hi guys ,i was wondering what some of the symtoms could be from a bad torque convertor ? after taking the 72 cutlass out yesterday (stock 350 motor and turbo 350 trans )i noticed it was quite a dog off the line .if i try to power brake the car it just bogs heavily .if i just stomp on it the car takes off slowly until it reaches about 2500 rpms then takes of like a rocket .could this be torque convertor issues or maybe a vacuum advance problem ?btw it has the factory convertor in it .when i first finished the car it would smoke the tires at will.thanks for any input.

 

Bad torque converter usually has a vibration, slips, and/or makes noise. Doubt its your torque converter. Make sure timing is advancing properly and your throttle is opening all the way.

 

Thanks Eric I've never had a torque converter go bad wasn't even sure of the symptoms I will look into the things mentioned . Maybe it's time to upgrade the old points system to hei with adjustable vac advance

 

Verify dwell and timing settings. The advance plates and vacuum advance cans sometimes freeze up preventing it from moving. Through a timing light on the engine and see what its doing. Make sure your throttle is opening all the way when the gas pedal is pushed to the floor.

 

As Eric says to do, do the simple things before jumping to the more complex in-depth and expensive things. Once you've determined you do not have a fuel or ignition problem get back to us and we'll guide you on how to accurately troubleshoot transmission problems before going through the trouble of tearing the driveline apart for nothing. Look for as many visual clues in both the above-mentioned systems before further road testing. The only caveat I will add is...you will likely need to road test while troubleshooting. The problem here is if in fact, your converter is coming apart it will cause further damage. I'd suggest performing a trans line pressure check and dropping the pan to look for metal. If these 2 things are in spec then continue with fuel and ignition troubleshooting.

 

I did check dwell and timing set to 12 degrees btdc and dwell at 30 degrees seems to advance when I give it throttle , pulled the plugs and they're a nice tan color . Choke works well , although I have to pump the gas quite a bit for a cold start .

 

Are you getting a good squirt from the accelerator pump looking into the carb and operating the throttle with the engine off. Is the choke fully disengaged when warm to allow the secondaries to kick in.

 

Yes a good squirt, has a new accelerator pump in it and yes the choke opens fully after warm up .sitting in park I can throttle it and four barrel opens right up .secondary air flaps seem to have the proper tension on them and are opening under hard throttle.

 

The secondary air door should not open when the engine is revving in neutral. If it is opening, the air door tension is too light.

 

ok thanks ill see if i can adjust them a little tighter

 

I typically adjust the air door tension by going WOT from a dead stop and keep adjusting until I get the best launch with no bogging. Many times just 1/8 turn of the screw makes a difference.

 

What kind of a range is there between too tight and too loose? It's hard to tell by pushing on it but it seems about the same as my 76

 

Too tight is when you feel the power loss(lean). The (Quadra) bog means it's opening too soon(rich). The (AVS) valve senses the load on the engine according to throttle position. The vacuum created under the AVS when the secondary throttle blades open act on that spring tension which unseats the secondary metering rods via a cam. So it either delivers the secondary fuel metering early (lose spring), late (tight spring) or just in time as the engine asks for it. You're looking for that sweet spot.

 

Did a couple things over the last couple days . Did upgrade to hei eliminated s wire and ran full 12 volts to the distributor .set the timing to 12 btdc . Took the car for a ride and it felt great , but still a dog off the line .moved on to the secondary air flaps (they did seem a little on the loose side ) so made four separate adjustments about an eighth turn on the screw each time , testing after each adjustment . The flaps were getting firmer but no change in performance .may have to stop obsessing over it . I'm convinced it's a carb issue .

 

12btdc is not going to be enjoyable, you need to set the distributor up right. Disconnect the vacuum advance until you can get it limited to 10*. Set your initial to 18* for now. Do you have an adjustable timing light?

 

No I don't have one is there a way around it?

 

Timing tape, but thats a pain in the a$$. I've used one just like this one for over 30 years. Make sure what ever you buy that it is an advnce (adjustable) timing light. Do what I said above for the time being and you should spin the tires.
http://www.ebay.com/itm/Sears-Crafts...0AAOSwt0FZApku

 

Yes, you can make marks on the balancer.

Turn the engine until the balancer mark is beside the 0 notch on the timing tab. Draw a line on the balancer next to the 10º mark on the timing tab. Use a white china marker, grease pencil, or pain pen so the mark is visible.
Turn the engine until the 10º mark on the balancer aligns with the 0 notch on the timing tab.
Draw another mark beside the 10º notch on the timing tab. Now you have the balancer marked at 20º.

So now, you can use your timing light to set the timing using the marks plus the timing tab.

 

I agree 12 degrees is rather sickly . I did add the marks as fun suggested until I get the proper light. Set it at 18 initial . Then off to work will test drive it tonight .

 

Disconnect the vacuum advance and plug the line for now. The vacuum can may have too much advance built in and you'll get detonation under light load.

 

Ok so I unhooked the vac advance and plugged it . Set the initial to 18 btdc ,runs better but still can't spin a tire. ��