Hey guys,
I've been putting alot of work into my 273 Cuda lately. All new ignition, timing was checked, carb ripped apart and cleaned well, etc. Finally have the idle set where I want it, however when I put it into gear with the brakes applied the engine rpm drops to rediculously low levels. If I turn the rpm up higher the torque converter catches and it stalls, any lower and it idles too rough. Any suggestions? Thanks.

 

NY -

Start by looking for vacuum leaks.
Timing and missed firing order would be second.

Archer

 

Is camshaft stock to mild?

If it has distributor vacuum canister, put on a vacuum gauge and timing light to see how each reacts in and out of gear, you will need a helper.

Do you have good control of the carb with the idle mixture screws? Turn them out for too rich and should run rough, turn them all the way in too lean and engine should stop.

 

The engine is totally stock as far as I am aware. I had an old timer help me set the mixture screws and I'm happy with where they are. The timing has been set with a light to stock timing. As for vacuum, I have searched thoroughly and found no leaks. I dont have a vacuum gauge, however if you pull a vacuum line and place your finger over it, it about pulls you in. So I'd say it's ballpark.

 

You must find out if your vacuum advance is working and what timing numbers with and without at idle and off idle.

What carb are we talking about?

 

The vacuum advance is working. If you disconnect it the timing changes quite a lot. With it hooked up it is at proper specs. Makes me almost wonder if the torque converter is too tight. I don't see why else it would change only when put in gear.

 

A proper diagnosis for me would be with instruments on to see what the engine is actually doing, anything less is just a guess.

You could try putting the axle up and putting it in and out of gear, and see what happens.

It just may need more initial timing which is common with new gas and old timing specs.

 

Okay thank you for the input. I am new to working on cars, so I really appreciate the help. I'll say that it has come a long ways since sitting in my grandfather's barn for 20+ years. And is totally drivable. I suppose I will try to find a local shop that has all of the instruments to check it out. Thankfully the compression on all the cylanders is an even 130 psi. Maybe I'll pick up a new carb as well. That old Carter is pretty shot.

 

NYCuda... You hit on one note I caught onto... Double check to make sure the Vacuum advance hose is hooked up to the rite fitting on the carb. It should be what is called ported vacuum.... From what I gathered from what you posted... I assume at idle if you pull the advance hose off its source. The Idle drop's? Correct?
If that is the case. The hose is not connected to the correct port for vacuum advance. and to me that is where the problem lies....

Just my 2 cents..

 

Hmm that is interesting. There are only two vacuum lines to the carb. One large to the PCV valve and a small one to the vacuum advance. I have an original diagram for the carb and I have it hooked up correctly according to that. I would think that pulling the vacuum advance line should slow the engine down and change the timing, as it retards it. So I am slightly confused.

 

Good deal... Just checking.... Sounds like you are good to that point....
Carry On..... While I scratch my head...

 

Thanks for the help man. Since the idle is perfect when in neutral, but drops so hard when put in gear I am leaning more toward transmission. Like the torque converter biting too much at idle.

 

Could be..... I would think all things in good working order..... The RPM drop should be only like 200-250 RPM from out of gear. To when you put it in gear?

Just my 2 cents

Is it a 2 Barrel DDB Carter Carb?

 

Yeah I would say that is close. Maybe I'll screw with the idle a bit more. And yes it is a Carter 2bbl. Wish I could afford a new one!

 

Ok.... I had to run out to the shop to check on something....lol

 

Haha thought you had one?

 

Looks to me like they called for the following
Timing 10* BTDC....
Curb Idle in Neutral of 500RPM.

I myself think that might be a little un-realistic for today's fuel and that carb settings and jetting's... But I could be wrong... I think its going to require a little higher settings. More like 500 in drive to me..... And when you take it out of gear if it goes up to between 500 rpm's and 700 rpm's I would say it good to go.... Unless you really start climbing in it's azz and start re-jetting and fine tuning it for better Volume efficiency for the engine...

Now with that being said... And back to the trans.... I would agree some of the convertor mfg's do get them a little tight.... But I would say to check the band adjustments to make sure there proper first..... ( I Assume this is the Aluminum 727 T.F.??)

Just my 2 cents

 

Yes I timed it to 10 BTDS, it seemed to help it quite a bit. I'll try raising the rpm a bit at idle. And no it is a 904 Torqueflite