Hi, my 340 cuda with auto trans is stalling when put into drive or reverse.

I have fitted all new gaskets and new vac pipes so,no leaks.

Changed the holley too,but still stalls. timing is set at 10*btdc and idle

is set at 1000rpm. Still stalls if i raise the idle speed.

The only thing that i have found that makes a difference is to switch round the vac pipes and put the full vac onto the distributor instead
of the timed vac one. it cures the stalling, but i cant leave it like that
because it puts the distributor on full advance permanently !

So whats the answer............any ideas guys

 

is the 1000 RPM a warm 1000 RPM and cold 1000 RPM? (meaning is the motor fully warm of cold at this RPM?)

 

i think 1000 might be too high for an auto

 

What convertor and what cam do u have?
Might have a vacuum leak or timing mark may be wrong.
How much compression do you have? How big is the cam? Lower compression requires more advance at idle. Almost sounds like you dont have enough cylinder pressure at idle due to maybe too big of a cam or low comp. or combo of the two. Try disconnecting the vacuum advance and plug the vac. line. Then advance the timing another 5*. The idle should pickup, adjust it. Now try putting the car in gear. [dont drive it that way til you check the total timing]. Just try to get it to go into gear without stalling. You may need as much as 15* at idle. {more ?} Should be less than 38* at full advance. When you check the timing mark, you must find the actual TDC of the #1 cylinder and compare it to the actual mark on the balancer. Timing marks are not always accurate, its good to check them with a degree wheel and a piston stop. You might need a dist. with the ability to recurve it and/or adjust the total timing when all is said and done. tHIS IS JUST MY THOUGHTS OUTLOUD. Hope it helps. ENJOY!!!

 

I'm thinking it might not be enough, kind of like what the moparguy said.

 

I am going to go with timing being off relative to actual TDC.

 

Motor fully warmed up and idle set at 1000rpm.

 

Moparguy, thanks i think you may be my last hope !

The motor was rebuilt less than 2 yrs ago, everything has been kept stock
including the cam. standard spec trans. only thing added is an edelbrock
torker intake and holley 600cfm universal carb. definitely no vacuum leaks
i have replaced all intake gaskets and new vac pipes.Compression is good
at around 100+ PSI. Vac gauge reads 18 at 1000rpm idle,with steady gauge needle.

Will follow your advice on the timing and come back to you later.
Thanks again, Neil

 

A 1000 RPM when the motor is fully warmed up is good so i would say that it must be the timing.

 

you dont want idle speed to be to high on an auto, it'll put excess stress on it

 

Yep, I will set the idle to 850 and adjust the timing to see what happens !

 

I will check that one too Dude !

 

ya
that is probably where the problem is

 

Hi guys,
Well, i think i found the problem !

I took out the spark plugs to clean them, and i thought i would experiment with the gap size. the shop manual says .035" so i reduced it to .022"
and refitted them, warmed up the motor and put it into drive..........

and it didnt stall out !!!! So, either the shop manual is wrong with the

gap setting OR by reducing the gap size i have made the spark stronger,

which points to a weak coil.........am i right. what do you think ?

 

I'm wondering how fresh this motor is? Has it been broken in yet?

The reason I ask is the compression seems kinda low. Like to see at least 130 PSI. Sometimes when an engine is fresh, the rings have not been seated yet and it affects the PSI in the cylinder.

[Or the gauge might not be accurate]

 

Yes it could be ignition related

 

It sounds like a weak coil, usually .030 to .035 is a good gap range. If its only working at a .022 gap it sounds to me like a coil weakness. Check the wires while you're at it also.

 

Ok, Thanks guys for your input !

At least it sounds like im getting somewhere with this problem at last !



Will keep you informed of any further developments