Sensors & Vacuum tubes

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Anonymous

Guest
Ok, 81 Malibu V6 229 chevy, trying to plug and or delete all the extra hoses and sensors.

Which one on the dualjet carb is used for the vacuum advance?

On the intake manifold there is a connection for the brake booster, could I use a connection off the valve cover to run to the booster?

I unhooked a plug from the ecm wiring harness to the trans on the drivers side, wondered what that was for?

Thanks,

Trickbu
 

mhamilton

Frequent Racer
Jun 11, 2006
430
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North Carolina
The 229 non-computer is a bit more complex than the V8s. The vacuum advance is supplied by a vacuum regulator valve, which takes both manifold and ported vacuum, then provides the dist with one or the other depending on conditions. Fortunatly, you can get the valve: part no RV4 from RockAuto.com. http://www.rockauto.com/catalog/x,carcode,1055247,parttype,5176

You could go with straight ported vac, though idle would be rocky. Might try manifold vac, see how it runs with that.

Normally the nipple in the intake runner is for HVAC, cruise control, or transmission modulator. If you mean the vacuum connection for the PCV, that wouldn't work too well... the PCV will bleed off too much vacuum at the end of the hose.

The wiring to the trans is for the Torque Converter Clutch lockup. Really shouldn't run the trans without the TCC, as it is part of the oil cooling circuit. Won't kill it instantly, but will shorten its life and you'll loose economy. The non-CCC had a vacuum switch on the fender to control TCC.

Hope this helps,
-Michael
 
A

Anonymous

Guest
Thread starter
Mike, yep if it was a V-8 that is easy, but this darn V-6 had so many connections, and stuff...

Now I understand on the Vacuum regulator, except what the delay would be hooked up to?

The brake booster I think I will just leave that tube from the intake in place.

The wiring for the torque converter clutch I will have to figure out someting for that, did the non CCC for 1980 use a wiring harness for the tran that connects up from a vacuum source?

Thanks,

Trickbu
 

mhamilton

Frequent Racer
Jun 11, 2006
430
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North Carolina
"Delay" goes to manifold vac, "carb" goes to ported vac, and "dist" goes to the dist. Actually, the V6 vacuum setup uses two seperate vacuum switches (intake air & coolant temp) to control vacuum advance during warmup.... but probably more than you want/need at this point.

Yes, the non-CCC have a control circuit for the TCC. A tee in the canister purge control line provides ported vac to a delay valve/control switch on the inner fender. +12v is supplied from the brake switch, through this switch, down to the trans.

Here is the '80 vacuum diagram, this may help you:

3.8V6vacuum.jpg


If you want pictures of the actual vac lines on the engine, I can take some for you. A few years back I spent a long time sorting my vac system out. I'm happy to say that when it's put back the way GM designed it, the car starts and drives very well.
 
A

Anonymous

Guest
Thread starter
Mike,


Pictures would be excellent!

Thanks,

Trickbu
 

mhamilton

Frequent Racer
Jun 11, 2006
430
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0
North Carolina
Here's a shot of the TCC switch (the split loom on the vac hose is something I put on). The wiring to that switch goes back to the main engine harness. If you find a car with that switch, be sure to grab the 4-terminal brake light switch. It has the normally-closed switch needed to supply the TCC with 12v. Some cars had this for the cruise, yours may already.

tccswitch.jpg



Here's a look at the carb hoses. Ignore the direction of my vac modulator valve, it's an older replacement part with one of the ports on the wrong side. The part I mentioned above is identical to the GM part.

The hose bottom right of the carb (in this pic) is the ported vac for the dist. The one on the bottom left is ported for the EGR, canister purge, and TCC switch. The EGR TVS is under there somewhere... the large 4-port TVS on the thermostat is specific to the 229.

hoses1.jpg



The 2 vac hoses on the back of the carb are manifold vac. One goes to the "Delay" port on the vac modulator, the other to the air pump diverter valve.

hoses2.jpg


Let me know if you want anything else specific, or a closer look. I know it looks like a jumble of spaghetti in there ;) Also, a good place for 229 vacuum parts is the Canadian engines. Their cars didn't get CCC until much later, so those 229s are similar to the the US '80s.
 
A

Anonymous

Guest
Thread starter
Mike, thanks those pic's do help out quite a bit! I may have a couple other questions, but those do provide a lot od details. I don't think mine has the thingie on the drivers inner fender from the canister to the trans? does it connect up to the trans with a 4 prong connector?

Thanks,

Mitch
 

mhamilton

Frequent Racer
Jun 11, 2006
430
0
0
North Carolina
No problem, let me know if there's anything else you need.

The CCC models won't have the fender switch. The computer controls TCC lockup.

I have a 2-pin connector to my trans, but there is only one wire. You can splice your existing 4-pin trans connector to the vac switch if you want. The transmission is very simple--put 12v into that socket and the TCC locks.

You may be able to get that vac switch brand new, I think I've seen them in catalogs like Summit (maybe?). Was thinking about it, you probably have the brake switch wiring already in your car. Just need to find the wire that feeds 12v with the brake released, and wire that to the vac switch. Then from the vac switch down to the trans.
 

mhamilton

Frequent Racer
Jun 11, 2006
430
0
0
North Carolina
Oh, forgot to ask you, does your 229 run smoothly on the highway? Any vibration through the steering wheel? Does it idle rough when stopped in gear?

I ask just about everyone with a running 229 if theirs runs smoothly... have yet to find the problem with mine.
 
A

Anonymous

Guest
Thread starter
Good question, I have not had it out on the highway, only backed out of the driveway to turn it around a couple of weeks ago. Today I was working on it and actually had it running pretty good for a little bit, I think the CCC carb is still causing some trouble, once I replace that, and get the trans wiring figured out I can take it for a test ride around the block.

Trickbu
 

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