built on a budget 68 satellite with a rebuilt 383 that was sitting a few years. mild 400hp build, medium lift cam(was told, not sure of the specs.) it's a little hard to warm up... thinking alt field wire supplied choke opens right up and idle speed adj screw still too low?

once warmed up it's running ok? kinda stumbling on and off. have an older mp dist timing set about 12 btdc which i think is in the recommended range and sounded best when timing... couldn't completely get rid of the stumbling? once vac advance hooked up didn't change the idle, could it be a carb related issue along with the stumble?

also not any noticeable vacuum at idle from the front ported vacuum port on the speed demon 750(float bowls both set at half and consistent.) holley blue running consistent 6psi 93 octane fuel pressure at the carb. pretty sure i've got idle adjustment screws close to right on (can't find a smoother adjustment when turning all four corners at idle.) was thinking of upping the timing more but my top end seems to run out of steam at 4500 rpm... trans is older 66 727 with a supposed shift kit, deep pan and a medium stall converter not sure if that's responsible for the loss of steam are these timing related issues? this is my first sort of car build... any help would be greatly appreciated, have to drive this ol girl 1300miles home and video it

OKAY, ported vacuum is not supposed to have vacuum at idle.

Have you cleaned out your fuel bowls and made sure the needle and seat assemblies are free?

Have you checked your jets for little pieces of crap that might be blocking them?

Have you squirted carb cleaner through all the air bleeds on top of the carb body?

Have you made sure your distributor mechanical advance is working?

I've personally had all of these things happen on a sitting car.

R.

Sounds like the carb could be freshened up...Esp on a holley style carb. Fresh gaskets, power valves etc will cure allot of ails.

maybe its starving for air with that rag covering the carb inlet..

Does it have the recommended valve springs for the cam that's in there?
Bought a 383 years ago and the seller had installed an aftermarket cam, but left the factory valve springs installed. It was all done by 4500 rpm. I installed the recommended springs for the cam and it pulled hard to 6000. Just a thought.

hey bud that rag is custom

looked all over, think i left the specs sheet in arizona but the 383 was built by a pretty good local engine builder. bored 30 over i think, intake port matched to stock heads with valve job (10 or 9-1) no noticeable valve assembly noise or pinging, mild springs/rockers set(hoping the builder made good decisions matching valve assemblies to cam?)
http://www.youtube.com/watch?v=JqDE1_pSjpA

cool i've been reading that ported vac doesn't register till the butterflies open, on my setup im understanding ported is a much better choice than manifold vac? the mp dist was an ebay buy so it was used, i was testing the rotor play and it seemed to have minimal play but slow to spring back? not sure how to check the mechanical advance? any advice or run some searches?

the demon had not been used much but sat for a good year or so. without opening it up, i gave it a good carb cleaner spray down/scrub and blew it out with an air compressor before installing. i've not opened the carb up yet but have heard the horror stories of bg quality control, hoping i got a good one.

so was out tooling on it last night shooting that quick video, checked the jets at acceleration from idle and jets appear to be spraying in the middle although pass side jet seems more of a spray less of a stream? was going to start opening it up to check for blockage when i remember hearing about mp orange box idle issues and higher rpm retarding... happened to purchase one from summit a couple months ago. i thought it a little coincidental that the rpm retarding happened at 4k similar to my lack of steam and my idle stumbling under 0 throttle, stumbling at idle only not during rpm increase gradual or rapid. maybe it's more like a slight miss intermittently. having an older mp orange box on the shelf swapped it which seemed to produce worse results hard start, while idling and stumbling on acceleration. when i did that also noticed moving the wires connected to the dual ballast resistor effected idle until it died, the originating point was the jumper wire connected through an easy inline clip? figure i'll hard solder the jumper wire into the top wire and redo the female connectors at the corrosion point on bottom in the vid. think that will help some of the issues?

figured fix these issues n see... hopefully it sorts out the stumble? can it easily fix the 4k rpm retarding by purchasing a parts store ignition module or is there an affordable one through summit? i'm done with ebay :/

sorry for the novel haha. hopefully have the wiring done tomorrow as long as i can use a parts store module? got some trans leakage to handle to haha

thanks for the help so far guys!
here is a video of the jets and idle after cleaning and re-soldering at the ballast resistor, also the older orange box made the idle even more erratic so i switched back. appears to sound smoother now... let me know what you think?
http://youtu.be/lMXA8xiiikM

checking the resistance of the ballast resistor found that the upper section's voltage is reduced to around 7 volts but the lower is still running upwards of 12 volts... i don't want to fry anything, going to pick up a new one anyways. by chance anyone know typically what the lower voltage output should be?

after reading about all these orange box issues i'm thinking of picking up this parts store module, would this be a better option than the orange box?
http://www.autozone.com/autozone/parts/D...ier=113894_0_0_

oh and in removing the float bowls for inspection should i have a new gasket kit ordered for re-assembly? new to these bg carbs not sure if it's safe to reuse the gaskets...

Thanks folks!

took the carb apart, didn't notice anything apparent but cleaned it up with carb cleaner spraying it all out. once it was back together the car wouldn't stay running, then wouldn't start and i noticed the jets weren't squirting at all... so took it apart again and the orange umbrella check valve was sitting in the bottom of the accel pump and had a slight tear at the very edge, one on order now. not sure if that could be the issue or if in cleaning it i accidentally tore it up? before i took the carb apart i did notice the fuel bowls would be empty the next day?

also forgot to mention the ammeter was acting odd, it would swing 1/4 of the way right toward charge when the motor stumbled. plus it would swing all the way over to discharge when revving??? i checked the voltage at battery at idle voltage was only about 12.11v, when rpm increased so did voltage to over 14v. checked the brand new 78amp alt, 1 field wire grounded other field wire shows 9v give or take. output voltage at batt stud is only bout 11.6v give or take. do all these readings sound close? also made sure i didn't reverse anything on the ammeter and that my fuel pump was powered from the alt side. i have also done the nacho bypass and don't see any damaged wires from before.

any help is greatly appreciated, thanks

thanks for the quick response robert checked the wiring this morning and it appears correct i think... battery side 2 wires run to "D" post and alt side 2 wires plus wire from my fuel pump relay run to "C" post? i will double check tomorrow morning and snap a pic or two. funny thing i think my ammeter was functioning better before i swapped the orange box for a stock module and the old volt regulator for a new one. i'll swap back one at a time. think either of those malfunctioning could cause the ammeter to act oddly?

oops sorry sometimes i'm not so great at explaining what's in my head haha. at idle of a little under 1000 rpm the multimeter read roughly 11.6v when testing the battery post at the alternator, it was fluctuating though but never hit 12v. when testing with the multimeter at the + and - battery posts it settled at 12.11v but did increase when revved.

hopefully the check valve comes in so i can continue testing

The Autozone module will perform as good or better than the orange box. I ran a NAPA ignition module for several years on my last Duster with no problems at all.

Your not charging right as a running car should have 13.5 or 14 volts, anything close to 12 is just batt voltage with no alternator.

oi sorry rapid, that's better than ladies calling you "limited" lol. you were right i swapped the wires when hooking them back up at the ammeter, oops haha. the 2nd wire i have hooked to the batt side of the ammeter goes to the top post on the stater relay like in nacho's parallel setup.

surprise, surprise the autozone voltage reg seems to have been the culprit... after swapping it out with my old one the new voltage numbers are as follows.
before car was warmed up the; battery posts read 12.5v, the alt batt post read 12.4v and the field wire read 9.8v and at the volt reg it read 11.6v.
after warming the car up, adjusting timing and idle screw idle sat about 950rpm; the battery posts read 13.1v, alternator batt post read 13.3v and field wire read 10.8v, volt reg read 12.2v and i checked the dual ballast as well(top left read 12.1v, top right read 7.9v, bottom in and out both read 12v.)
all readings had some fluctuation .1v or .2v.

the motor seems to idle a little better now. maybe i'm paranoid but i still think i hear a slight stumble/miss. thanks for the advice so far, i will upload a video soon guys.

so fellas how are my numbers sounding, is the voltage still too low?

and here is the video http://youtu.be/fcZ4n0Nt5nE

how does she sound folks?

It sounds like its idling too high to me, 1000 RPM is a little high unless you've got a pretty decent cam so that may be why it sounds high to me. It sounds like it'd be more of an "idle" at 850 rpm or so. Idle it down and see how it runs. If theres a problem knocking it down to 850 or less should make it obvious.

Hard for me to hear a stumble on video. I noticed its a bit shaky but thats not necessarily abnormal, depends on the cam.

I'd also bump the timing up and see how it responds. If you've got any kind of cam it should like 15 degrees or more at idle. If the engine idled pretty smooth with 12 degrees you definitely don't have enough cam to need a 1000 rpm idle.

thanks rapid! i guess my charging system checks out, whew. one gremlin down... who knows how many to go haha.

just happened to find my cam card looks to be a crower 32240. intake/exhaust: 260/267 degrees with .456/.477 lift. should i bring the idle rpm down for this cam?

thanks for the reply matt! i was thinking it sounded too high myself but at lower rpm idle it was hard to keep running until warmed up. once warmed up, when i gave it a little gas and released the throttle completely sometimes it would hesitate before idling again??

when adjusting the timing i advanced it up to and over 15 but thought i heard a slight ping/tick and it didn't seem as smooth so i brought it back to around 12. the first video link i posted was closer to about 850rpm... however i'm not sure how accurate my sunpro II tach is either, after all it was just something that was sitting around the shop

Thats pretty much a stock or RV type of cam. It should definitely be able to idle lower, and 12 degrees or so may work best for that cam. You may have had ping with more, depending on the curve of your distributor, but thats another can of worms.

I would think that your engine should be able to idle at 800 rpm with relative ease. If it start stumbling and doing weird things when the idle comes down that far then you've likely still got a carb issue, OR a vacuum leak.

When you'd hit the gas and let off, did it act like it was going to die or did the revs kind of hang up high for a second?

The cold running issues could be related to the choke operation or you may have a block off intake heat cross over. They also could be related to any gremlins that may still be remaining in the carb.