[Judge273]

Anyone have some information or a diagram for 72 vac, elect. ? Can you show some pix of the routing and provide the info on what it does?

72 has some strange things, and maybe similar on all engines too? Here "redmark questions as to whats this thing" on a 72??

They are on a 400 that might be same as 455 HO in 72?





Is the shroud the same for a 455 HO too?

[njsteve]

LOL. Usually the question is "What should have been here?"

Your car has all the rare parts intact. The TCS solenoid is the contraption behind the carb. The pass side head has the temp sender for the TCS system. The sender on the drivers side is the temp gauge sender. The very expensive and very fragile, black plastic topped sender on the front of the intake is the vacuum purge valve that routes to the charcoal cannister.

I have diagrams in my 72 T/A "power wash" thread at the top of this section. If you do a search on "TCS" you'll locate it.

[Judge273]

Actually Steve, I can ask that question as my new car doesn't have the TCS solenoid.

Are they available still?

Probably why my vacuum routing goes to strange places on mine. haha

That vacuum sender also goes to the carb base port too? Just two places?

I did look at your thread. Very helpful! Clip on valve covers to hold wire on yours correct compared to mine? Is it on both sides?

Do you have a assembly or service manual on the whole TCS system?

See how funky it is...



Doesn't stop there.



That one line goes to port on carb which is for a auto. My PCV valve line goes all the way back to carb back too. haha

[Held for Ransom]

Mike, you need to look at Pat Browns site...
http://www.455-ho.com/

[Judge273]

Yeah, I'm going to have PB come over too! Man, he has the stuff as well!!

[njsteve]

Here is the routing:



Red arrow vac line goes from passenger side rear carb tree to rear of TCS solenoid.

Green arrow vac line goes from driver's side rear carb tree to the vacuum line that feeds the A/C heater doors. This line originates from the firewall. The green circle is where the vacuum filter is inserted so the two lines can be connected together. This is for A/C equipped cars. If you didn't have A/C your tree didn't have the driver's side branch. (See vacuum tree chart below). The correct "Type K" tree is reproduced.

Blue arrow vac line goes from the side port of the TCS solenoid to the vacuum advance canister on the distributor.

NOTE: the front of the TCS solenoid has a "nipple" but it is actually a vent that a small sponge filter press fits on to. It is not for a vacuum line. If you route a vac line to it you will cause a vacuum lock of the solenoid.

BTW, if hooked up properly and all the sending units function and TCS unit is working as designed, the car will most likely run REALLY crappy as this system was designed to limit any vacuum advance to only when the car was in 4th gear and the engine was running very hot. This system was designed to produce a reduced emissions test result for emissions testing purposes and had a deleterious effect on engine performance. As a result, I run the red arrow vac line on my cars directly to the distributor advance unit and then just make a dummy line from the rear of the TCS unit to the side of the TCS unit so it looks correct to the casual observer.



This is the 1972-only 3026085 vacuum purge valve that goes on the front of the intake. The top is routed to the charcoal canister on the passenger front fender. The side port is routed to the bottom vacuum fitting on the baseplate of the carb. They are extremely fragile and commonly break off at the base. They randomly pop up on ebay once in a while I got an NOS one recently for my car that went for $165

http://www.ebay.com/itm/NOS-THERMOST...p2047675.l2557



The 1114454 TCS solenoid is reproduced. Make sure you get the 1972 not the 1971 unit as the mounting brackets are slightly different.

http://www.ebay.com/itm/1972-Pontiac...p2047675.l2557






Here is the "Type K" vacuum tree for 455HO with A/C. These are also extremely fragile. NEVER try to pull a vacuum hose off of one that is attached to a carb: cut the hose instead. If you yank on the hose, the tree will snap off at the end of the threads and the threaded portion will be permanently stuck in the carb base. Also, you have to use Teflon tape when you install one because they will never "clock" themselves correctly and the nipples will be facing the wrong way. They are also prone to vacuum leaks at the carb base where they thread in, for the same reason.

[Judge273]

That's so awesome, thanks!

[Held for Ransom]

I recognize a couple of those pictures.

[njsteve]

Originally Posted by Held for Ransom

I recognize a couple of those pictures.

Yup, that's my old 72 T/A's engine. :-)

[Judge273]

Anyone know if this is a vacuum line to somewhere off dist?

[njsteve]

The blue arrow vacuum line in my photo above goes to the distributor vac advance nipple you have labeled in your photo.

P.S. i would definitely get someone to fully check out that distributor before running it in your car. The reason there are so few cars running them is that they were prone to overheating the module and/or coil pack and then crapping out and stranding you without any advanced warning. And the parts were super expensive even back in the day - like $200 plug wire set and $200 modules. It was much easier to throw in a $50 HEI and be trouble free.

I have a half inch thick stack of original owner dealer work orders from my car. It is funmy to read through because it seemed that he had to have the module and coil replaced at every oil change. Or basically every 3000 miles the car wouldnt start and he'd have them change the oil while repairing the distributor. If you go to my "Part Deux" thread I have a several pages dedicated to playing with one of these units.
http://forums.maxperformanceinc.com/...695444&page=40

[West Coast GTO]

Hello Steve,
A related (or maybe unrelated) question: for a car that did not come with a unitized distributor, would you recommend a Pertronix (or similar product) as compared to an HEI?

Originally Posted by njsteve

The blue arrow vacuum line in my photo above goes to the distributor vac advance nipple you have labeled in your photo.

P.S. i would definitely get someone to fully check out that distributor before running it in your car. The reason there are so few cars running them is that they were prone to overheating the module and/or coil pack and then crapping out and stranding you without any advanced warning. And the parts were super expensive even back in the day - like $200 plug wire set and $200 modules. It was much easier to throw in a $50 HEI and be trouble free.

I have a half inch thick stack of original owner dealer work orders from my car. It is funmy to read through because it seemed that he had to have the module and coil replaced at every oil change. Or basically every 3000 miles the car wouldnt start and he'd have them change the oil while repairing the distributor. If you go to my "Part Deux" thread I have a several pages dedicated to playing with one of these units.

[Judge273]

I agree with that from both the carb and dist perspective.

Because right now it runs fine with the HEI unit in there, and a 71 268 carb. Which has the port for the vacuum advance in front carb, and the 72 273 doesn't.

Lots of little quirks, but like I said runs and idles great, and has no TCS or ports in intake...

I will tackle those little things one at a time and get the dist looked over, and if possible rewired with the coil pack checked too.

The carb has been on shelf for years and bet rubber parts inside never had ethanol before either.

[PB]

Been meaning to do a spread on my site for the vac routing....need to get it up. Steve is right on the money with that vac line routing...and I bypass my solenoid just as he describes. Here's a pic of mine too for reference, with the solenoid taken out of the loop. In your pic above Mike, the vac lines are reversed from the intake purge valve...the top goes out to canister, bottom comes in from the carb.

[PB]

Intake thermal switch.

[njsteve]

Originally Posted by West Coast GTO

Hello Steve,
A related (or maybe unrelated) question: for a car that did not come with a unitized distributor, would you recommend a Pertronix (or similar product) as compared to an HEI?

On a points ignition car, the Pertronix or similar are nice because they keep a stock look. I used a conversion in my 1112126 point distributor in the vac routing photo and it looks just like the factory setup. The HEI looks like, well, like a big old HEI, but they do work nicely.

[grd777]

Originally Posted by njsteve

Here is the routing:



Red arrow vac line goes from passenger side rear carb tree to rear of TCS solenoid.

Green arrow vac line goes from driver's side rear carb tree to the vacuum line that feeds the A/C heater doors. This line originates from the firewall. The green circle is where the vacuum filter is inserted so the two lines can be connected together. This is for A/C equipped cars. If you didn't have A/C your tree didn't have the driver's side branch. (See vacuum tree chart below). The correct "Type K" tree is reproduced.

Blue arrow vac line goes from the side port of the TCS solenoid to the vacuum advance canister on the distributor.

NOTE: the front of the TCS solenoid has a "nipple" but it is actually a vent that a small sponge filter press fits on to. It is not for a vacuum line. If you route a vac line to it you will cause a vacuum lock of the solenoid.

BTW, if hooked up properly and all the sending units function and TCS unit is working as designed, the car will most likely run REALLY crappy as this system was designed to limit any vacuum advance to only when the car was in 4th gear and the engine was running very hot. This system was designed to produce a reduced emissions test result for emissions testing purposes and had a deleterious effect on engine performance. As a result, I run the red arrow vac line on my cars directly to the distributor advance unit and then just make a dummy line from the rear of the TCS unit to the side of the TCS unit so it looks correct to the casual observer.



This is the 1972-only 3026085 vacuum purge valve that goes on the front of the intake. The top is routed to the charcoal canister on the passenger front fender. The side port is routed to the bottom vacuum fitting on the baseplate of the carb. They are extremely fragile and commonly break off at the base. They randomly pop up on ebay once in a while I got an NOS one recently for my car that went for $165

http://www.ebay.com/itm/NOS-THERMOST...p2047675.l2557



The 1114454 TCS solenoid is reproduced. Make sure you get the 1972 not the 1971 unit as the mounting brackets are slightly different.

http://www.ebay.com/itm/1972-Pontiac...p2047675.l2557






Here is the "Type K" vacuum tree for 455HO with A/C. These are also extremely fragile. NEVER try to pull a vacuum hose off of one that is attached to a carb: cut the hose instead. If you yank on the hose, the tree will snap off at the end of the threads and the threaded portion will be permanently stuck in the carb base. Also, you have to use Teflon tape when you install one because they will never "clock" themselves correctly and the nipples will be facing the wrong way. They are also prone to vacuum leaks at the carb base where they thread in, for the same reason.

hi i would like to hook up my vac lines as you state in the post were you ran the red arrow line to the dist advance . do you have a photo of this set up
thanks