318 Runnin Rough...
 

74 charger 5.2 318 2bbl w/ 360 manifold.

I just recently had the Heads Rebuilt, got everything back together and yet it runs rough. I put it at TDC rotor button points down the middle. When I hold the choke closed it idles high and poorly when opened. Any ideas?

Sounds lean, back out your idle mixture screws 1/4 turn each until it smooths out. Should have your timing set with a light too. Can't do one and not the other.

I tried turning the mix screws all in and out but didn't phase the rough running. Got it timed at 0, a little btdc or after. & still Runs rough.

I'd be looking for a vacuum leak. GO!

Everything is plugged except for PCV, Brake Booster & Dizzy. Manifold, Heads, Valve train & covers torqued to specs.

Did you use the small port size 360 intake? If not I'll bet thats your problem...

Small port? What's the difference? I think my intake is the original that came with the car but the engine has been changed.

OK....If it was on there before and ran, you should be good to go....
And put about 12-16* of timing in it... That will make it much happier... :)

12-16 BEFORE TDC

What's difference between the 318 & 360 manifolds beside casting #'s? Wanna make sure Ive got the right gaskets on the manifold.

Could be a gasket issue or warped carb base

Is there any way to test the intake for leaks?

360 Manifolds came in 7/8"X 2" (Small) ports and also 1" X 2-3/16" (Large) Port Manifolds....
You can uncover a intake runner and not even be aware of it.....
:)

Put Vacuum on the crankcase... But that take toolage... :)

Would I need a micro tool to measure the intake ports?

My 1974 Charger SE Baby Blue White Top
VIN # = WP29K4A170230
Block Cast # Driver Side = 2532630 = (318)?
Head #'s = 2843675 = (318)?
Manifold # = 3698437 ?

I use a dial caliper if i'm not sure...

If the Manifold is a 360-4bbl as the cast suggest, do o need a Carb Adapter Plate for my 2bbl Holley Carb?
Do I need Manofold Gaskets for a 360 or 318?

The point of my post are that you cannot always assume, You have to check!
AS you have found, there are many avenues/combinations that are fitting.
Your listed manifold says it a 360-4 intake. you have found thats not to be so true. Yours is the 360-2 version if I understand you correctly.
As for the head port to intake manifold match. You needed to check that prier to assembly... But without the knowing, you can only assume you have installed the proper gasket set. I have just pointed out what I believe is the au-evious problem with all other operating systems being in good working order.

The only way to really know.. Is to open it and take a look... Or you just have to run on the assumption that it's put together rite.

as for the first part of the question... Yes... You would have to have a adapter to install a 2 barr. carb on a 4 barr. manifold... I think that goes without saying...But I think you already new that answer...

:)

I did. Sorry for the questions. I didnt think that they made a 360-2 intake, at least ot doesnt show up on the casting # sites. I bet I've got a manifold leak somewhere or om usin the wrong gaskets.

Nothing to be sorry for Robert..Your just trying to get your problem fixed :).. I am sorry if my words came across wrong or a little harsh... That's not my intention..
Ok... So lets figure the intake gasket is the correct one and no other problems there....

Have you taken a vacuum reading with a gauge? And did you try the 12-16* BTDC timing? Yet?
Also... Where you able to fix your choke problem?

Not yet, its been rainin cats & dogs here past few days. When u get manifokd gaskets, do they need to match the intake or the heads? When I looked at the carb base, its 2 holes with a point in the middle.

When I do them I check both side... You just never know at what point in the vehicles life one or the other has or might have been changed.
The uncovering is so slight that if you don't look for it you can easily miss it.
This can also be a problem when heads are milled or shaved too much and the intake is not cut to match... Or even if one or the other has been ported at some point.. But it is not uncommon for this area to be a problem...
Just making sure you feel positive about it NOT being the problem is the best thing..
:)

Don't get stuck on one idea. This could be wrong timing having you turn in the idle speed screw in so far that it's past the idle mixture circuit, things we can't see or here on our computer screens.

My best advise is to do as Bob said, when it stops raining be prepared with a vacuum gauge, timing light and tach (tach not essential).

Start it up check vacuum, and timing and record. Add some advance with vacuum advance canister disconnected and plugged. If rpm goes up reduce engine speed to as low as it will go and still run, record results and report back.

Any change with results will be the quickest way for anyone to help fine tune this and get you running smoothly.

I think I put the wrong gaskets on the manifold, hence runs badly. I originally thought it was a 360 instead its a 318 A

how do u know its a 318?

Cast # on the block says its a 318 poly, the heads were 318's too. The vin says it had a 360 2-bbl.

Where are you with this repair?

I've got spark again but can't keep it runnin. I've got power from the battery all the way to the coil. Set it at Tdc runs bout 1-3 secs, turn it 180 it backfires. Maybe old gas. Gonna try cleaning the carb with cleaner later.

Give it more advance by turning distributor counter clockwise.

Already tried, I inched it CW & CCW all the way and still doesn't want to run. Replaced the dizzy & ballast today and got spark again. Would a weak alternator cause it to not run? It's been on there 20yrs but did run before with it.