69 K66 Ignition

[Richard M.]

Re: 69 K66 Ignition

Well Lawrence, it appears our fellow member and TI specialist Mike Zamora has located a pile of NOS 207s.....

HERE

I'd get myself one of those little darlings if I were you. He has a make offer button so you may want to put on your negotiating hat.

BTW Check Mike's other listings as he has a nice inventory of TI items. Mike if you're listening... thanks for having all that TI stuff. It'll help lots of folks.

Rich

[Mike Z.]

Re: 69 K66 Ignition

Richard, yes I am here. I usually do not input because I have had my hand slapped for contributing because I own a restoration shop that sells parts also. At any rate, as a dealer for the Delco Reproduction line that had the repro TI coils; I sold these coils for like 10 years with very few issues, but the factory in China was lost a little over a year ago and it appears there will be no replacement. When I found that out, I bought out most of the TI P/N coils that Ken had. I still have some #203, 207, 210, 272, and several #176 (listed on e-Bay). Note; regardless of the embossed 3 digits (P/N), the internals are the same in all the coils.

For those that have not had good luck with these reproductions: most times I found the installed the coil to bottom out against the hot manifold-this drastically reduces the life of ANY coil, that is why GM suggested installing with an "air gap".

I carry any/all TI parts to rebuild your distributor, or the entire system, as well as rebuild services. This is a great ignition system, so it is worth getting it to work as the factory designed it. I set up distributors on a Sun machine to make sure all is within factory specs, which is what I recommend, but I do limit (reduce the advance slot on the pole piece) the total mechanical advance and keep the mapping on the conservative end of the rpm ranges to operate best with our crap fuel we have today.

[Richard M.]

Re: 69 K66 Ignition

Mike thanks for checking in. Glad you're doing TI as were losing touch with the old stuff.

Well, the repro coils I had both failed outside the shielding "oven" sitting in the air vertically, away from the manifold. Both overheated internally. IR gun near 250*. Just my luck, the norm for me often. This gave me fits trying to diagnose. After hours of working on it I put in a Napa IC12 in the "oven" air gapped, and got a year of trouble free casual driving. Only drawback was a bit bigger diameter so a little mod to fit.

Then I found a NOS 207, put it in the "oven" with the air gap. Full rpm launches and aggressive runs, perfect for the last 3 years and counting.

? Do you know where Dave gets his? I don't like to bother him with phone calls as I know he's busy like you.

Thanks,
Rich

[Lawrence S.]

Re: 69 K66 Ignition

Reviving this old thread. Got the old TI wiring harness out. No big surprises, found cool firewall marking in mint condition under the insulation at the driver side foot well.
Will be posting more pics as I move along, and will have questions I am sure.

Lawrence

[Lawrence S.]

Re: 69 K66 Ignition

I finished off installing the TI harness, new distributor, plug wires. I just confirmed the car would fire which it did but did not run smooth. Will work on timing etc tomorrow.
So nice to have all the stock equipment back on the car.

[Richard M.]

Re: 69 K66 Ignition

Lawrence,

Glad to hear of your progress. I know you've been eager to get that TI system up and running again. Good job! The engine bay looks good.

Yes maybe you have a rough running issue due to a non-TI related function.

What VAC are you using and do you have it set for stock Ported vacuum or did you convert to Full-time vacuum?

Rich
PS Just a FYI since you like stock(me too).....
Double check your AIM UPC U69 Sheet A7 which shows the configuration of the plug wire grounds at the valve cover bolts. I see it shows that 2-4 go to the forward VC bolt, 6-8 go to the 3rd bolt, 1-3 to the 2nd bolt, 5-7 to the last bolt.(the diagram is a bit unclear so maybe someone will confirm)

PPS I didn't realize the valve covers were chrome on 1969 L71's. I thought only used on L89/L88. But I'm more up on C2's vs C3's.

[Lawrence S.]

Re: 69 K66 Ignition

I got the car running real well now. No more bouncing static timing mark idles real nice at 750 - 800 rpm.

But I must be off a tooth on the distributor. I can only achieve 22* static before the VAC hits the plug wire stand on the passenger side. So I need to correct that.

Rich, the VAC is a "201 T3". I bought the restored distributor from Jon Shafer of KC Corvettes. I am happy with it works well so far. Once I get the correct static timing (Probably 12* I am guessing) I will map the timing. I hope to have all the timing in 36* at 3000 rpm or so.

I am still running ported manifold vacuum but will change that to full manifold vacuum soon.

I rebuilt the carbs last March. They were a leaky dirty mess. Car ran great afterwards, but now the pump shot is non existent unless I manually press down on the AP lever. I don't know if the AP cam is just worn or what? I took it off and inspected it. Looked fine? (Carbs are the original that the car was built with, dated to the car) Little back story...car shows 26K miles, and based on the condition of the car am thinking it is close to original if not original. And the 4.11 gear set would lend too low miles. Another symptom of this is when I turn the car off from it being hot it struggles to start back. (maybe modern fuel) If I shoot carb cleaner in the carb will fire up. If I manually work the accelerator lever no pump shot. I am trying to troubleshoot this without taking the carb off but may have to. What has me stumped is that I can push down on the AP lever and get a good pump shot but not from the accelerator lever on the side of the carb? I have adjusted the AP spring and screw several time to no avail.

Thanks for all the help.

Lawrence

[Richard M.]

Re: 69 K66 Ignition

I got the car running real well now. No more bouncing static timing mark idles real nice at 750 - 800 rpm.

But I must be off a tooth on the distributor. I can only achieve 22* static before the VAC hits the plug wire stand on the passenger side. So I need to correct that.

Rich, the VAC is a "201 T3". I bought the restored distributor from Jon Shafer of KC Corvettes. I am happy with it works well so far. Once I get the correct static timing (Probably 12* I am guessing) I will map the timing. I hope to have all the timing in 36* at 3000 rpm or so.

I am still running ported manifold vacuum but will change that to full manifold vacuum soon.

I rebuilt the carbs last March. They were a leaky dirty mess. Car ran great afterwards, but now the pump shot is non existent unless I manually press down on the AP lever. I don't know if the AP cam is just worn or what? I took it off and inspected it. Looked fine? (Carbs are the original that the car was built with, dated to the car) Little back story...car shows 26K miles, and based on the condition of the car am thinking it is close to original if not original. And the 4.11 gear set would lend too low miles. Another symptom of this is when I turn the car off from it being hot it struggles to start back. (maybe modern fuel) If I shoot carb cleaner in the carb will fire up. If I manually work the accelerator lever no pump shot. I am trying to troubleshoot this without taking the carb off but may have to. What has me stumped is that I can push down on the AP lever and get a good pump shot but not from the accelerator lever on the side of the carb? I have adjusted the AP spring and screw several time to no avail.

Thanks for all the help.

Lawrence

Lawrence, Great! I've been as anxious as you all this time to see you succeed. I feel good for you.

So here's what I would do. Yes you are likely off a tooth. I see the #1 wire in your photo and probably is near the right spot but internally it must be off a bit due to the tooth offset. Did you notice if the shaft lower gear dimple points to the ~rotor tip when the distributor was out? That could be a issue too but likely not since you got it as a restored unit. Since you need to pull it that'd be a good time to check. Well, I supposed you don't need to pull it completely to get the tooth repositioned, but only if you do that is. I know it's a pain to pull all those wire grounds at the shield bracket, etc.

I use a magnet tool when I remove/install those ground wire terminal nuts for peace of mind from them falling into unseen places. I have the magnet next to the nut when loosening and attach it like below to get it started when installing.
P4260043.jpg P4260040.jpg P4260041.jpg

Also, if/when you pull it to re-position it I'd suggest that's the time to change the VAC and the vacuum plumbing to Full Time vacuum. Stock ported vac used the MS201 15(maybe you had a typo).

You will want a B20/B26 VAC. It's a VC-1765 (or equivalent), spec is 0* @ 6", 16* @12", so if you're at about 14" full time vac it'll be a good match following the 2" Rule. That's what I've used in all of my L71 restorations. Results are exciting so to say. Engine idles better. Runs cooler at idle, traffic, etc. And hot restarts are a breeze. You'll love the change. It's one little subtle "non-typical" look..... You plug the Ported nipple on the side of the center carburetor and add a Tee at the vacuum choke break/pull-off hose and connect it to the upgraded VAC.

Here you can see the ported nipple blocked with the black plug and the Tee at the choke pull-off line and the hose then going into the pipe for the VAC.
P4020018.jpg

As far as the pump shot, yes something is wrong there or possibly bent. That adjustment lever and spring is quite sensitive so you'll need to evaluate that contraption. I've had similar issues at times and had to bend the levers to get it to shoot better from the throttle lever itself too.
PA100139.jpg

Since your carb is original your pump jets are likely sized right. I've had to increase them before on new Holleys. But this wouldn't cause the shot problem not happening, only if not enough fuel. This had caused stumble issues for me in the past. Those L71's are thirsty!

One other pump issue could be the check ball for the pump in the carb itself, with a piece of debris or a casting flaw preventing the ball to seal, then loosing the fuel in its little reservoir. Casting flaw was/is typical for the new Holley replacement 2300s. Hopefully the problem is not here and will turn out to be a simple adjustment for you.
PA100118.jpg

PA100122.jpg

Getting there.... Great progress!

Rich

[Lawrence S.]

Re: 69 K66 Ignition

Rich,

The VAC is an MS 201 15. I think I have a B26 in my inventory. Will check and replace the existing VAC. I will convert the vacuum. I changed it on my 69 Z28 and made a big difference and my 67 L79. I suppose I just forgot to do this car. Will be nice when done.

Yes, I agree those little ground strap nuts are a pain. Especially on a C2. They are a little more manageable on a C3, but no fun.

I did confirm that the gear dimple was aligned with the point of the rotor button. I had to pull the distributor out of my 67 L79 and flip the gear to get the timing set correctly. Once I did the car ran so much better.

I would guess, that I have trash in the AP check valve. I remember that little guy when I was rebuilding the carbs. I did not do anything there but clean it up well. I do like your idea of changing the AP lever angle. That may help out some?

Thanks

Lawrence

[Lawrence S.]

Re: 69 K66 Ignition

Rich,

I need to retard the timing more as I stated above. The VAC is hitting the passenger side plug wire stand. Do I need to rotate the distributor one tooth counter clockwise to pick more adjustment to retard the timing?

Thanks

Lawrence

[Richard M.]

Re: 69 K66 Ignition

Rich,

I need to retard the timing more as I stated above. The VAC is hitting the passenger side plug wire stand. Do I need to rotate the distributor one tooth counter clockwise to pick more adjustment to retard the timing?

Thanks

Lawrence

Lawrence, Yes move the gear one tooth CCW and that should give you more adjustment to move the VAC away from the wire bracket. Keep in mind your tach drive coupler is going to move too, but if all is properly set it should actually help.

I've heard of some cases of non-stock cam usage that actually creates a similar clearance problem if the gear dimple is pointing to the rotor tip. This requires moving the gear so the dimple is now 180* from the rotor tip.

Rich

[Lawrence S.]

Re: 69 K66 Ignition

I believe this is one tooth CCW from where it was. Look right or too far CCW? I guess will just have to test and see?

[Richard M.]

Re: 69 K66 Ignition

I believe this is one tooth CCW from where it was. Look right or too far CCW? I guess will just have to test and see?

Lawrence if the #1 position of the cap is to the right of the rotor tip I'd say you are in range. The VAC now looks centered between the intake and the plug wire bracket.

I see you still have the MS201 15 still there. If that is a reproduction I suspect it's the B1 renumbered. I had one of those and it was way out of spec and when I bench tested it with a MityVac it would start advance at around 12 or more and wasn't all in until around 19 or more IIRC.

See my notes in my old L71 thread in THIS post along with THIS post which Duke replied with the OE specs.

So if that's a repro and it's still the base B1 VAC in disguise, it will never advance on the L71 which typically runs at approximately 14" vacuum.

If you have a B26 it may be a good time to do the Full time vacuum swap. BTW your static timing with VAC disconnected and source vacuum hose plugged can be set around 8* BTDC for initial testing. If you set the Balancer mark at 8* BTDC on the timing tab, along with the distributor cap precisely set with the #1 position in line with the rotor tip, it should get you right there on restart.

Rich

[Lawrence S.]

[Richard M.]

Re: 69 K66 Ignition

Ok good. IIRC I ended up at 8*-10* static which yielded about 25* with VAC connected to full time vacuum at idle. I stayed a bit conservative to avoid detonation issues if the car ever got tanked up with a lower octane blend.

The engines have been happy ever since according to my friends that own them.

Rich