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Gauge issues and Vacuum leak (2 problems)

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blue78

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Dec 28, 2014
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112
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Hi, well it does look like the ignition timing is off.
The standard Ford factory would have the vacuum advance cannister in front of the engine and the rotor pointing more or less at 1:00, towards the master cylinder.
I would bring the mark on the balancer up to # 1 tdc and see where you are at.
If the picture is #1 tdc, that explains why the distributor is twisted clock wise so much.
I would probably gently lift the distributor and turn the rotor counterclockwise 1 tooth ( maybe 2) and see if the rotor lands at 1:00 o'clock with the timing marks lined up and the vacuum advance cannister in front.
Also make sure the firing order corresponds with a Ford diagram, with the rotor pointing right at the #1 wire on the cap. It is a good idea to mark the distributor body with a sharpie where the #1 wire on the cap is so you can easily see the spot with the cap off.
Good luck

Plot twist. So that pic is taken from the top side over the brake booster, that blue mark on the body of the dizzy is #1 and is pointing damn near at the camera.

Here is where it gets interesting. I realized that the motor was cold the night before when it went into gear so this morning I did a cold start and boom, right into gear. Here is where I need the experts the weigh in, it will idle in gear for about 20 seconds then die. I have uploaded a video

https://youtu.be/fS1mHmEB-5s

Now I am thinking it is an expansion issue. I talked to the motor builder and he is still preaching timing so I am going to bump it up to about 14 degrees and see what happens but my next step is to go to a set of .120 head gaskets since the last two sets have been .060. If that doesn't solve it then I'm going to start looking at a new set of heads because I am running out of ides.

What say you, experts?

Kyle
 

B RON CO

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Hi, I don't think the stalling has to do with the intake or gaskets.
The way it just stops makes me think you are losing spark. If you were losing fuel it would probably sputter. I would put a spark tester on it and see if you lose spark.
What kind of carb is that?
What happens if you raise the idle?
What kind of ignition? I
If you have a tach, disconnect it until you figure this out.
Good luck
 

DirtDonk

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I didn't read the last few posts slowly or in detail, but will go back once I get this out and onto the screen.
It does not matter where the distributor points, OR how many teeth on the gears it is on or off from "normal" in any way. This is because "ignition timing, is ignition timing" period.
In other words, if your marks and pointer are correct, and your timing light shows 10° BTDC, then your ignition timing is, in fact, at an accurate 10° BTDC

The only thing that changes in that scenario is where the distributor is pointing when at that particular timing advance setting. But the advance setting per the light, is what it is. What you see is what you get always.

You can point your distributor body 30, 90, 150, 180 degrees out, and as long as the rotor is pointing at the number 1 cylinder wire terminal when the number 1 cylinder is where it's supposed to be, your timing is correct no matter where anything external is aimed.
The fact that there is a #1 often molded into the cap is simply for efficiency and visual clues and so that most pre-made wire sets will fit. There is no etched-in-stone rule that says your #1 plug wire has to be where they normally are. Nor does your vacuum advance can have to be pointed in a certain direction for timing to be correct either. That is also just for efficiency and the widest range of adjustment once installed, due to so much crap being in the area that you can't spin a distributor 360 degrees. In some engine combinations, you can barely turn the distributor body 20 degrees before you hit something.
If yours is positioned in such a way that you are able to turn it to adjust the timing enough to keep it tuned up properly, it's ok to leave it there.

So timing is timing. If your distributor happens to be pointed the same way as 90% of the others, great. But if not, your timing light does not lie.
Well, unless your marks are off.%) But as we know, that's a whole 'nother can-o-worms.

Paul
 

DirtDonk

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On the temperature front, another thing that is happening is that your choke would be naturally opening up as well.
Perhaps it's a case of running so lean that it will run when the choke is held closed (mostly) but start to lose it's oomph when the choke starts to open and the mixture leans out.

By the way, what the heck is that big honkin' Gilmer belt doing on the front of your engine? What don't we (or I, if I wasn't paying attention to something) know about this engine?

Before, when you were spraying the starting fluid, is there any chance that some was getting sucked straight into the carburetor? Is that a Demon by the way?
It doesn't look like it, but I wondered about the the second time I watched the first video.
And have you tried spraying in other areas?

I think the idea of checking the firing order is a good one, even though the engine seems to start and run way too well for it to be a mis-wired firing order. Still, it never hurts to quadruple-check that kind of thing.

Paul
 
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blue78

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On the temperature front, another thing that is happening is that your choke would be naturally opening up as well.
Perhaps it's a case of running so lean that it will run when the choke is held closed (mostly) but start to lose it's oomph when the choke starts to open and the mixture leans out.

By the way, what the heck is that big honkin' Gilmer belt doing on the front of your engine? What don't we (or I, if I wasn't paying attention to something) know about this engine?

Before, when you were spraying the starting fluid, is there any chance that some was getting sucked straight into the carburetor? Is that a Demon by the way?
It doesn't look like it, but I wondered about the the second time I watched the first video.
And have you tried spraying in other areas?

I think the idea of checking the firing order is a good one, even though the engine seems to start and run way too well for it to be a mis-wired firing order. Still, it never hurts to quadruple-check that kind of thing.

Paul

I didn't think about the choke, I'll pay attention to that tomorrow. I have a small cap HEI on there and my motor guy is sending me another one because he echos the spark issue. I checked the firing order several times but I will check it again because it never hurts.

When I was spraying the fluid before there was no chance it was getting in to that beautiful Demon carb. I was deliberate with the spray trying to isolate the issue.

I just read a Corvette forum where someone was having this issue and it turned out to be because the block was decked, wrong thickness of gaskets were used, and then the intake didn't line up properly. I may be grasping at straws at this point but that makes a lot of sense to me.

I'll try the new ignition that my guy is sending me and see if that fixes it before tearing into the motor any more, but I think the .120 gaskets are going to be a better avenue to go down.

As for that gilmer setup, there may be plans down the road to have something hanging out the top of the hood. For now we'll just say I sometime prefer form to function.

Kyle
 

DirtDonk

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I hear ya... Just making sure that thing was not somehow installed already and you somehow managed to photoshop it out of the picture!;D
Maybe hanging off the side, like the old Paxton even.

Anyway, definitely find out about the decking. It's a long-held bit of engine building trickery that you absolutely have to machine the intake manifold too, if you go over a certain amount on your decks and/or heads.
Even my 400, where the decking was minimum, was very difficult to match up without machining the intake. It appeared to be "close enough" to work, but it sure didn't make me feel good about it. The ends were too close to the China rails and the head mating surface looked like it was at a slight angle instead of parallel.

I don't suppose you were able to get your head in there and eyeball down the line to see how the parallelism was on yours by any chance?

Paul
 

DirtDonk

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Oh, and I'm sorry to say, I don't see how a new distributor can help anything. On the one hand, great for your builder to do that for you. No doubt about it.
But if your timing is set using a light, it's not going to change when you set it using the same light and the same knowledge and the same conditions with the new distributor.
Like I said, 10 degrees is still going to be 10 degrees.

Now, if the spark is somehow weak due to a poorly functioning magnetic trigger, or some other issue with the distributor, then sure, it can help. After all, better spark is a cure-all for many bad things!

I was not even aware you could get new thicker gaskets for the intake. That could be a good thing. But while you're messing about do some more idle tests with your can-o-whoop-ass starter fluid and see if you can determine if it's leaking all over the place, or just in one or two spots.
And a big enough leak like that was in the earlier video would certainly be lowering your vacuum gauge readings.

Paul
(still crossing fingers!)
 

Joe473

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Jul 16, 2012
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Oh, and I'm sorry to say, I don't see how a new distributor can help anything. On the one hand, great for your builder to do that for you. No doubt about it.
But if your timing is set using a light, it's not going to change when you set it using the same light and the same knowledge and the same conditions with the new distributor.
Like I said, 10 degrees is still going to be 10 degrees.

Now, if the spark is somehow weak due to a poorly functioning magnetic trigger, or some other issue with the distributor, then sure, it can help. After all, better spark is a cure-all for many bad things!

I was not even aware you could get new thicker gaskets for the intake. That could be a good thing. But while you're messing about do some more idle tests with your can-o-whoop-ass starter fluid and see if you can determine if it's leaking all over the place, or just in one or two spots.
And a big enough leak like that was in the earlier video would certainly be lowering your vacuum gauge readings.

Paul
(still crossing fingers!)
Sound like it's still a vacuum leak and / carb tuning timing. Where is vacuum advance hooked up. If direct manifold vacuum is it disconnect when setting timing? Choke coming off with vacuum leak makes it so lean any load kills it. Brake booster good? Also what are cam specs and torque converter specs? What does it idle like in park after warmed up? Can you do a cylinder balance test by pulling 1,plug wire at a time? Is this an adjustable valvtrain?

Go back to possible vacuum leak. When spraying put closed element air cleaner on carb. If u suspect intake still before putting back on lay it on heads dry with no gaskets and sealer. Make sure there is a slight gap on end rails when intake to head surface meets with no gasket. Use tight stuff and no endseals. Endseals may prevent intake from sealing. Also I would do ARP studs if aluminum intake.

Good luck

Sent from my SM-G900V using Tapatalk
 
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blue78

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Sound like it's still a vacuum leak and / carb tuning timing. Where is vacuum advance hooked up. If direct manifold vacuum is it disconnect when setting timing? Choke coming off with vacuum leak makes it so lean any load kills it. Brake booster good? Also what are cam specs and torque converter specs? What does it idle like in park after warmed up? Can you do a cylinder balance test by pulling 1,plug wire at a time? Is this an adjustable valvtrain?

Go back to possible vacuum leak. When spraying put closed element air cleaner on carb. If u suspect intake still before putting back on lay it on heads dry with no gaskets and sealer. Make sure there is a slight gap on end rails when intake to head surface meets with no gasket. Use tight stuff and no endseals. Endseals may prevent intake from sealing. Also I would do ARP studs if aluminum intake.

Good luck

Sent from my SM-G900V using Tapatalk

So I set the timing with the vacuum advance disconnected (coming from the base of the carb) at 14 degrees and it is still dying. I am going to throw in the new distributor just to confirm with my engine guy that I am not insane and this is a vacuum leak issue.

I didn't think about the end seals creating a gap issue. The builder originally used the blue RTV stuff and it still had this issue but next time I switch the intake seals I will use RTV too so it can squish down as needed.

I ordered the ARP studs so we'll see if that helps. I am just hoping that I don't have to pull the heads off and go with thicker gaskets there. IF I have to get the intake milled down I will just have to take this to a machine shop and hand them the reigns because I'm already out of my depth here.

Kyle
 

rmk57

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If your engine is a fresh rebuild sometimes if the block and heads are decked you can get a mismatch on the intake causing a vacuum leak.
If that is the problem then you may have to get the intake decked also. If the bolts for the intake are somewhat misaligned that may be the
problem.
 

B RON CO

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Hi, every mechanic should have an in line spark tester. It is a quick and easy test. I would check for spark before swapping distributors.
You may have mismatched ports and vacuum leaks but many engines run ( not OK) with that.
The way your engine cuts out on the video does not say vacuum leak to me.
Like I said before, if I was working on it I would turn up the idle because that will usually overcome a vacuum leak.
Good luck
 
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blue78

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I have the timing set to 14 and the idle at about 1000 RPM, I'm hesitant to go ant higher than that because I don't want it slamming into gear. I'll bump it up a little and see if it helps.

I usually just use a screw driver to test for spark but I guess it's time to grow up and get the right tools.
 

DirtDonk

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A timing light is easy to use for each plug wire to see if it's got a good spark traveling through it.
A spark tester would be good too, especially if it's small and fits into a tool box and doesn't require you to remove a plug wire like the old ones did.
If it's that type, I'd rather use a timing light.

Paul
 

Nicks501

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Following..... I have been fighting the exact same problem seems like. Can not find the problem yet.
 

B RON CO

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Hi, not being able to idle down is probably a vacuum leak. It could be the intake ports or something else, or both. Good luck
 
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blue78

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Update: I got a new distributor from my engine guy and dropped that in. I started it up to set the timing and it was running amazing. I put it in gear and sat and waited for it to die, but it didn't. After about a minute I thought this might have worked so I put it in reverse and rolled it out of the garage, it still kept running. Put it in drive and took off, went for a short run to the end of the block and back and then when I got home I slow down to get it in the drive way and it dies. I start it up, put it in gear and it dies. I start it again, give it a little rev and was able to get it back in the garage but it died as soon as I stopped.

I started it to check the timing and it was at damn near zero. I adjusted it up to 14 and put it in gear and it died. I started it again and sprayed it with the starter fluid at the manifold/head gasket and it died like in the first video. I am bummed but I will say that short drive made it all worth it to this point. This thing is going to cruise once I get this figured out.

Talked to the engine guy and he said set timing to 16-18, did that and it still died. I will give him a call tomorrow but I am still pinning my hopes on a set of .120 intake gaskets and manifold studs being the magic bullet.

I'll update as things develop, the gaskets should ship early next week.

Kyle
 

Nicks501

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so frustrating, like I said, I'm there with you. Have put on a new carburetor, re-routed gas lines, built a heat shield to keep any heat away from header on frame, adjusted timing, double-clamped all vacuum lines..... That has to be my next step also. Be curios to see if the gaskets help you. Best of Luck! Please update after you get it completed.
 
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blue78

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UPDATE: She Lives!!!!

I replaced the intake gaskets for a third time but this time I did things a little differently. I ordered a set of ARP intake studs and I think that was key. This made sure that the gasket didn't shift when I put the intake on. Also, I used some Permatex on the head side of the gasket, a very thin coat but it seems like it was enough.

I had ordered some .120 thickness gaskets but when they came in the port opening was way too big so I went with the .060 (normal) ones and sealed them. I have another set of .120 on backorder in case this fails again but now I know there is hope.

I got to take her out for a couple miles tonight and it was amazing. I'll finish test and tune and then I'll start buttoning everything up. Now that I can drive her a full build thread will be coming.

Kyle
 

DirtDonk

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Hey congrats! Nice to be able to drive it and feel the power, eh?;D
 
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