71 340 running bad

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Factory TQ intake? Did you try the 72 TQ? My neighbor found out not too many people know how to rebuild a carb anymore.
 
Yes factory 71 intake. Have not had a chance to try 72 carb
 
bballfan1 said:
The heads are new stock X heads.
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No such thing as new X heads. Obviously everything's not "good" as you have running issues. Saying everything is "new" means nothing as new and good don't mean the same thing.
 
RustyRatRod said:
No such thing as new X heads. Obviously everything's not "good" as you have running issues. Saying everything is "new" means nothing as new and good don't mean the same thing.
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Exactly. It is almost impossible to diagnose this over the phone. THese threads can go on forever with dozen's of hours spent posting suggestions. @bballfan1 you need to find someone local to you that knows their way around old cars.
 
toolmanmike said:
Exactly. It is almost impossible to diagnose this over the phone. THese threads can go on forever with dozen's of hours spent posting suggestions. @bballfan1 you need to find someone local to you that knows their way around old cars.
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I agree, especially after the hints to give more information have fallen on deaf ears. I don't understand it. If I needed help, I'd be splattering all the info I could on here. Like I always say. "My car runs great". lol
 
MOST guys here are very helpful. I've tr it Ed to describe problem. I had a locsl mopar guy at my house yesterday. He is very well respected. He is stumped!
 
Another thing to check as mentioned is floats.
Brass? they can leak and flood the engine.
Phenolic? they can get saturated and be too heavy, flooding engine.
Find the spec. you`ll have to weigh in grams.
 
bballfan1 said:
MOST guys here are very helpful. I've tr it Ed to describe problem. I had a locsl mopar guy at my house yesterday. He is very well respected. He is stumped!
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And this means what, exactly? Lemmie tell you somethin. Nobody here gets paid for helping anybody. You come on here askin for help, yet we have almost ZERO information. We've asked WHERE the timing is set. No response. We've asked WHERE camshaft timing is and if it was degreed. No response. We don't know what plugs you're running. What details about the engine. Induction, exhaust and so on. All we know is "everything is new" which is the stupidest thing ever and then YOU put a stupid little dig in to insinuate not everyone is being helpful? Here's an idea. How about YOU being helpful? You're the only one here who is not being helpful so far. Everyone here is ready to help you but we need some galddang answers, not just some bullshit "everything's new". Do you understand THAT?
 
my dad was a service manager at a plymouth dealer in the 70's ordered it over the counter. Engine sat for 48 years in dry storage, we took it apart to inspect. All factory marking were still inside the engine and it looked new.
 
The timing has to be around 50 or it won't run. I am not sure about cam timing or if it is degreed.
 
you need to find TDC on the balancer with a piston stop. Make SURE you are using the correct timing mark.
 
Everything is new, just did not get reassembled correctly after disassembly inspection.

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AJ/FormS said:
assuming all the vacuum ports are either employed or plugged, and that your secondaries are fully closed, that your brake-booster is not sucking air, that your PCV system is correctly plumbed and working properly, that there is no manifold vacuum in the crankcase, that the metering rods are staying down, and that you have proven your TDC mark is at least close;

At Idle, your engine will respond well to massive timing, just start it up, and without regard to the numbers, just pull in the timing as much as it likes. You will know that it is liking it by the fact that the idle speed just keeps going up. As you go, keep backing off the speed screw to keep the idle speed in check.
When you reach a point than additional timing does not produce additional rpm, stop and back up to the last adjustment that did. Now you can read the timing. If you have a Multi-strike ignition, you will need a compatible timing light.
If the number you get is greater than 90 degrees, you are on the wrong Plug-wire; back up/go forward, one cylinder in the firing order. Keep trying wires until you get one that reads about 25>35 degrees. Now yur on the right wire.
Do not drive it like this.
If you already are on the right wire, and getting a number in that range, then; shut the engine off, take the plugs out, and with the engine still hot, see if you can rotate the crank manually with a regular Johnson-bar.
If you find it to be extremely difficult, yur gonna have to figure out why and my guess would be that the ring gaps are too tight. To prove it rip the valve covers off, remove the valve gear, and try it again. With the gear off you no longer have to fight the valve springs, so if it still turns over real hard by hand, then sorry, I would be taking that engine apart. Another symptom of too tight rings at a normal timing of 14 to 18 degrees is that all that ring-friction tends to drive the engine into overheating or at least very high coolant temps.
While the gear is off, this is a good time to find split overlap, and see if it's at least close.

This happened to me. I added ~.004 to the top ring, and ~.002 to the second, and that was all it took. Yeah it was a PITA, but I was out of options. That engine got a whole new personality.
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a buddy of mine had the same problem with his brake booster. It was an NOS booster that just got old. Plug the intake feed to the booster and see what happens. Most of the time a zero vacuum is an intake leak or a port not plugged. Bad PCV valve? I had a warped intake cause this problem too. The should be easier to find since it’s a drastic problem. I would plug everything and go from there. By the way spraying the intake to find a leak doesn’t always work. Don’t forget to check any carb studs or bolts leading into the intake runners for leaks. All is good advise.
 
Just so you know;
I once had a 292/292/108 cam in my 367.
I retimed that cam from straight up to to 8* advanced and to 4* retarded, and she didn't much care about Idle-timing changes.
So I just gotta say this,
IMO;
if it idles, the stinking cam-timing is not your problem.
However;
every time I had an engine that wanted extreme advance to idle, the cam timing was severely retarded. But, in this configuration, it would not rev up either.
If it really wants 50* advance, and TDC has been prooved, to not stall, my guess is yur timing lite is on the wrong wire, AND the AND the ignition timing is retarded, both together.
Like I said earlier, just advance it till it idles decent, then figure it out.
BTW-1
the engine can be sucking air from the underside of the intake. You can test for this by flipping the PCV out. Sealing the CC, and plumbing a vacuum gauge to the dipstick tube. When you start it up, it should start building pressure, and you better not let it exceed 3>4 psi else the pressure may start blowing seals out. If you see vacuum on the gauge, Badaboom! that is bad, and the intake will have to come off.
BTW-2
I know you said the compression was good, but how do you know what good is? Good on a factory smog 318 is about 135psi at sealevel. But take it up to 5000 ft, and she'll be down around 110, which is still "good", on account of nothing but the elevation has changed.. and my 367 is really good at 195psi. So what the heck does "good" mean.
The reason I ask is because your engine can still run with the intake valves not sealing, and still make some pressure, it just won't be very excited about Idling, and especially not excited about starting up.
The best way of checking for this is by an LD test with the pistons at TDC on the compression stroke, no not all of them at the same time lol. If you get crappy numbers, relax the valve gear and repeat the test with the pistons at the bottom of their bores. This will differentiate between too tight a lash, and sticking or bent valves.
The thing is, when an engine sits for a long time, the valve stems may seize in the guides in an open position...... and then when the piston comes up and kisses them, they get bent. So then if your 340 is making 175 psi, which is really "good", this business is not something to worry about.
But if she is only making 140, which is better than "good" for a 318, well then, it is something to consider. But if just one is severely less than the best, well, you got a problem in that cylinder.
BTW-3
there is an easy way to check to see if your cam timing is at least in the ball-park, but your TDC mark has to be known to be accurate.
Just put #6 on TDC compression, verifying the mark.
remove the passenger-side valve cover, and remove the valve gear. Go to #6, and center the pushrods in the tunnels, front to back. Make sure the tappet cups are fully at the top of their strokes. Then just lay a small bar across the tops of the pushrods which should be level to nearly level, with the cam centerline. If it is not, just rotate the crank in whatever direction it takes to make it so; then read the balancer. Your window of correctness is, TDC to about 4 degrees advanced; but it will run, or can be adjusted to run, pretty good at up to 4 more degrees either way...... if the valves are all sealing.
BTW-4
if you have a carb with metering rods and very low idle vacuum, those rods will jump up, cuz they "think" the carb is at WOT, and thus could be richening up your idle-fuel. So look down into the primaries and if you see fuel on top of the throttle valves, you can bet this is happening.
For testing purposes just remove the springs that are under the little hats, to the left and right of the Primaries.

jus trying to be helpful.
 
How many times are u gonna have to be asked? What is the magic number?Supply us with some real world numbers. We can’t help u if u won’t help yourself and us. There is already 2 pages of guesses. I once had a pick up in the distributor cause this same problem. Check ohms on all ignition components. Are 5&7 wires crossed up? How many volts to the coil key on engine off and engine running? U have done excellent work on this whole build. Now do the same with this engine. To much preload can cause these issues.
Kim
 
oldkimmer said:
How many times are u gonna have to be asked? What is the magic number?Supply us with some real world numbers. We can’t help u if u won’t help yourself and us. There is already 2 pages of guesses. I once had a pick up in the distributor cause this same problem. Check ohms on all ignition components. Are 5&7 wires crossed up? How many volts to the coil key on engine off and engine running? U have done excellent work on this whole build. Now do the same with this engine. To much preload can cause these issues.
Kim
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How many licks does it take to get the center of a Tootsie Pop? The world may never know.
 
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