Best guess as to what’s going on ?

[bcOH67]

67 charger. 383 4brl, has been bored for a bigger cam (so someone has been inside and altered things), larger oil pan, 3spd auto

This started happening about a month ago, before that no issues at all. Oil level reads good. Have the factory and aftermarket oil gauge for readings. While moving battery reads and holds at 14.1/14.2, when idling in D sometime will drop down to 13 range. Sometimes doesn’t drop down at all.

Start up when cold starts right up but will stall after a couple seconds if I don’t give extra throttle in park. After a minute or so will idle fine without stalling. Sometimes will stall again as soon as I shift into reverse.

Once it starts moving though everything is fine and operates like normal. But then after 15/20 minutes of driving (I’m assuming that just means at operating temp) if I’m sitting at a red light the oil pressure goes super low and will stall if I don’t rev it a little. Pressure seems to rise a little and hold if I shift into neutral at red light instead of in D holding break.

Like I said, things were fine before this problem started and I didn’t change anything. Any hunches on what I should look at would be appreciated. Thanks!

 

[Dave6T4]

I don't understand "bored for a bigger cam". It sounds like you are having problems with your automatic choke. This can be difficult to sort out, as it can only be done with a cold engine/carb. Low oil pressure with no loose bearing sounds could be cam bearings. Back to the mysterious "bored for a bigger cam" statement. It could be as simple as sticking relief valve in your oil pump. Big Block engines like your 383 have an external pump. Undo the plug at the rear of your oil pump, and pull out the spring and relief valve. Clean these with lacquer thinner, as well as the valve bore in the pump. Put it all back together, and see if oil pressure improves at idle.

 

[Don Frelier]

This could be almost anything.

But start with a couple simple things:
1. Idle speed screw, maybe it just backed out a bit?
2. Idle mixture settings
3. Check to make sure the carb is tight enough on the intake.

 

[oldbee]

How many miles since carb was rebuilt? (maybe some water got in the gas at last fillup?)

 

[oldbee]

AND,,, if you get the choke set right there should be no problem with putting it in gear and driving it right away. Ambient temperature cold or hot should make no real difference.

 

[twecomm]

For whatever it's worth... I have a 383 with Edelbrock 1406 carb and 727 auto tranny. About a year ago I had an erratic idle problem with idle, all of a sudden idle seemed to keep changing. I kept re-adjusting the idle but every time I started it, warmed it up, electric choke opened fully as it should after a minute or so, and drove it, in gear, the idle RPMs were different than where I had previously set it.
Saw a video on Edelbrock web site that suggested backing out and removing the 2 idle adjustment screws and blowing compressed air into the idle mixture screws holes to clear any deposits. Re-installed screws, 1 1/2 turns from bottom to ball park idle mixture as suggested. Then, properly reset idle mixture with vacuum gauge as recommended, and it was fine after that.. Idles about 900 RPM's and when in gear drops to 500 RPM's.
May or may not be your issue, but thought I would throw it out there.

 

[Don Frelier]

AND,,, if you get the choke set right there should be no problem with putting it in gear and driving it right away. Ambient temperature cold or hot should make no real difference.

Well if he has a larger cam and the original "tight" torque converter there is little room for error in tuning.

 

[bcOH67]

Thanks everyone!

As far as the bored for bigger cam statement- I don’t necessarily know what it means either. I am just trying to remember what they had in the description when I bought it. Said it is the original 383 but it is a 400 now. All I know about engines is they make the car move. Still learning, sorry. I just mentioned it to make it known that someone had it torn apart and did stuff to it.

The carb hasn’t been torn apart and cleaned for a long time, years. I will check the relief valve and screws and see what I can find. And clean/rebuild the carb while I’m at it. Good time to learn.

 

[Jerry Hall]

My recommendation is to do only one thing at a time. Doing multiple things before checking for a solution could lead to having to find someone to sort out the problems that result. If you only know that the engine moves the car, what do you know about what feeds the engine. I admire your interest in learning, just don't get carried away.

 

[Don67Satellite]

^^^This.

 

[Lefty71]

You cant bore out a 383 to a 400. Who knows what you got there??

 

[Kern Dog]

Hey guys, the OP admitted that he is just learning about this stuff. Lets see if we can explain things in a simpler manner to help him understand.
There are a lot of helpful people here but many of them, myself included, are used to speaking and writing to others that are of similar knowledge.
I can talk car stuff with just about anyone. I know the lingo even if I haven't done it all.
Put me around computer people....Holy crap I am LOST. Even some of the most basic terms might as well be in Mandarin or Cantonese for how much I understand it.
From what I'm seeing....
Old cars can be tempermental. All my old cars run a little rough when they are cold because I don't bother to have functional choke assemblies on them. The leaner the carburetor, the more finicky they will be when cold since the engine needs more fuel when warming up.
The oil pressure will rise and fall with engine speed. If you're idling and it starts to stall, lower oil pressure is expected.
You may just need to do some basic adjustments to the carburetor to avoid stalling.

 

[hofferwood]

While moving battery reads and holds at 14.1/14.2, when idling in D sometime will drop down to 13 range. Sometimes doesn’t drop down at all.

That's just the voltage regulator doing its thing---Worry if it drops to around 11 or goes up above 15 volts.

 

[twecomm]

All good suggestions here... When you crank to start the car, the battery is somewhat depleted of it's charge, so depending on how long you need to crank to get started, so goes the depletion of the batterys' charge. it's expected that the alternator will be generating more than 12 volts for some period of time till the battery charge is replenished, so seeing a higher voltage at the battery in this condition is normal. Keep in mind that with todays fuels, when engine is hot after driving engine heat causes some evaporation of fuel from the carb. With my 383, after a few days of sitting in the garage I need to crank for a while until some fuel gets pumped into the carb to get started.

 

[Darter6]

I agree with Kern. This is a great place to learn.
I will say diagnosis it really tough without standing next to the car it's self.
Best we can do is head you to a path, doing one step at a time as Jerry Hall suggests .

get the choke set right

Oldbee hit the nail on the head. Set it right and you should be able to drop it in gear after a minute or so.

That's just the voltage regulator doing its thing---Worry if it drops to around 11 or goes up above 15 volts.

This sounds normal not to worry. twecomm gives a good description .
Last is get to know just what you have,Engine, Ignition,Carb etc.

 

[bcOH67]

Not that this has anything to do with my issue I assume now, but now I’m curious as to what I may or may not have haha.

I found the listing: says “modified 400 engine, VIN is H code, bored and stepped up at least one cam” (again: don’t beat me if what I’m saying makes no sense, just reading the words haha), Holley 570, msd ignition, edelbrock torker intake, headers (that have been ported) 727 torqueflite.

It seems as though the carb is a good place to start so I’ll see what I see

 

[BSB67]

How long have you had the car?

This started happening about a month ago, before that no issues at all.

What is “This”?

Oil level reads good. Have the factory and aftermarket oil gauge for readings. While moving battery reads and holds at 14.1/14.2, when idling in D sometime will drop down to 13 range. Sometimes doesn’t drop down at all.

Oil level has nothing to do with voltage. Your car has an aftermarket volt meter ?

Start up when cold starts right up but will stall after a couple seconds if I don’t give extra throttle in park. After a minute or so will idle fine without stalling. Sometimes will stall again as soon as I shift into reverse.

You likely have a choke, or choke adjustment issue. Nothing to do with oil pressure.

Once it starts moving though everything is fine and operates like normal. But then after 15/20 minutes of driving (I’m assuming that just means at operating temp) if I’m sitting at a red light the oil pressure goes super low and will stall if I don’t rev it a little. Pressure seems to rise a little and hold if I shift into neutral at red light instead of in D holding break.

Could be a lot of things. Mostly tune up related. Unlikely unrelated to oil pressure. I would put new spark plugs in it, and turn up the idle speed

Like I said, things were fine before this problem started and I didn’t change anything. Any hunches on what I should look at would be appreciated. Thanks!

Again, not sure which problem is “this problem” as I think you have several unrelated things going on.

 

[Kern Dog]

Not that this has anything to do with my issue I assume now, but now I’m curious as to what I may or may not have haha.

I found the listing: says “modified 400 engine, VIN is H code, bored and stepped up at least one cam” (again: don’t beat me if what I’m saying makes no sense, just reading the words haha), Holley 570, msd ignition, edelbrock torker intake, headers (that have been ported) 727 torqueflite.

It seems as though the carb is a good place to start so I’ll see what I see

If the engine block is an original 400, it would have been cast between late 1971 and 1978. The 383 went out of production at the end of the 1971 model year. The engine block will have raised letters and numbers on it like so:

This is the right side of the engine, the passenger side. Circled in BLUE is where the engine size is cast. Above it is the date that it was cast. In this case, this 440 block was cast February 21st 1974.
Being an "H" code, that tells what the car originally had for an engine. It could be anything now. The numbers on the block will tell the story.

"Headers" are these things:

They are replacement upgrades for exhaust manifolds and are made from tubular steel. They do not get "ported" in most cases. What can be ported are the heads themselves....

 

[bcOH67]

‘This’ problem I guess would be the oil pressure dropping when I’m driving after a while. I guess I assumed it and the stalling when first starting up were related because they started happening at the same time. The other stuff I said was just info to maybe help inform a guess as to what could be going on.

Thanks for the pictures! I’ll look for the code on the block.

Spark plugs are new this year. No I just have one of those things you plug in to the cigarette lighter that tells the voltage. I did turn the idle speed down a bit fairly recently, but I drove for a couple months that way with no problem.

Like everyone has said though, I probably need to show my carb some love. So I’ll look at it and maybe find someone nearby who knows how to go over it.

 

[Lefty71]

found the listing: says “modified 400 engine, VIN is H code, bored and stepped up at least one cam” (again: don’t beat me if what I’m saying makes no sense, just reading the words haha), Holley 570, msd ignition, edelbrock torker intake, headers (that have been ported) 727 torqueflite

Now you are honing in on some useful info. Maybe even a pic or two would help.