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Help timing my truck

Putting the marks on the balancer with a Sharpie, Is how I have done it too.

Your problem has nothing to do with the fuel delivery system. The fuel is already in the bowl. Most stock-cammed engines will idle for two or more minutes on the fuel that is in the bowl . So forget chasing filters and hoses for now.

But that fuel has to be fresh clear gas with no contaminants in it.
If your fuel is anything but clear, it is not fresh. At 115 measly psi, your engine is gonna demand fresh fuel. At 150psi, the engine will be a lil more tolerant. At 180psi, mine hardly cares.
If the fuel is yellow it will still work in an EFI car because the computer is gonna adjust the AFR and timing to work with it.
After yellow is orange. The EFI car will burn that too, but the power will be down because of pulled timing., and erroneous AFR readings. After orange she goes into pink and red.
RED IS SO BAD, it won't hardly light on your garage floor,and will sputter to death, while sending off puffs of black smoke.
Orange is only a lil better.
Your carbyed engine is more sensitive. It needs clear to slightly yellow.
Gasoline is made up of many many different kinds of molecules, some of which burn better than others. Those good ones are the fire starters, while the slow-burners come along for the ride. After a week in open air, the volatile fire-starters have evaporated, leaving you with some in-betweeners. By the third week those have evaporated as well, leaving you with the Orange and Pink laZy fatboys, that can't hardly get off the couch. When you slap the throttle, it takes time for them to get moving, and a bunch of 'em have heart-attacks before they ever get to the chamber, and of those that make it, most of 'em end up hiding. For every 10 you invited, maybe only 8 or 7 show up, and 3 end up hiding, leaving you with 4 lazyazz molecules to burn, and summa those are so fat they can't hardly walk, never mind scoot.
So, while. if you can get the engine started, it will idle. But the gas is just too lazy to respond to a slapped gas-pedal.
Do not say, your gas is fresh, until you have color-checked it. It has to be CLEAR.

Wiki says; Elevation Everett Wa is 82 ft.
why is this important? Cuz that is dense air. It does not make sense to me for your engine to have only 115psi, with a fresh valve job. Ima thinking the rings are done. Rings have a few jobs; one of them you know as making compression.
Another is to evacuate the chamber on the intake stroke.
Engines do not suck air in.
On the intake stroke,the falling pistons create a low-pressure area in the chamber, and air ALWAYS moves from a high-pressure area to a low pressure area.
The better your rings work, the easier and faster the atmosphere will fill the chambers with air, and the greater will be the air-density in the chamber when the intake closes.
On a running engine, that just "inhaled" mixture will have,HOPEFULLY, the right amount of fresh clear gas in it, so that when the spark lioghts it up, it will ALL OF IT burn asap, because the optimum point of energy transfer is fast coming up; and if the flame is lazy, it will end up still burning when the exhaust valve opens. When that happens, and if the manifold happens to have oxygen in it, or if the just burned slug brings oxygen with it, then the fire will continue in the exhaust manifold. But hang on... when that happens, the manifold comes under pressure. And if the pressure spike cannot get away, remember air always moves from a high pressure area to a low pressure area. So if the manifold ends up at a higher pressure, than another cylinder connected to the exhaust manifold,......... with it's exhaust valve open....then pow! this hot burning slug is taking the path of least resistance, and in she goes. If this chamber simultaneously also has the intake valve open,as it would oif it was on the overlap cycle, then POW! the fire gets into the intake manifold, and you get a backfire thru the carb. Flames often attending.
Ok I'll admit, on a stock cammed Chevy this would be a rare deal. But even a stock 318 cam has 20* of overlap at a specified 008 tappet rise, which is just the part that we know about........ but seat to seat, there is a lot more.
How did this scenario arise?
Well, it started with lazy gas, and ended with late ignition timing. And may have been exacerbated by a restrictive exhaust system.
I'm not saying this is your problem.
I am saying, that it can happen with old stale gas.

A far more likely scenario would be the accelerator pump-shot being lazy, late, too short, not atomized properly; or once again, stale gas.
Stale gas will not infuse the incoming rush of air with the right amount of combustible fuel.

And your 115 psi is not helping it.
If a cylinder goes lean, the fair and fuel molecules could be so far apart that transitioning from idle to open throttle, they just never find each other. The upcomong piston is supposed to squeeze them together, which is supposed to increase their temperature, to where the most freshest molecules are eager to begin burning. When the spark hits POW! they give it up. Which is supposed to start a controlled chain reaction amongst the fayboyz. That is the kind of gas the refineries are giving us these days. So if the early boyz don't light, or if they are jusy too far from the fayboyz, or just not excited enough about the whole affair; then the fire fizzless out and you get a misfire. Now.... all those unburned molecules are going where again? Hyup straight into the hot exhaust manifold .............. with predictable results.
How did this scenario arise?
That's hard to say exactly, it may have started with a lazy pumpshot, or a lazy transfer slot; but the lack of cylinder pressure just never brought the air and fuel close enough together in the end.

If I had this problem with known to be fresh and clear fuel
I would be doing a Leakdown test to see just how good the rings really are. I hate chasing my tail.

But if the LD shows good rings ( less than 4% leakage in my opinion, up to 10% by others on FABO, and for Performance, Smokey Yunich preaches 3 to 5% is good; 5 to 8% is toast), then I'd be checking the cam-timing. Since you have already done that,and are satisfied, then I'm going with the transfers and pumpshot. If you close the throttles too far, the transfers will get lazy. They could even dry right up. If the fuel level is too low, pullover will become difficult, and your idle wells will pull too much air in to the emulsion tubes. Pull-over is a term used to describe the fuel in the wells (idle and main) being pulled higher than the fuel-level in the bowl, up to the top of the idle-well and then over the top and cascading down to the discharge ports. Remember; the engine isn't sucking in the fuel, atmosphere is supposed to be pushing down on the fuel in the float bowl. The air coming in thru the bleeds at atmospheric pressure is moving to the low pressure in the chambers, and the fuel is coming along for the ride. If atmosphere cannot get into the bowls or airbleeds, all bets are off. If at idle, the throttles are closed too far, the inrushing air will go thru the transfer slots, above the throttles, and exit underneath, drying up the transfers. Then, at tip-in, there is no fuel there and a hesitation follows. The pump-shot is not designed to cover that, it is much too slow. So when you slap the throttle; first you get the hesitation, which is the engine trying to stall. Then the pumpshot comes along and trys to make it all better, but it's like putting a bandaid on a hemorrhaging artery, too little too late; and you get a full-fledged bog, or lean misfire, or even a backfire.. Worse if the gas is stale.

Gotta go, it's supper time, yay
 
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Putting the marks on the balancer with a Sharpie, Is how I have done it too.

Your problem has nothing to do with the fuel delivery system. The fuel is already in the bowl. Most stock-cammed engines will idle for two or more minutes on the fuel that is in the bowl . So forget chasing filters and hoses for now.

But that fuel has to be fresh clear gas with no contaminants in it.
If your fuel is anything but clear, it is not fresh. At 115 measly psi, your engine is gonna demand fresh fuel. At 150psi, the engine will be a lil more tolerant. At 180psi, mine hardly cares.
If the fuel is yellow it will still work in an EFI car because the computer is gonna adjust the AFR and timing to work with it.
After yellow is orange. The EFI car will burn that too, but the power will be down because of pulled timing., and erroneous AFR readings. After orange she goes into pink and red.
RED IS SO BAD, it won't hardly light on your garage floor,and will sputter to death, while sending off puffs of black smoke.
Orange is only a lil better.
Your carbyed engine is more sensitive. It needs clear to slightly yellow.
Gasoline is made up of many many different kinds of molecules, some of which burn better than others. Those good ones are the fire starters, while the slow-burners come along for the ride. After a week in open air, the volatile fire-starters have evaporated, leaving you with some in-betweeners. By the third week those have evaporated as well, leaving you with the Orange and Pink laZy fatboys, that can't hardly get off the couch. When you slap the throttle, it takes time for them to get moving, and a bunch of 'em have heart-attacks before they ever get to the chamber, and of those that make it, most of 'em end up hiding. For every 10 you invited, maybe only 8 or 7 show up, and 3 end up hiding, leaving you with 4 lazyazz molecules to burn, and summa those are so fat they can't hardly walk, never mind scoot.
So, while. if you can get the engine started, it will idle. But the gas is just too lazy to respond to a slapped gas-pedal.
Do not say, your gas is fresh, until you have color-checked it. It has to be CLEAR.



Wiki says; Elevation Everett Wa is 82 ft.
why is this important? Cuz that is dense air. I t does not make sense to me for your engine to have only 115psi.



more coming

I'm at the highest point in Everett. Not so high as to make a difference, but 600 ft isn't 82 ft. That said, I get it, it's not the issue.

When I pulled the fuel filter yesterday, fuel ran clear and colorless (sorry, I minored in Chemistry, clear and colorless are very different). Now, I wasn't really inspecting for color so taking a more thorough look with white paper behind the gas in a clear, colorless container is worth both minutes it'll take.

I was thinking that pulling the carb apart and cleaning it is probably worth a shot! I know I bought the carb used. I know it wasn't used much. I know it was rejetted, leaner, by Edelbrock because the original owner was trying to get better fuel economy (I have the jets and the one spring Edelbrock switched out so I can return it to factory settings if I can figure out which spring was changed). But I have no idea how long it sat on a shelf with fuel rotting in the bowls. I know I emptied it as best I could when I pulled it off to do the heads. Those little passage ways, especially through the venturis, I'm sure clog up pretty easy. I think pulling it apart and giving it a good scrub and inspection is not only the next logical step, but the only thing I haven't tried! There isn't much gas in the tank, intentionally, so I'll probably just toss it and get some fresh stuff.
 
Carb is cleaned. Fuel was clear and colorless. I was expecting a hint of yellow at least but it had as much color as glass of fresh, bottled water. I still sprayed carb cleaner through every port and venturi to make sure they weren't plugged. Floats needed adjustment, so I took care of that adjusting per the Edelbrock manual.

I'd put the carb back on and test it but those stupid little retainer clips, well, I know where 1 of the 3 are. The other two are on the floor and I can't find 'em. I'll go get a couple more tomorrow. Woops.

I was also just doing some reading. I may have missed a step on the compression test. Not sure what difference it makes, but I missed it. While I did warm up the engine, I did NOT open the throttle. Once I get the carb back on, I'll retest the compression...correctly. I suspect, realizing my error, that my compression will be at least a bit closer to that 150 mark. With zero experience on this comparison I have no clue how much closer, but everything I've read tells me it's gonna go up when I do it correctly.

Btw, did I mention that I even rechecked that I had the plug wires in the correct firing order? Yeah, I'm pretty good at missing steps sometimes.
 
Used e-clips, they seem to work fine. Got things running. Have initial timing set to about 20* advanced and moved the accelerator pump to the hole nearest the carb body. I had it running well enough that I took it for a little spin! Still some hesitation at full throttle and the pedal feel is absolute garbage, but, if the transfer station were open, I'd be taking a load of yard waste today! It's not perfect, far from it, but it is kinda driveable.

Now that it's warm, I need to go rerun the compression test!
 
Well, the updated compression test is more similar than my crossed fingers hoped for. Low at #1 at 115psi. High at #3 at 130 psi. Everybody else at 120psi.

Checked spark plug gaps while they were out. One was close to .040, one was about zero (but I dropped it before measuring), the rest were at .035 (I believe that's where they should be).

How sensitive to plug brand are these engines? I know Autolite isn't the greatest plug ever made, but is it good enough that this thing should be running better? Autolite 65 is what Napa sold me. They're pretty carboned up, but with mostly idling I'm not sure that's surprising. While a hotter plug would help at idling, is it worth the bother to switch?
 
When you do a compression test, you know that you have to keep on cranking until the highest number is achieved at least twice,on the same cylinder..... right.
The open/ closed throttle is no big deal; it just takes a couple of extra revolutions to reach max. Unless, unless, unless; your throttle is so far closed that fuel finds it's way into the chambers and washes off the oil-film; then your psi tanks.
But, the battery has to have adequate power for the entire test. If cranking speed falters, so will the numbers. For this reason I always do a 9th hole, the same as the first, to verify the cranking speed had not fallen.

20* idle timing is way too much for a stock cammed engine for two reasons;
1) the power-timing will be waaaay to high, and
2) the transfer slot will be waaay too far closed at idle
As to #1;
the power timing must be less than the detonation limit of your fuel or 36* whichever is less. Idle timing is of no serious consequence.
So to set your power-timing, you rev it up while watching the timing mark on the balancer. And you keep on reving it up until the distributor no longer advances. This may take 4000 or more rpm. This number should be no more than 36*, and can be less if the engine suffers from detonation. If this results in idle-timing of close to zero, This requires taking apart the D and changing the slot length.
As to #2;
setting the transfer slot; remove the carb. Make sure the throttle valves are NOT on the fast idle cam, and stay off it. Flip it over and eyeball the transfer slots ; these are the two vertical slots in the front of the primaries, one in each barrel. These need to be square to slightly taller than wide. I'll guess that on yours they should be square. To change the slot length, you use the curb-idle screw. Make them so, and then leave them there. If your idle speed is not 550 to 650 in gear for a stock cam, you change it with idle-timing; NOT with the speed screw; leave that one alone.
If you change the idle timing, that will mess up your power-timing. You have to fix that. This requires taking apart the D and changing the slot length.


When the tune is right and the ignition system is more than adequate; then the engine will not care about what brand plug is in it. A good coil will spark .045 no problem, and makes the spark hotter than .035.. Most coils will have no problem with .045 at idle. If the coil is weak, it will drop sparks when under load, as in flooring it in too low a gear or at too low an rpm.
.035 is a normal gap for a Mopar.
 
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I cranked each cylinder until max pressure showed on dial. I think it took 5 or 6 cranks (ish) on each cylinder.

The '9th' cylinder is a good idea, I'll try to remember that next time. Battery appears strong, starter is brand new. (Heck, everything but the bottom end is brand new.)

I'm heading to the truck now to pull the carb and check this. I spent a bunch of time last night looking for pictures of it since I didn't have a clear idea of what was going on. I did check this when the carb was off, but I don't think I was looking at the right thing. I'll post pictures while I'm doing it so if somebody else isn't clear, this will be one more place to hopefully clarify.

I may widen the spark plug gap too. A little hotter gap, I imagine, wouldn't hurt anything! Plus, it's only a few minutes of effort. But I'll do the carb and plugs separate so as to only change one variable at a time.
 
Forgive the less than stellar photos. It appears that the Edelbrock 1406 isn't capable of blocking the transfer slots. It won't even go square. I got them a little more square than they were, but they're still pretty rectangular.

The top photo is supposed to be showing the screw, I think you called the curb idle? I don't see this screw in the manual. The fast idle screw, the one I can easily access with the carb still mounted, isn't touching anything. I even pulled the rod connecting the accelerator pump off as that seemed to be limiting the movement of those butterflies.

The lower photo is supposed to be showing the transfer slot itself in this minimum point of adjustment. They're, roughly, two or three times taller than they are wide. Again, that's as close to square as this carb will allow me to get them.

IMG_0917.jpg
IMG_0916.jpg
 
The throttles should be able to close all the way; you need to fix this!
The problem could be;
the fast idle cam,or
the accelerator pump adjustment,or
the secondary linkrod.
the throttles must close all the way; do whatever it takes.

Sometimes the throttle valves are not properly set in the throttle shafts and one of them is hanging up on the throttle bore; this too has to be fixed. But before you go there, make darn sure it ain't one of the easy ones already mentioned. You gotta fix this or it is highly unlikely that you can get your idle fueling right. Lots of guys get fooled by some piece of linkage or another.

Your engine idles on a combination of fuel being delivered from the transfers and from the idle mixture screws. This also affects the low speed fueling.
It is possible to trim the mixture screws lean for a too-far open transfer slot and have a great idle. But as soon as you tip in the throttle, the total mixture is lean, and you are likely to have a hesitation.
It is also possible to trim the mixture screws rich to compensate for not enough transfer fuel; and now the total low-speed circuit is rich all the time, and the gaspedal may feel sluggish.
These two have to be synchronized with the idle and low-speed timing, to all work together.
Your engine should like idle timing well into the 20s , depending on the idlespeed. That doesn't make it right to give it that much; for at least two reasons; 1) it screws up the transfer slot exposure, and 2) who cares about idle timing; the engine has a fluid coupling, that allows the rpm to increase to stall speed almost instantly with throttle application, and THAT is when the timing becomes important, but at idle, all you want is freedom from sags and hesitations and plug fouling.
Try it sometime; just crank in some advance until the rpm no longer rises, then check your timing. When it stops climbing,that is the most efficient timing for that rpm and loading. But if you try to run it like then by the time you hit second gear, I can almost guarantee detonation, because the timing will be all messed up for the new rpm and loading.

As to the plug gaps, leave them where they are for now. You can fine tune some other time. Lets just concentrate on getting this thing to take throttle.
 
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I'd go try exactly that, but it's hailing. I think I'm done for the day. :)

I did do a couple of things thinking I was stuck where I was. I put the larger secondary jets that came with the carb (I believe these are original, but who knows) back in and pulled the smaller ones (398 were in the bowls and 401 now in the bowl). I also replaced the springs for the metering rods with the softer, presumably original, ones. I didn't like that change so undid it. But the bigger jet seemed to make things a bit happier.

I also took some timing out of it. Timing stops advancing now somewhere around 22* so I have some room to add.

But, based on what you've just said, I have some more work to do when the hail stops. Better weather is in the forecast.
 
Don't get the Idle-speed screw or curb-idle screw
confused with the fast idle screw,
The curb is on the drivers side.
the fast idle is on the passenger side.
To check the t-port, the fast-idle cam must not be engaged!
 
Try not to get ahead of yourself.
The idle and low-speed circuit together with the idle and low-speed timing, have to be sorted out first. I often completely disable the secondaries, so they cannot interfere.

I also took some timing out of it. Timing stops advancing now somewhere around 22* so I have some room to add.
I'm not understanding this.
When quoting timing is should be accompanied with an rpm, and a starting point.
Like;
my D has 22* of mechanical timing in it,
When I set the idle-timing to 12*@650 rpm, then it will have 34 at 3400 rpm, not including the Vcan timing.
That there is a swell statement; Including all the parameters.


ut if 22* is all you get from TDC, well that's a big problem.
 
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Don't get the Idle-speed screw or curb-idle screw
confused with the fast idle screw,
The curb is on the drivers side.
the fast idle is on the passenger side.
To check the t-port, the fast-idle cam must not be engaged!


There are no screws on the passenger side, except the body for the electronic choke and the screws to adjust that.

On the driver's side there is a fast idle adjuster where the screw head points towards the front of the car, basically parallel with the ground.

Below that screw, on an adjacent fixture, is a screw where the head is pointing, roughly, towards the bottom of the core support, maybe a little lower. This screw, when adjusted, clearly moves the primary blades. It wasn't much before they hit the bore, but it did move them. I think it's plausible to adjust this without removing the carb, but it wouldn't be easy.

The fast idle screw, was (it's been adjusted since) WAY out so as not to interfere. I also pulled all three linkage rods that would interfere with the primary throttle valves. One goes to the accelerator pump, one is for the choke, and one I think connects to the secondaries? There are only three, I think I'm recalling their locations correctly.

I still need a tach so I still can't give you rpm details.
 
OK gotcha with the electric choke;
but the bottom line is still the same; the valves have to close all the way, by backing out the speed screw.
I have never seen a carb on a Mopar, that could not be closed all the way; don't forget the secondary link rod; it may have to be rebent; that is why it has a 90* bend in it.
 
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Managed to square the transfer slot. It took some serious tweaking, but I got it. It didn't seem to help anything.

Thought I had found a tach. Turns out I had bought a multi-meter from HF that had a tach on it. Pretty sure my engine wasn't running at 150rpm. Guessing closer to 600 to 800.

I did mess with the timing as best I could without a tach. Initial, at an idle that 'sounds' reasonable is at about 7*BTDC. WOT, with vac advance, maxes out at about 34*BTDC. Still stumbles when throttle is slammed. It doesn't backfire anymore though.

Still need to add some gap to the plugs. I'll clean up when I do. Maybe that'll help.
 
I did mess with the timing as best I could without a tach. Initial, at an idle that 'sounds' reasonable is at about 7*BTDC. WOT, with vac advance, maxes out at about 34*BTDC. Still stumbles when throttle is slammed. It doesn't backfire anymore though.
WOT power timing is done without, without, without vacuum advance; as is the idle-timing; as are all timings.The Vcan timing is never considered part of the timing. It is purely a PartThrottle device to dole out advance in accordance to the load, to increase PT Torque, which helps increase PT fuel-economy.
If you really have only a maximum of 34* of advance at PT, with the Vcan hooked up, then you better prove it actually works.
 
I spent a lot of time reading up last and just tested things. So, yes, there's more timing in it now without vacuum advance, about 36*. With vacuum advance it's well over 40 (I didn't add any more marks on the balancer so don't have an exact number). Here's what I couldn't find in my reading...

If it's bad to have more than about 38* of timing in the engine for fear of detonation, now, at WOT, with the vacuum advance, I have well over 40* of advance. How is that safe for the engine? Granted, I'm not hearing any pinging, but I was pretty sure an engine doesn't play nicely with TOO much advance.

Also, it still bogs with 36* advance without the vacuum advance and over 40* advance with it.
 
Charm, yur not listening.
The vacuum advance does not work at WOT, there is not enough manifold vacuum to make it work.
And it MUST not work at idle. Because as soon as you step on the pedal, the vacuum will drop out, and your timing will go retarded.
That device must only work at Part Throttle, while the car is moving.
Your Power Timing is a WOT timing number; that is WideOpenThrottle,WOT, and it should be whatever the engine wants, between 30 to 38 degrees, but less than detonation. If it detonates at 30 degrees at 3000 rpm, them that is too much. If it stops detonating at 3600 with that same 30* then you have to delay your 30* to 3600. If now, it accepts 32 or 34, then you give it to her, as long as it doesn't detonate. Sometimes you have to delay it to 3600 or 3800, it all depends on your engine, and the parts that make the combo.
Finally, As to WOT;
Don't go looking for the perfect number today. Your butt dyno will not be able to tell the difference of 3 or 4 degrees in first gear, unless it is detonating. In second gear,under 60 mph,depending on the rpm, you probably won't feel it either. The point is that if you cannot feel it, then there is no point in risking the engine if you cand hear see or feel detonation. You can fine tune it after you get you get your tip-in figured out. Just make sure the timing does not come all-in too soon.

If you don't have a dial-back timing light,and if your damper is not graduated, then order yourself a timing tape and stick it on the balancer, so you can see exactly what is going on.
Also, it still bogs with 36* advance without the vacuum advance and over 40* advance with it.
yur not helping me;
Is that 36* at idle, or at 1000rpm or 2, 3 or 4000?
At what rpm is it bogging? Is the vehicle moving? At what speed? Does that truck have an automatic ? What is the stall speed? or the rear gear ratio? What tire diameter?
What is your idle speed drop when you put it into gear?
Some combos just will not work.
 
You know what would help, is if you could list all your pertinent info, in your signature, so it appears on the bottom of every single post.
To do that go to the top of any page and find your name on the Top RH corner, clik on it and go down to "signature", then clik on that. Down will drop a menu for you to type in a message. You get about five lines worth. If your message gets to be too long, then when you post it, it will tell you so, and then you start trimming content. Check out my new sig below.
 
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