. at the BAT and TACH positions. (Three wire harness from the distributor just plugs into the back space, I think) Any clue guys?
Thanks again for the input. It's nice to feel like you aren't alone!
Chris

BAT is a 10 gage red wire (big)
Tach is a brown small wire (20g)

 

[GerryLP]

Thanks Mike,

Helps a little. I really appreciate the picture post! I THINK I have the vacuum stuff sorted out but I just tried to start the car and I have no spark. The kid who had the car before me had a MSD installed and I'm trying to run it with the stock ignition. What I need to know at the moment is, What color are the two wires that go into the H.E.I. at the BAT and TACH positions. (Three wire harness from the distributor just plugs into the back space, I think) Any clue guys?
Thanks again for the input. It's nice to feel like you aren't alone!
Chris

Chris,

The BAT wire color is a faded pink or beige in my car. This is a heavy wire -10 wire gauge and the connector is white. The TACH wire has the connector in brown color and beige wire. It's the one that is hard-wired to the filter on the right side of the engine near the distributor. This is a 12-gauge wire.

I don't think that the car will run if you leave the MSD box's wires hooked-up.

 

[Chris Sanchez]

Thanks for the info folks! i found the faded pink wire that goes to the BAT side and I'm beginning to suspect that I'm going to have to completely disconnect the MSD for the car to work. What is confusing is that I thought I had done that before I took the top end apart and the car was running (although poorly with the bad cam). It's entirely possible though that the reality is that part of the MSD was still working at that point and I just didn't realize it. One more question though, I thought that as long as the BAt wire was hooked up properly there should be a spark. Regardless whether the TACH wire was connected or not. Is this correct? I now have the correct BAT wire in place and the clip that goes behind it and I still have no spark. Could the ground in the clip be bad?? I feel like I'm overlooking something simple( read...stupid). Anyway thanks for the help gang. Oh yeah and the pictures I need are the routing for the tan colored vacuum fitting hoses off of the Thermostat housing and the mounting bracket pieces for the A/C compressor. I have two round crooked rods that I know somehow are a part of the mount for the a/c but I'll be jiggered if I can figure out how I took'em apart

Thanks again, I don't know what I'd do without CAC!
Chris

 

[mike weyman]

chris, never noticed the shroud before,i downloaded the pic on the b.j. auction pages.(supposed to be all original)I needed vaccum routing so i downloaded it. bet it runs hot.mike

 

[wishuwerehere82]

The contacts that go through the distributor cap that clip onto the ignition leads(larger connector behind the Batt and Tach connectors) can push up into the distributor cap when you push the connector on. Pull the coil cover off the cap and make sure they are engaged with the distributor connector(push them back down).That is something I have seen more than a few times.

 

[GerryLP]

Thanks for the info folks! i found the faded pink wire that goes to the BAT side and I'm beginning to suspect that I'm going to have to completely disconnect the MSD for the car to work. What is confusing is that I thought I had done that before I took the top end apart and the car was running (although poorly with the bad cam). It's entirely possible though that the reality is that part of the MSD was still working at that point and I just didn't realize it. One more question though, I thought that as long as the BAt wire was hooked up properly there should be a spark. Regardless whether the TACH wire was connected or not. Is this correct? I now have the correct BAT wire in place and the clip that goes behind it and I still have no spark. Could the ground in the clip be bad?? I feel like I'm overlooking something simple( read...stupid). Anyway thanks for the help gang. Oh yeah and the pictures I need are the routing for the tan colored vacuum fitting hoses off of the Thermostat housing and the mounting bracket pieces for the A/C compressor. I have two round crooked rods that I know somehow are a part of the mount for the a/c but I'll be jiggered if I can figure out how I took'em apart

Thanks again, I don't know what I'd do without CAC!
Chris

Chris,

You'll see (albeit, the instructions do not come-out and "tell" you that the BAT cable is not used with the MSD hooked-up) that the BAT cable is not used in its stock configuration, for the MSD box already gets its juice straight from the battery. In this link, you'll find the installation instructions for the MSD 6 Series boxes: http://www.msdignition.com/pdf/6series.pdf

It took me a couple of hours to figure-out, and if you look under "hi rpm miss" troubleshooting in page 9 it states "Inspect the Primary Coil Wire connections. Because the MSD is a Capacitive Discharge ignition and it receives a direct 12 volt source from the battery, there will not be any voltage at the Coil Positive (+) terminal even with the key turned On. During cranking or while the engine is running, very high voltage will be present and no test equipment should beconnected."

So when you connect the BAT cable, then it'll turn over, but it won't start. You'll have to disconnect the MSD box. Also look at the 7-pin HEI installation diagram in page 16 and 17 for more clues. I had replaced my distributor with a 4-pin type in order to adjust the advance timing manually. You can remove the distributor shield, wire retainer, and the coil cover to inspect the coil terminals. You could have a broken connection there. I am not usre, but according to the diagrams, the 7-pin distributor gets to keep the module inside, but if you see a violet and a green wire harness coming from the distributor base, then it was removed.

p.s. The BAT cable is a good source for the required switched-12 volt source for the MSD box.