Sensors & Vacuum tubes

A

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
0
0
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
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
0
0
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:



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.
 

mhamilton

Frequent Racer
Jun 11, 2006
430
0
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.




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.




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.



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
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
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
 

George B

Daily Driver
Jun 4, 2006
46
0
0
Southern NJ
Nice Thread !

I appologize for stepping in, but this has been infinitly helpfull. I bought an 80' 4dr a few months ago and have been playing around w/ the 229. I got it running fairly decent, but I can see by the vacuumme routing diagram, I have a few misplaced. Mike, mine runs fairly smooth, no vibes. My problem: between 45 & 50, it almost seems the TCC locks up and disengages a few times until I exceed 55mph. Also around 35mph it seems the converter wants to lock up as it surges in & out untill I hit 40 or drop down to 2nd. I checked adjustment on the TV cable and it's where it should be. With 146k miles I guess I shouldn't complain. I have another car that I play with so I am really considering rebuilding the 229 (especially since my older sons will be driving real soon) It has enough power to move itself out of the way, but milage is lacking to say the least. I'm estimating I get about 13 mpg. I'll correct my vacuumme line routing and see what happens. Thanks again for the post!

George
 

mhamilton

Frequent Racer
Jun 11, 2006
430
0
0
North Carolina
Glad to help! I know most people dump the 229 off the bat, but if you don't need a race car, it's a competent engine. I know I don't need 300 hp to idle in traffic with the a/c running ;) And, it has enough torque to cruise effortlessly.

It does sound like yours has something a bit off... I usually see 20-21 mpg mixed driving, as good as 24 mph highway. EPA ratings were 19/26 .

I've had issues with the TCC hunting, but not as bad as you describe. I found that timing can affect how/when the TCC engages. I had problems with my mechanical advance, it was just frozen solid. Fixing that brought back power, economy, and performance.

It seems most people with an original 229 have not had the issues with vibration that I have. I rebuilt mine at 120k... the cam, rings, valves were all shot. That was 8 years ago, and I wasn't interested in a restoration back then. I should have balanced the crank, rods, and fit the bearings to GM specs :oops:
 

RADAMANTYSGPS

New Member
Mar 24, 2020
1
0
1
49
buen día para todos, y esperando que la situación de cuarentena por el tema del coronavirus sea prospero para todos.
Leyendo las preguntas y las respuestas atinadas que da el amigo mhamilton.
En mi caso tengo un Chevrolet Camaro 1980 V6 y en estos días de cuarentena me han enviado un servicio de mantenimiento de CUSCO PERÚ y no hay mecanismos mecánicos que conozcan muy bien el funcionamiento de este tipo de motores.
He estado buscando por Internet la conexión de los vacíos que van al carburador y no he tenido éxito sin embargo viendo las fotos que usted envía me parece que el motor de mi camaro es similar al suyo, en mi caso alguna vez cuando se llevo al mecánico desconectaron todas las mangueras de vació y las dejaron allí viene funcionando de este modo hace buen tiempo pero no me gusta como esta, quisiera tenerlo todo en orden mañana sacare unas fotos para ver si ustedes me pueden ayudar con las conexiones por favor.
mientras tanto un fuerte abrazo desde CUSCO PERÚ.