Need help tuning Quickfuel carb

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I'll say this much, I can't recall seeing terminals with two marks on them. What's going on there? There should be one place where the rotor and the terminals are closest and thats were the electricity jumps. Usually its tip to side. In fact I just posted up pics of a rotor with a corner eroded away.
Here's the link Normal Cap & Rotor wear? - racingfuelsystems.myfunforum.org

Maybe talk to firecore. There should be one strike spot per terminal. This is worn but shows what I mean.

vertex-Cap-rotor-1-03-11-2018 22-17.JPG
 
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yeah the tan cap does look strange. PJC do you have a different distributor you can put in to test??
 
I don’t at the moment but I’m guessing the cap terminals showing that is because the rotor that firecore sends out in their distributors has a longer blade on it then a factory rotor.
But I’m back to thinking this is carburetor related after last night.
I waited till it got dark and I brought the rpm’s up to 2500 and held it there while I watched for spark scatter and I didn’t see any spark scatter.
But what I did see was my hedders glowing red while it was missing and running like crap.
So it’s obviously getting way too much fuel at 2500 rpm.
I don’t understand where it’s coming from when I’m running 65 main jets and a .036 high speed air bleed.
And .028 idle feed restrictors and .065 idle air bleeds.
Power valve is not blown, because I can kill the engine by turning in the idle mixture screws.
I don’t understand what’s going on here.
Maybe 65 main jets is just way too much for my engine.
I have some 0.45 high speed air bleeds I can throw on it to test and see if it clears up some.
I am at 3500 feet above sea level.
Timing has been verified, 18 initial and 34 total all in at 2500 rpm.
The timing mark on the balancer has been verified with a piston stop.
I’m ether way too rich or there is something going on with this carburetor.
 
It’s tough to say if it’s lean or rich without a wideband o2.
I really wish I had one right now, I’ve tried jetting down and that hasn’t done a dam thing.
I have not tried increasing the main jet, and it would only take a few minutes to
Pop the bowl off and install some bigger jets.
I have some 68s on hand no 70s though.
I would have thought being 3500 feet above sea level would require everything to be leaned out some.
This carburetor came with 68 main jets and I was told to drop down 1 size for every 1000 feet increase in elevation.
So I dropped down to 65s.
Maybe running 18 initial and 34 total all in at 2500 requires a lot more fuel?
I don’t understand what’s going on here at all.
All I know is all these parts are brand new and it’s pretty ridiculous that with all these brand new parts something could be running this bad.
 
put the 68 jets in and see if it acts better, remember, if it seems to run well and you keep the jets in. you need to reset your idle mixture screws (highest vacuum or highest rpm is good) after you drive it around to get heat in the motor and carb...
 
Well the main jets on this quickfuel carb don’t have anytning to do with the idle circuit.
The idle circuit is ran on the idle feed restrictors and the idle air bleeds and the 4 idle mixture screws.
The main circuit starts to come inn around 2400-2600 rpm.
It makes sense that it could be going lean on the mains and the missfiring that I’m hearing and feeling is a lean missfire.
I was just instructed by the person I bought the carburetor from to drop down to 65s because of the elevation.
But it’s possible he was wrong and the engine wants more fuel at those rpm’s for whatever reason, maybe it’s the amount of timing I’m running, and the quicker advance rate, i don’t really know.
Ive never tried running a larger jet in it so it’s worth a shot I guess.
It’s just confusing when you see people say glowing hedders is from too much fuel and other people say it’s from
Not enough fuel or not enough timing.
No one seems to agree on what causes it, you have guys that insist it’s lean conditions that’s cause that and guys that insist it’s rich conditions that cause it.
 
Glowing exhaust can be cause by several things. Rich isn't usually it. Usually. The number one reasons headers glow with no load is a slow timing curve. The air/fuel is lit so late, it's still burning after the exhaust opens, and the pipes glow red.


It's damn easy to kill a fresh engine with retarded timing. It will stick exhaust valves with .004 clearance.

No load rich conditions usually don't make the pipes glow red. They will blow black smoke long before they headers get red.


Time to post some good pictures of your spark plugs. You don't need a wide band to read plugs. You are so far off somewhere that Ray Charles could look at your plugs and get you closer.
 
I agree. I still think the rotor to terminal relationship is off and there's cross firing of some sort in there. Just because its happening under load doesn't mean its not ignition.
 
Are you suggesting rotor phasing?
Cause I’ve checked the rotor phasing with a hole drilled in the cap and it appears to be fine with and without vacuum advance.
Here is a pic of my plugs the last time I had them out.

57622592-3CA8-4C0C-81CE-7B7C25705D8F.png
 
Heres some help
Buzz the engine up to 2500 and set it there.
While it's revving, you can grab the distributor and twist it either way and observe the change in rpm.........and header temp. At 2500 the engine, in N/P ,is gonna want more than 45* advance, maybe closer to 50 or even 55. This is what the Vacuum advance can is for;to give her what she wants. If you don't light the fire soon enough,the still burning mixture will continue to burn in the headers.....and if it finds fresh air in there from a leaky header flange gasket, even more so.So if you already know about such a leak.......fix it now.
If this helps, and you don't have a Vcan, then stop the test and install one! If you do have one, prove it's working; they are adjustable.
Then retest. If this clears it up, then you may have to recurve the D for the operational Vcan.

But if you still have issues;
Get yourself a heat gun, and buzz the engine back up to 2500.
Let the temp in the headers stabilize. Then completely cover and SEAL the secondaries, like jam a rag in there. Note any change in rpm, and note any change in header temp. If this helps, then shut her down and fix the open secondaries. Then
Return the fast idle to 2500, and again note the header temp. Now start closing the choke,or covering the airhorn with a second bunched up shoprag; little by little. If the Rpm rises, continue until it stops, and note the header temp.
From this testing it should be easy to sort out an overly rich mixture from an overly lean one.
Also note that at 2500 and vehicle parked, the boosters should NOT be flowing. You can just reach in there and put a finger on each booster and it should make ZERO difference to the engine.
At 2500/vehicle not moving, the carb should still be on the transfers, she doesn't care what size MJ is in there.
But if you still have rich issues
then I suspect your Power Enrichment System is not shutting off properly.
OK so that's the best I got
 
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I’m just getting so irritated with this thing lol.
I’m going to put the Taylor wires back on it since it ran better with them.
I will put my modified cap back in double check rotor phasing to make sure it still looks good.
I do have a modified reluctor I can use to reposition the rotor if need be.
I’m also going to try it at 2500 with and without vacuum advance seenif that makes a difference at all.
Is it possible the little bushing the oil pump driveshaft rides in went out? And it’s causing the timing to bounce all over the place?
This engine doesn’t have many miles on it at all, it’s right at 30k miles.
 
pjc360 said:
I’m just getting so irritated with this thing lol.
I’m going to put the Taylor wires back on it since it ran better with them.
I will put my modified cap back in double check rotor phasing to make sure it still looks good.
I do have a modified reluctor I can use to reposition the rotor if need be.
I’m also going to try it at 2500 with and without vacuum advance seenif that makes a difference at all.
Is it possible the little bushing the oil pump driveshaft rides in went out? And it’s causing the timing to bounce all over the place?
This engine doesn’t have many miles on it at all, it’s right at 30k miles.
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Have you seen the timing bounce around?
The reluctor does not change the rotor position, that's the job of the D-cam.
As for the bushing; that would be extremely rare, and even if it was worn, it would only allow the reluctor gap to vary, by an extremely small amount. Certainly not enough to bounce the timing around
 
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pjc360 said:
I’m just getting so irritated with this thing lol.
I’m going to put the Taylor wires back on it since it ran better with them.
I will put my modified cap back in double check rotor phasing to make sure it still looks good.
I do have a modified reluctor I can use to reposition the rotor if need be.
I’m also going to try it at 2500 with and without vacuum advance seenif that makes a difference at all.
Is it possible the little bushing the oil pump driveshaft rides in went out? And it’s causing the timing to bounce all over the place?
This engine doesn’t have many miles on it at all, it’s right at 30k miles.
Click to expand...


If the timing is not steady, it's usually two things. Either the timing chain is loose or the distributor has too much play in the shaft. I shim my distributors so they have .010-015 movement up and down. And I run a collar on the shaft with ~.015 clearance.

Sounds like you have multiple issues.

Can we see a closer look at the plugs? I think you said you know the two cylinders it's missing on. That would be the two I'd want to see close up, and one that's not missing.
 
No I am not seeing the timing bounce around.
I was just asking because I have seen people online say the oil pump/ distributor driveshaft bushing inside the block can go out and cause issues.
This distributor doesn’t have any significant amount of movement at that shaft up or down or side to side.
I mean it’s brand new and doesn’t even have 500 miles of run time on it.
And yes the reluctor position will change the rotors position. Read this, this is the same modified reluctor I bought to change rotor position if need be.
http://board.moparts.org/ubbthreads/upload2/7532635-reluctorsheet.pdf
 
The rotor indexes to the cam, and the reluctor slips down onto the shaft. You can clock the reluctor anywhere you want to, it has no bearing on where the rotor points to.
But if you do reclock the reluctor then the timing will change. If you then put the timing back to where you started THAT will change the rotor relative to the cap. But moving the reluctor has nothing to do with the rotor; they are not connected.
This is called phasing the rotor, and you said you had already done this, so what would be the point of re-doing it.
There exists a pretty big window for the rotor to be in, it;s not that hard to be in it. This is why I told you to retard the timing 8* degrees and see what happens.
I'm trying to help you but you're sure making it hard.
 
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In sorry to tell you this but your wrong dude, moving the reluctors position does move the rotors position.
I’ve seen it with my own eyes.
 
Read through this thread and pay attention to rapidrobert.
This guy is pretty smart and he’s who informed me of rotor phasing on the Mopar style distributors.
It’s a post of mine pertaining to the same problem I’m still having.
And everyone thought ignition at first including myself.
You have to go to page 3 or 4 before the rotor phasing gets talked about.

Vibration at 2500 rpm | Moparts Question and Answer | Moparts Forums
 
pjc360 said:
Are you suggesting rotor phasing?
Click to expand...
No. I'm saying there must be a reason why there are two strike zones on every terminal and black (carbon?) on the rotor. Don't know enough info to pinpoint cause - effect. If that's carbon, and its tall enough, that could explain the top strike zone. Then the question is why.

It appears that the electricity may be finding a lower resistance path to ground than through the spark plug tips. If so, that's whats showing up as misfires. Again, why? Is it something in the cylinders that's making it difficult for the voltage to jump and initiate the current flow? or is it something in the delivery path?
 
pjc360 said:
MSD Digital 6 box, a crane cams lx91 coil
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There's always a chance, even with new parts, for problems. The MSD digitals were getting a bit of reputation for issues - probably resolved by now, but keep in the back of your mind.
If you know someone with a scope, particulaly with some experience looking at MSD CD waveforms, a lot of stuff can be seen. Of course it may be subtle or not visible without the load, but I suspect its will still show up.
If your not familiar with scope, heres a few intros
The-Art-of-Spark
Spark Burn Time
ignition_testing
 
he has has had a crane ignition box as well as an msd ignition box on the truck, same misfire with both boxes...
 
pretty sure in a thread on moparts he said the problem was worse when the temp was colder. my immediate thoughts, lean fuel mixture...
 
cookietruck said:
he has has had a crane ignition box as well as an msd ignition box on the truck, same misfire with both boxes...
Click to expand...
Thanks. Good. I missed that.
Scope still can be useful. You can see faults in triggering and how the burn goes down. But its just so rare to find guys with scopes I only mentioned it in case he does know of one.
 
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