383 is running worse than ever

[onebadmopar]

ive got A 69 charger with a 383 4bbl edlbrock intake 750 edelbrock carb with electric choke (yes its working) at idle all is good sounds decent smooth throttle but when in gear its a whole other story under light accelration like moving from a stop it stumbles and almost dies unless i feather the throttle then it picks up weve checked the timing over and over and we are right on also disconnected advance plugged the line ,,no change. tonight i messed with the timing a little and bumpd it up a cple of degrees. made it even worse under full throttle car makes no power just kinda falls flaton its face everything is new in the motor rebuilt to stock except a 30 overbore had reputable machine shop do the build an we put the heads on and intake.. it appears it is also running a little hot but unable to actually comfirm it cause not trusting it yet to take it that far it all seems to be pointing to carb but its brand new also ive had it apart and we did find a dead beetle in it from having the aircleaner and hood off in the garage so long put it back together no change checked float level its right on we tried adjusting idle mixture screws also .. we keep going in circles that we are lost now..... anyone have any ideas at all this is getting totally frustrating

[craigandlynda]

just getting it going after a complete rebuild? wow...start w basics...do a compression test, this would tell if timing chain is off by a tooth...look for vacuum leaks...especially around manifold edge at head...and carb base...that'lll get you started...

[craigandlynda]

if you get thru those ok, check accelerator pump setup on carb...maybe you're not getting the "pump shot" when you step on the pedal...

[oldschool]

it sounds like the carb to me,or a really bad vaccum leak.
with it running hot and stumbling,it sounds lean.

[aifilaw]

sounds exactly like a vacuum leak, check your ports on the carb and your lines, block everything off at the carb to eliminate/troubleshoot

[onebadmopar]

im going to remove and reinstall the intake today do you guys use sealer onthe block then install valleypan then more sealer then intake?

[aifilaw]

That's what I do, but then again I have a modified street avenger and I don't use regular gaskets

[onebadmopar]

should i let the silicone dry before starting the car to see if theres any change?

[hutch]

should i let the silicone dry before starting the car to see if theres any change?

I let the silicone setup with the intake bolts on just a little better than finger tight then tourqe it down about 24 hours later so you dont just squeeze out all your seal.


But I dont know that that is going to cause the type of vacuum leak you are looking to trouble shoot.  Sounds like its something in your timing from your advance from the carb.

[onebadmopar]

actually i think it made a huge improve ment carb doesnt have that air sound it did ...to wet to drive it right now so tomorow but definatley see an improvement bad thing is i snapped off one of the little bolts in the front that hold the thin narrow plate down to the valley pan hoping i have enough sealer there to make it not leak

[aifilaw]

actually i think it made a huge improve ment carb doesnt have that air sound it did ...to wet to drive it right now so tomorow but definatley see an improvement bad thing is i snapped off one of the little bolts in the front that hold the thin narrow plate down to the valley pan hoping i have enough sealer there to make it not leak

Those three hold-down bolts do a little bit of a job, but as long as you put sealant down in a full bead all the way along that edge and you let it set then it should be fine with two or even one bolt holding it in.

By the way, it doesn't tell you this, or maybe it does, but here's an experienced hand at Pamela with some advice.

Anything that goes in an engine compartment or an engine use only one type, high-temp red RTV, even if you think it wno't need it, use it.

Put it on, tighten it down to 5 ft lbs, let it sit for 1 hour. Then tighten it down to 90% of its final torque, let it set for 14-18 hours. Do not start the engine before then, no matter how badly you want to "test it"
after that time, tighten it the rest of the way, drive around for a couple days, then re-tighten. Follow this procedure and you will do the job once, not 3-5 times over and over again, or just say "to hell with it" like most and "its an old car, its got leaks."

[onebadmopar]

thanks air .....course i couldnt wait and took it for a drive around my block  its better but still a slight stumble i think its timing now i think i have it set at 8 degrees and not 12 after lookin at the post i went above the 10 degree line a little ....thinking the closer to zero from the 10degreees before top dead center tab was higher i actually should be a little under the 10 degree tab almost to the end of the timing tabaltogether ..right?

[onebadmopar]

after adjusting the timing by ear listening for highest rpms and adjusting idle mixture screws slightly my hesitation is gone but at wop it still seems to lack power im using a lokar kickdown cable and had to attach a spring to it so it will return but anyone know the adjustment on this should the cable start to move as the throttle lever moves or does it start to kick in about mid throttle?

[mally69]

Well My grandpa had his timing chain off by one tooth, and let me tell you it sounds to me like thats whats going on here to. It seemed to run hot idled ok but when in gear sputtered for a bit and then full throttle it would just simply GIVE UP and fall completely on its face. And I mean a 4 cylinder nissan pickup would have been able to beat it. I would check that     

[firefighter3931]

after adjusting the timing by ear listening for highest rpms and adjusting idle mixture screws slightly my hesitation is gone but at wop it still seems to lack power im using a lokar kickdown cable and had to attach a spring to it so it will return but anyone know the adjustment on this should the cable start to move as the throttle lever moves or does it start to kick in about mid throttle?

The shift cable might need some tweaking.....it (kickdown) should be at maximum travel (or very close to it) when the throttle is wide open. 

Try shifting it manually and see how it performs. 

Fwiw, the idle mixture screws have no effect on high speed operation.....once you're past 1000-1100 rpm the carb is operating on the main circuit. 



Ron

[onebadmopar]

when i manualy shift it its awsum!!!  when i let it shirft its self its shiting way way to quick does it hurt it any to manually shift it ? its way more fun lol finally starting to get happy with it now

[mally69]

I have shifted mine manually for as long as I have had my car and it doesn't seem to hurt anything. I guess it all depends on how far into the pedal your foot is. I would get that kickdown linkage hooked up to where it can shift automatically  becuase if you don't you will burn the clutches out of your tranny.      Oh and one more thing if you like to do burnouts make sure you shift into second as soon as you can, first gear burnouts in a 727 is a big   

[onebadmopar]

well motor only has 50 miles on it so i dont think any burnouts are coming any time soon i tend to baby it but im sire once in a while i might get the urge....still alot to do to this car porobably never ends
noticed tonight gear oil leaking from left rear wheel so looks like axle seals are gone

[aifilaw]

Axle seals can be incredibly easy depending on the rear differential. What diffy do you have?

[onebadmopar]

8 3/4

[aifilaw]

yes, painfully simple.
Pull the wheels, unscrew the bolts holding the axle in place (there are 5 of them) behind the lug bolts, one of them (the bottom one, should have a retainer attached, don't lose that) and the whole axle slides out as one piece. That is all. FAAAAR superior to a chevy 10 or 12 bolt.....don't get me started.

[firefighter3931]

when i manualy shift it its awsum!!!  when i let it shirft its self its shiting way way to quick does it hurt it any to manually shift it ? its way more fun lol finally starting to get happy with it now

Well that pretty much tells you that the shift points need adjusting. 

Good to hear it's running better 



Ron