292 Questions

[RichardJ]

Adjusting point gap will change timing. Adjusting the timing should always be done after gap/dwell is set properly.

Set the dwell on the low side of the 31-34. As the rubbing block wears, the gap diminishes and the dwell grows. If you start with a dwell of 34* , after a few hundred miles of normal wear the dwell will grow to 36-37 and you don't want that. Starting at 30-31 and you don't have to go back in there for 10k-15k miles depending on point quality.

[Steeveedee]

If I am not mistaken, the vacuum advance moves the breaker plate so that the dwell changes some on the 292. You'd want to be certain that the vacuum advance is not connected when setting the point gap. Are you on the 6 cylinder setting of the dwell meter? Can you wiggle the distributor shaft from side to side by an appreciable amount? The bushings could be worn. This usually shows up as dwell wandering around while the engine is running.

[May70]

Originally Posted by Steeveedee

If I am not mistaken, the vacuum advance moves the breaker plate so that the dwell changes some on the 292. You'd want to be certain that the vacuum advance is not connected when setting the point gap. Are you on the 6 cylinder setting of the dwell meter? Can you wiggle the distributor shaft from side to side by an appreciable amount? The bushings could be worn. This usually shows up as dwell wandering around while the engine is running.

I made sure to cut off the vacuum. I have this plastic crimper tool for vacuum fuel lines and i just crimped that on there.

The carb vac port was reading about 22 in Hg on my gauge at idle. After all that I tried driving it in the back and thats when I couldnt get it past about 5, fiddled with adjustments a little bit but with no avail.

I tried backing out the idle screw till i saw a vac drop previously as recommended. However the vac reading didn't drop and that was with the screw backed out until I have the screw hanging on by a thread. Basically what I did from that point is screw it in a quarter turn, then get in the truck and see if studders from a little gas, eventually I got it decent. Vacuum was reading between 22-23 the whole process. Idles good, but once you start trying to get her up to speed it wants to do what I explained before.

//

I will drop that dwell a bit more based on that point Richard. Thanks

//

The distributor shaft seemed good. Not much wiggle at all, like very little if any. I can upload some pics here also, I thought the high points looked fine, but they weren't sharp points.

[RichardJ]

To check for shaft wear, remove vacuum source (as in other post) and rev engine up-down. Dwell should not vary more than 1-2 deg at most.
To check for point plate wear, operate vacuum canister with hand vacuum pump. Again, Dwell should not vary more than 1-2 deg at most. Dwell will vary some because the point plate doesn't rotate around the same axis as the dist shaft. The point plate rotates around a pin beside the shaft. Not the best design, but works well enough.

[RichardJ]

>>I tried backing out the idle screw till i saw a vac drop previously as recommended. However the vac reading didn't drop <<

IN.
Turn the mixture screw IN, CW, until the rpm starts to drop. Stay where it starts to drop and add 1/2 turn CCW.

[RichardJ]

You say you have the mixture screw hanging on by a single thread. That puts you clear on the right side of this graph. rpm's will only be a little lower, but the engine will be blubbering and running rough.
You are looking for an adjustment where the rpm's will drop off very sharply, but be patient. 1/2 turn at a time.

Engine warm, choke off, dwell and timing taken care of.

The screw may end up being 2 1/2 turns OUT from seated or 1 1/2 turns OUT. IT DOESN'T MATTER, as long as it responds to your adjustment.

If it doesn't respond to your adjustments until the needle is fully seated or even not then, you have a problem.

Make sure you don't have any vacuum leaks. Spray carb cleaner around the intake manifold and around base of carb. rpm's will vary if you spray at a vacuum leak.

[May70]

I have tried every place on the idle screw with no luck. It does the same thing. Idles fine, as soon as you want to get it more than a roll it drowns out. This carb has me beating my head against a wall.

The only response I get is when the screw is all the way in or within a half a turn from being seated, it wants to die out. The only difference I can tell between backing out a little more is when I get in the truck and try and go. Backing it out maybe 3 or 4 turns gets me to going up to a roll other than that there is no change. I set the float right at 1/4 inch as the manual said so I dont think the float is the problem.

I sprayed carb cleaner like you said. Idle increased when I sprayed the back side of the carb so I am not sure where it would be sucking that in at. I covered the whole intake manifold and it didnt do anything. Other than knowing now that the cleaner can get in some where in the back, not real sure how to narrow it down. Might get back there with the nozzle and spray a tiny bit on each gasket flange.

['68OrangeSunshine]

Originally Posted by RichardJ

>>Setting a points gap at .019 is just a starting point,<<

Not really.
A real gap of .019" should give a dwell of 31*, but the problem is that many people don't have a good sense of feel to actually get .019". It takes a soft tough and a perfectly straight alignment with the feeler gauge to get the right gap.
The movable point arm has a spring with only about 16 oz of pressure and can easily be pushed out of the way by the feeler gauge. This results in a narrower gap than you think you have and higher dwell reading.
It's best to use a feeler set that can be taken apart and use the single .019 strip.

>>pull the Vac line hose off the carb and plug it with a golf tee.<<

it is hard to stick a golf "T" into a metal vacuum port. Remove the hose from the vacuum canister and stick the "T" in the hose to stop any vacuum leak. If the carb is close to being adjusted correctly, there won't be any vacuum from a Ported Vacuum port, but it's best to plug it anyway.

The Vacuum line from my distributor to the carb is a ~1/4'' D. rubber hose. golf tee is perfect here. On stock applications, I guess there was a 1/8'' steel line, but my 292s have been modified since '78. Also with running HEI for the last 3 years, my points/dwell proceedures are rusty.
But it goes without saying, that you should make sure the breaker arm is at the highest angle on the six-sided block when adjusting points.

[geezer#99]

You have your float set at 1/4 inch but what’s your float drop set at?

[May70]

Originally Posted by geezer#99

You have your float set at 1/4 inch but what’s your float drop set at?

What does float drop mean? The 1/4 inch i am talking about is the 1/4 lower that the top of the float sits from flat, parallel with top of the flange

[geezer#99]

Float drop is the bottom end setting.
It’s how far the float drops.
If the float is too low the needle has a hard time controlling the incoming fuel. That can result in intermittent flooding.

[Mike_The_Grad]

Do you have a tach hooked up in your truck? If so, what is your fast idle rpm and curb idle rpm?(curb idle would be as if you were driving for long enough that your choke is fully open and you are idling at a stoplight.)
What was your vacuum gauge reading when you checked? Or do you still need to find a suitable vacuum source?
The info you provided about the engine sputtering wanting to die until you let off the gas pedal and it will idle seems to me like you are getting to much fuel and running rich. Can you pull the plugs and post pictures of them? Mainly concerned with the end that is inside the engine. Dont clean em or wipe em off, just pull them one at a time and snap a picture with good light so that you can see it clearly. If you were flooding the engine real bad for more than a short while, the plugs will appear dark and may even be wet with fuel. You could possibly end up with fuel in your oil if they are wet with fuel. A simple way to determine this is to pull the dipstick after it has sat for a while, like overnight, and smell the oil on the end. If you smell gas fumes or anything other than just oil, there's a cause for concern. If not, then you arent flooding the engine which is good.

Another item to check is your vacuum canister that is attached to your distributor. You want to be sure that the diaphragm inside of the canister isnt ruptured. This would cause a vacuum leak in addition to not functioning properly to advance your timing when it should be.
This happened to me. Took me a while to figure it out. And it happened by chance. I had my distributor apart because I was hunting down something weird going on with my engine. So I was systematically going through all of the possible things that could be causing my issue. Anyways, when I had the cap and rotor off I thought I might as well clean up the top of the distributor where the module and other parts are. When I pulled out the vacuum canister I wanted to know how the thing worked. So I tried moving the arm that is attached to the diaphragm inside of it. I realized it had some serious tension on it so I grabbed a screwdriver and used the shank to push in the arm, well about an ounce of the most varnished, rusted, and foul smelling gas shot out of the little nipple on the can across my work bench. I remember thinking to myself, "why is gas coming out of my distributor?" LOL. Well it was a result of multiple compounding issues I had at the same time. (That was a tough year for me. But I learned alot about my truck. ) also, the gas inside destroyed the diaphragm and ruptured it, creating a vacuum leak and not advancing my timing properly. Another reason it took so long to find is because people always say" Disconnect the distributor vacuum advance when adjusting timing." Which is 100% true. But, if you want to know your true timing at any one point along the rpm range, leave it connected. Then you are seeing how the engine is advancing based on rpms and vacuum. So, I say CHECK your timing with and without the distributor advance canister connected. But always ADJUST your timing with it disconnected and the source capped off.

[May70]

Originally Posted by geezer#99

Float drop is the bottom end setting.
It’s how far the float drops.
If the float is too low the needle has a hard time controlling the incoming fuel. That can result in intermittent flooding.

How do I adjust how low the float goes?

[geezer#99]

Not sure on a Monojet!
Every carb is different.
Did you find a spec sheet with your carb rebuild kit?
There’s likely a diagram on it with the setting.

[May70]

Originally Posted by geezer#99

Not sure on a Monojet!
Every carb is different.
Did you find a spec sheet with your carb rebuild kit?
There’s likely a diagram on it with the setting.

Hm I have the adjustment instructions in front of me and dont see anything with that. Only adjusting the float level

[geezer#99]

I dug out my ‘motors’ manual.
Seems I got you barking up the wrong tree!
My apologies!
No specs for float drop.
The carb design controls the drop. It’s firmly set with the top plate on.
Do you have a brass float? Or a black one?

[May70]

Originally Posted by geezer#99

I dug out my ‘motors’ manual.
Seems I got you barking up the wrong tree!
My apologies!
No specs for float drop.
The carb design controls the drop. It’s firmly set with the top plate on.
Do you have a brass float? Or a black one?

Black and its new with the carb kit.

[geezer#99]

Those are easy to break the seal where the metal contacts the float.
Your float will fill and sink.
What method did you use to adjust the float?

[May70]

I set the dwell to 31 degrees.

Timing is at 12 degrees of advance.

The oil does not smell like gas.

See pics of spark plugs. I just put these maybe 1.5 weeks ago and havent really driven it more than around the yard while Ive been working on it, starting it up, letting it idle etc. First two looked wet and pretty bad, the rest blackened but lessened as you can see in the pics toward the back cylinder.

When I first started it cold the rpm wass between 830-900 for the first ~ minute. After it warmed up it went up to 1050-1100 ish just at idle. This was with the fast idle cam on the fast idle notch and the mix screw 1.5 out. I couldn't get the rpm to change with adjusting the mix screw, so I adjusted the fast idle to get the rpms down to 700ish with the engine warm. I just came inside and read my pdf manual and it has a altered approach here:

L6 Engines • 20 and 30 Series
Manual Transmission
Disconnect and plug distributor vacuum line.
Turn mixture screws in until lightly contacting
seats, then back screws out four times.
Adjust Carburetor idle speed screw to obtain 600
rpm with manual transmission in neutral.
Adjust mixture screw in to obtain 550 rpm with
manual transmission in neutral.
Reconnect distributor vacuum line.


I figured I would try this...
I took that as put the mix screw out 4 rotations from seated. And adjust the fast idle screw again to get the 600 rpm. Im a little confused though because I only have two screws and hope I am getting this right. One mixture screw on the front and fast idle screw on the back side, as ive seen them called out. I then adjusted the mix screw in to get roughly 550 rpm and here is what happened:

Mix Screw Adjustment (Rotations out from seated), RPM, VAC (in Hg), Notes

4, 600, 20
3.5, 600, 20
3, 600, 20
2.5, 600, 20
2, 650, 21
1.5, 680, 21.5
1, 600, 20
.85 (estimated), 580, 20 ** Returned to this adjustment**
.75, 550, 18, Rough idle & vac dropped off jumping around 17-18


I checked the distributor vac canister. I dont have any hand pumps but I put a long vacuum line and a syringe on it with absolutely no change when putting a vacuum on it that way. I then took the syringe off because I wasn't sure if that was creating enough vacuum so I sucked on it as hard as i could and there was no change at all. I could blow into it and hear a little air whistling down at that canister. I also pinched the vac line and gave it a rev and nothing changed again. Dwell sat at 31 deg.

I sprayed carb cleaner on the back of the carb and it does ever so slightly increase the rpm. But I have to spray a lot to get it to do that so im having a real hard time narrowing down the location.

As geezer has mentioned my float might be sinking. It is brand new and I was very careful with it while adjusting the tang exactly how the carb instructions said. I will be pissed if that black float is leaking. I guess when I take the carb apart Ill check it in hot water.

[May70]

And spark plug #6...

['68OrangeSunshine]

Sounds like your vac can is shot. They're cheap. R&R the vacuum cannister with a fresh one and try that.

[May70]

I just went out and tried to do a cold start. Carb definitely doesn't like those adjustments. Wanted to die out when i first started it, seemed like no gas/not enough choke, when i gave it gas it felt like it was flooding out.

Ill go to the parts store tomorrow and have them order in the vac can. Looks simple enough to change other than the pin part, have to get a better look. Wonder if I could swap em out without taking distributor off

[geezer#99]

Have you thought of putting in an hei?

[May70]

I have been considering a pertronix kit with the coil and points delete. Somewhat pricey at the moment. Ive seen it about 110 ish plus shipping.

I was hoping to get this truck running decent enough to drive for a few months.

I think my next move is to pull the carb and just go through each adjustment again and check to make sure my float is good. I have no clue where the vac leak is. Getting really frustrating. Actually whats really frustrating is that before the carb kit, the vacuum break diaphragm was broke and it was super gummed up, yet it ran better than now.

[Steeveedee]

I wouldn't replace the vacuum advance canister until I had verified that it was leaking. That's dirt simple. If you have a vacuum pump/gauge you can pump that and see if you can pull a vacuum that lasts. Or, you can blow into the vacuum line, if you don't have the pump/gauge. If there is a constant flow, the diaphragm is ruptured.