D981 Starter Solenoid

[Richard M.]

Re: D981 Starter Solenoid

Rich-------


On all 1969+ C3 the switch is "buried" in the lower column. Very hard to access. This is by design as it's supposed to be a "theft prevention" measure.

Okay thanks for the clarification Joe. I knew the very late C3's had it in the buried area as I had to access the switch on a '77 a few years ago while working a directional switch electrical issue on a tele column. It certainly was not fun. That's when I also learned of the differences in the switch mechanicals and the lever mechanism differences. IIRC, the assemblies were different within the same year with or without cruise control. The angles of the levers require different mechanisms inside the column housing due to their angle properties.

I must say that working under the dashes on C1's and even C2's is by far much easier than C3's.

Rich

[Joe L.]

Re: D981 Starter Solenoid

Okay thanks for the clarification Joe. I knew the very late C3's had it in the buried area as I had to access the switch on a '77 a few years ago while working a directional switch electrical issue on a tele column. It certainly was not fun. That's when I also learned of the differences in the switch mechanicals and the lever mechanism differences. IIRC, the assemblies were different within the same year with or without cruise control. The angles of the levers require different mechanisms inside the column housing due to their angle properties.

I must say that working under the dashes on C1's and even C2's is by far much easier than C3's.

Rich

Rich------


The 1969-82 Corvette ignition switches were the same although they were different for standard column versus tilt-tele applications.

[Mark E.]

Re: D981 Starter Solenoid

...I was having constant problems starting it and when it did start it ran horribly, it didn't have any power, and it pinged constantly.

Ken-

Fascinating thread. What was the cause of the engine running horribly, with no power and pinging?

When the mechanic installed it and tried starting it a few times, the starter would keep running, even with the key in the off position. He uninstalled it and tested it on the bench, and had the same problem.

And regarding the starting issue: If the problem with the starter not turning off can be re-created on the bench, wouldn't that isolate the problem to the starter or solenoid?

As a check, have you re-installed the original (incorrect but working) starter? If the problem stops, that confirms the problem is the starter or solenoid.

[Domenic T.]

Re: D981 Starter Solenoid

Mark,
I was thinking the same. Also, I rebuilt all my old solenoids and as I remember there is a possible connection gone bad that could keep the solenoid powered after getting activated. Another thing I once had a problem with was the correct spring. One was much shorter than the other and was sluggish.

Dom

[Kenneth H.]

Re: D981 Starter Solenoid

Mark, there seemed to be a multitude of issues with the poor performance. Mainly, the problem was that initially I could only find mechanics who "claimed" to be experts with old engines, but really weren't. As they tried to fix the problem, they apparently made it worse. I final found a good mechanic (NCRS member and longtime Chevy mechanic who actually raced an LT1 back in the 70's) who spent the time to figure it all out, but along the way found a few other non-performance issues as well.

When he originally looked at the LT1 and did some preliminary analysis he found that the engine would only start when the timing was set around 42 degrees BTD center. If he tried to set the timing to it's normal setting, the car wouldn't start. He checked the #1 cylinder for balancer match, performed a compression test, and a "leak down" test and everything was OK. The distributor needed to be rebuilt, as well as the balancer, so we sent them out to the experts to do that work. He then set the distributor to factory specs and reinstalled it. He replaced the incorrect timing cover with an original cover that I found online.

He then found what he believes was the primary problem for the poor performance, starting issues and the pinging. Apparently the "pole piece" in the distributor was wired backwards in the harness connector. He rewired the harness connector and that fixed the performance, pinging, and starting issues.

Since we decided to change the timing cover to a correct original, we also decided to replace the leaky non-original water pump with a correct pump that I found online, while everything else was apart. And since we had the cover off we also replaced the loose timing chain at that time. We also replaced the sparkplugs with a set of R44 (NOS) sparkplugs that I had purchased some time ago.

The last thing that we discovered during the time it took to perform all of the above repairs was that the starter was not original (from a 1961-62 Oldsmobile passenger car) and also had a broken mount. I purchased a correct starter online and that brings us to my original post. The old starter didn't seem to have any value so I gave it to a recycler for disposal. Sorry I did that.

Last Mark, the problem was recreated on the bench, so I think that you're correct in your assessment that the issue is with the starter or solenoid. However, it also seems to possibly be a heat issue and that's why we're going to proceed as I stated in my June 4th post.

Oh, and by the way, the LT1 runs great. It starts right up (when not hot), it has tons of power and it doesn't ping. Now if we could only get this starter problem addressed...


Thanks.

[Mark E.]

Re: D981 Starter Solenoid

Ken,

Thanks for the detailed background regarding how you addressed the performance issues you encountered. Reading about this type of real-world problem solving is a good learning for current and future readers of the forum- like me.

I like your approach of proceeding with "plan A" first (making sure you have a good solenoid and installing the factory heat shield). Bringing the starting system up to factory specs is a good starting point (pun intended).

You didn't mention your exhaust- be aware that mods like headers or replacement exhaust pipes inadvertently routed too close to the starter might contribute to a heat soak problem.

Is 42 deg BTDC the initial or total advance setting? I ask because too much initial advance can cause starting problems like slow, labored cranking. After replacing/repairing your timing chain, timing tab on the front cover, distributor and balancer (all of which will affect timing or indicated timing), do you now have more normal settings for ignition timing?

[Mark E.]

Re: D981 Starter Solenoid

One more thought:

Swapping out starters can be an inexpensive "tool" for further trouble shooting. I just bought a rebuilt Delco Remy starter with solenoid for by 70 Corvette with a lifetime warranty from Autozone for $35 plus $15 core charge (plus free shipping and a $20 gift card!). And it cranks my 454 like crazy. What a great country.

[Kenneth H.]

Re: D981 Starter Solenoid

Mark, the 42 degrees BTD center setting was what it was when I was having the problem. It was the only way that I could start the car. The timing is now at 10 degrees BTD center, and it runs great. The exhaust manifolds are original to the car, as are the exhaust pipes that attach to the manifold. The pipes are in pretty bad shape, but the mechanic made some temporary repairs using JB Weld, until they can be replaced in the fall.

If plan A doesn't work, your idea about purchasing a new starter for testing purposes has merit. The $50 would be well spent to isolate the problem.

Thanks.

[Mark E.]

Re: D981 Starter Solenoid

The exhaust manifolds are original to the car, as are the exhaust pipes that attach to the manifold. Thanks.

It's very impressive that you have the original exhaust pipes on this 45 year old car! In spite of your troubles, it sounds like you have a real cool '70 LT-1. And it's good to know it has a caring owner.

I've heard (maybe in the TIM&JC?) that the original exhaust pipes in our '70s were double walled. Can you verify with yours? Nobody (that I know about, and I've looked) makes reproduction, double-walled exhaust systems for these cars. I've also read (again, maybe in the TIM&JC?) that the exhaust note is different with the double wall construction.

I believe Chevy used double wall exhaust to reduce heat transfer from the pipes to the engine and passenger compartments. Maybe another reader who knows more can confirm/deny. If so, this is another element that affects the amount of heat to the starter.

[Kenneth H.]

Re: D981 Starter Solenoid

Mark, the pipes that I believe are original are just those that are attached to the 2" exhaust manifold outlet and expand to 2 1/2" into the rest of the exhaust system. The remainder of the exhaust system has been replaced. The car is in the shop right now, getting the starter reinstalled, but I wouldn't know what to look for in any case. However, I'll bet my mechanic will know, since he worked on the pipes a few weeks ago. I'll ask him this weekend and let you know. Also, there are a bunch of guys on the site (Joe L., Terry M., etc.) who are true experts when it comes to this stuff and will be able to answer your question about the pipes' original configuration. They'll probably chime in at some point.

That's also a good point about the heat transfer from the pipes. Another something to consider.

Thanks.

[Terry M.]

Re: D981 Starter Solenoid

It's very impressive that you have the original exhaust pipes on this 45 year old car! In spite of your troubles, it sounds like you have a real cool '70 LT-1. And it's good to know it has a caring owner.

I've heard (maybe in the TIM&JC?) that the original exhaust pipes in our '70s were double walled. Can you verify with yours? Nobody (that I know about, and I've looked) makes reproduction, double-walled exhaust systems for these cars. I've also read (again, maybe in the TIM&JC?) that the exhaust note is different with the double wall construction.

I believe Chevy used double wall exhaust to reduce heat transfer from the pipes to the engine and passenger compartments. Maybe another reader who knows more can confirm/deny. If so, this is another element that affects the amount of heat to the starter.

You are right in that the original early C3 exhaust pipes, and not just on LT1s, were double walled. Early over the counter replacements were also double walled. I don't know the real reason for this configuration. It might have been to temper the exhaust note, or it might have been for increased longevity of the exhaust system. It had to add some additional cost to the exhaust system, however, and such incremental cost would not have been made without some justification.