Slant six Holley 2280 stalls when stopping

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Hideogumperjr

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I was posting to "Slant six 1920 stall" so to avoid confusion as I am using the 2280 I am creating a new thread.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(Sorry for long thread.)
At issue, slant six 225 rebuilt about 1k miles ago if that, I don't drive it far nor often. Car will not idle well, if I try to get it to 650 rpm it will run a bit then choke, dying. Hitting throttle will start the whole process over again.

It will run at 1200 rpm for long times, hasn't died at that rpm but is a bit rough idling.
if I hit the brakes hard when coming to a stop the engine seems to want to die also idle speed drops faster the harder I hit the brake.

Thanks to AJ and Rusty and DogDish, Killer6, Bewy, pishta, I have done many of the things suggested.

Here is info on car and the work done.
Holley 2280 rebuilt at time of rebuild about 8 years ago.

It has an Oregon Cam #819, intake and exhaust clearance is listed at .012. Valves adjusted there.

The fuel tank has no vent in the system. I traced it from the fuel filler and there is a small 1/8" or so pipe that runs "torturously" from the filler down the neck to the tank, when I look underneath, the pipe is hanging in the breeze no connection.

It has no PS so no brake booster.

It is a manual brake system.

It has an electronic distributor.

Car will diesel a bit when shutting off when warm.

Timing is set to 5BTDC right now, changing does not affect the stall, adv nor retard.

Replaced plugs last month. which were somewhat fuel fouled.

I installed a new electric choke.

Adjusted the floats to 9/32 and cleaned the bowl out as there was a bit of crap there. Took out the idle screws and blew out the idle circuits and others.

Replaced the funky PCV hose as it was collapsing when running. Does not collapse now.

Plugged off the carb vacuums ports including small ones on front.

I tried to check fuel pressure with my pressure/vacuum gauge. Tee'd into the fuel line with the tee supplied with my gauge but it is like an 1/8" tee and my fuel line is bigger. Tried to clamp it shut be it leaked and the plastic tee broke.

I also sprayed some starter fluid at the throttle bushing area and it would speed up leading me to believe the Holley is worn. (perhaps the gasket?)

Checked valve springs and push rods. All seem fine.

Not Done.
Unable to do pressure test to verify 4.5 psi, looking for a brass tee that will work, or does someone have another way to check?
 
AJ's post from yesterday sez:
Ok maybe this;
after the lash is reset;
you must do a compression test, and do it correctly by, at WOT, cranking until you get two consecutive same or similar numbers on every cylinder. The results must be even or close to even, between all cylinders. I like numbers over 140, but if the cam is not stock, the numbers may not be meaningful, other than they must be even and reasonably high, which to me would be over 125.
I would do a LeakDown test to prove the valves are sealing; But you the compression test will do for now.
Now;
(This part references the 1920 I believe.)
if you have a carb that looks like the one in post #7;
take the carb off, make sure the choke is off, then flip it upside down. Close the throttle completely with the speed screw. Then open it until the transfer slot is about square. If your cam is not stock, you can open it a tad further, say to a lil taller than wide. Flip it rightside up. Reset the mixture screw to 1.5 turns from lightly seated. Block ALL vacuum ports except the PCV and make sure that port is open.
After this, DO NOT Touch the speed screw again, until I tell you to.
Reinstall the carb, making sure the gasket is the correct one for both the intake and the carb. Pour some fuel, about 40/50cc into the float bowl thru the bowl-vent. Remove, or at least loosen, the gas cap.

Loosen the distributor hold down just enough so that you can rotate the distributor with some difficulty. If you still have points, set them to the factory spec (I forget what it was, guessing .019 or so).
Make sure the PCV system is working, including that the hose is rated for PCV and not collapsing under vacuum when it warms up.
Do not reconnect the Vacuum advance.
Ok
now, in a minute,
you are gonna start the engine and warm it up. If the intake is not sucking air somewhere, and if the valves are sealing, and if the ignition timing is close, and if the float level is correct and remains correct; then the engine will start right up and after a short warm up, it should idle in the ballpark.
If it doesn't;
and if the idlespeed is too slow, you will advance the timing until the idle speed is in the ballpark. If it will not speed up into the range of 550 to 600 in Neutral/Park; either the float level is very high and the carb is flooding, or the cam-timing is suspect.but
if the idlespeed is too high;
by only a couple of hundred rpm, you will retard the timing until the rpm settles down. But if the rpm us well over 800 rpm; the intake IS sucking air, or the carb is sending unauthorized air/fuel into the intake, or the cam-timing is suspect.
If the engine is hard to start after the fuel level is stabilized AND If you didn't do a LD test earlier, now is the time to do it...... because; If the exhaust valves are not sealing during cranking, the falling pistons on the intake stroke will suck air from the exhaust system, instead of air from the plenum. This air in the exhaust has no fuel in it so of course it will be hard to start.
It could happen that the valves are sealing but at the wrong time, so once again, that would point to wrong cam-timing.
As for ignition timing; the engine is not particularly fussy for timing during cranking, as long as it's not retarded or crazy-advanced. But the further it is from ideal, the more throttle it's gonna take to keep it running after it begins to fire. Retard is worse. But remember, I told you not to mess with the speed screw until I tell you to. and we ain't that far yet.

Ok, now you know what to expect and what to do if it don't do what you expect,lol;
so crank it up and fix the idle.Until you get the idle fixed don't bother putting it into gear and don't even think about driving it.
Your target rpm for neutral/park should be from 500/550 for a stock cam, to 700/750 for a big street-cam.

PS; I don't have specs on your cam. If you do, please post them up, so I can get an idea of where to go from here.

Oregon #819.
 
I am reviewing this all to go over again.

Bewy's post today:

Wanting to stall under braking sounds like fuel level in the carb is too high. So check float level, any binding, etc & condition of n/s. High fuel pressure will also raise fuel level.

Dang what a mess I seem to have created here! My apologies but wanted to fix the 1920 posting to avoid confusion for those with that problem.

Thanks for the patience. Now if I drank I would go get a nice couple shots of t-key-la.
 
Does the 2280 use a dashpot?? Dieseling usually means bad timing in combination with too high of an idle setting. Also, I'd look hard for any possible air leak issues on the carb or manifold.
 
Does the 2280 use a dashpot?? Dieseling usually means bad timing in combination with too high of an idle setting. Also, I'd look hard for any possible air leak issues on the carb or manifold.
Yes I am believing it does have a dashpot and timing has been 5 btdc and the idle as you can see if set pretty high so Im trying to get that down below 1k and find why it will just die after idling for a short while when set below 1k.
thanks, Lefty. From a lefty also.
 
Do you know the cam specs? Rough idle & high idle speed could be because of the cam: more duration &/or overlap. It might need a high idle speed.
 
....pushed the wrong button, wasn't finished! High idle speed promotes dieseling, so that could be the cause of the dieseling.
If idle vacuum is lower because of the new cam, it might be causing the PCV to oscillate. This causes rough/unstable idle & stalling. Try disconnecting the PCV & plugging the hose.
If the cam has increased duration, depending on how much, it is going to want more initial timing. This is very easy to check: with engine idling, loosen dist clamp & slowly turn dist CCW. If rpm increases & idle smooths out, it wants more timing.
 
Try tightening up the carburetor mounting fasteners to solve that leak. It's very likely not the throttle shaft. For those to leak, they have to be really BAD. Incoming air takes the path of least resistance. Coming in through the carburetor throat is a HEAP easier than coming in through the throttle shafts. Normally they will not leak unless they are floppin slam around.

That camshaft has 219* duration @ ,050" lift. Not Earth shattering, however, for a slant 6 that's a good bit larger than stock. That means it will want more initial timing. I would try pulling the initial timing up to 12* and see how it runs. If it's favorable and you get no spark knock (pinging) pull in a few more degrees like maybe to 15* and retest. Also, if you can get us a manifold vacuum reading both before and after you change the timing, that would be good. Lastly, did you degree the camshaft, or just line it up dot to dot? Lastly, put the vacuum gauge on it and adjust the air screw on the carburetor to achieve the highest reading. Do this in drive if it's an automatic. Parking braking on and wheels chocked of course. Try these things and report back.
 
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How many turns out from seated is the idle mixture screw?
 
thanks for the input. Ill check and yes cam was degreed at build time.
BTW it ran great for several years then I had overheating problems which I finally resolved a couple or three months ago.
I used the vacuum gauge to set the idle screws at around 17".
I have tightened the carb but perhaps should replace spacer and gasket. Anyone have a part # for these two parts?

Ill get back.
 
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So carb bolts were tight, but I removed it and the spacer and cut some gasket material to put both above and below the used spacer.
Fired it up and still cant get below 1k rpm.
Moving on to the other things.
BTW I am going to order a new flange gasket for the holley do I need to have carb gaskets also? FrainBried.
 
I was posting to "Slant six 1920 stall" so to avoid confusion as I am using the 2280 I am creating a new thread.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
(Sorry for long thread.)
At issue, slant six 225 rebuilt about 1k miles ago if that, I don't drive it far nor often. Car will not idle well, if I try to get it to 650 rpm it will run a bit then choke, dying. Hitting throttle will start the whole process over again.

It will run at 1200 rpm for long times, hasn't died at that rpm but is a bit rough idling.
if I hit the brakes hard when coming to a stop the engine seems to want to die also idle speed drops faster the harder I hit the brake.

Thanks to AJ and Rusty and DogDish, Killer6, Bewy, pishta, I have done many of the things suggested.

Here is info on car and the work done.
Holley 2280 rebuilt at time of rebuild about 8 years ago.

It has an Oregon Cam #819, intake and exhaust clearance is listed at .012. Valves adjusted there.

The fuel tank has no vent in the system. I traced it from the fuel filler and there is a small 1/8" or so pipe that runs "torturously" from the filler down the neck to the tank, when I look underneath, the pipe is hanging in the breeze no connection.

It has no PS so no brake booster.

It is a manual brake system.

It has an electronic distributor.

Car will diesel a bit when shutting off when warm.

Timing is set to 5BTDC right now, changing does not affect the stall, adv nor retard.

Replaced plugs last month. which were somewhat fuel fouled.

I installed a new electric choke.

Adjusted the floats to 9/32 and cleaned the bowl out as there was a bit of crap there. Took out the idle screws and blew out the idle circuits and others.

Replaced the funky PCV hose as it was collapsing when running. Does not collapse now.

Plugged off the carb vacuums ports including small ones on front.

I tried to check fuel pressure with my pressure/vacuum gauge. Tee'd into the fuel line with the tee supplied with my gauge but it is like an 1/8" tee and my fuel line is bigger. Tried to clamp it shut be it leaked and the plastic tee broke.

I also sprayed some starter fluid at the throttle bushing area and it would speed up leading me to believe the Holley is worn. (perhaps the gasket?)

Checked valve springs and push rods. All seem fine.

Not Done.
Unable to do pressure test to verify 4.5 psi, looking for a brass tee that will work, or does someone have another way to check?
Could be that the Idle mixture is set to rich.
I had the same problem on a 340
Set the idle screws with a vacuum gauge for the highest vacuum at idle, then adjust them in - lean- 1/4 to 1/2 turn.
Should cure the problem.
 
After I replaced the gaskets I adjusted the screws to 1.5 turns. Ill give that a try.
Any ideas to check fuel pressure other than a tee in the fuel line? Im looking for a brass tee to fit the fuel line and a vacuum gauge.
 
After I replaced the gaskets I adjusted the screws to 1.5 turns. Ill give that a try.
Any ideas to check fuel pressure other than a tee in the fuel line? Im looking for a brass tee to fit the fuel line and a vacuum gauge.
The only way to check fuel pressure is to tee the line.
What is your initial timing set at?
 
After I replaced the gaskets I adjusted the screws to 1.5 turns. Ill give that a try.
Any ideas to check fuel pressure other than a tee in the fuel line? Im looking for a brass tee to fit the fuel line and a vacuum gauge.
There is no set, exact number of turns That is right "off the bat". That is generally a good starting point to fine tune it from, with a tach and vacuum gauge once it is started and warmed up.
It's not a "open 'x' number of turns and forget it" deal. You put that carb on another engine and it will need (at least) slight adjustment from where it runs best on your engine.
On my 83 D250 (not a slant 6 but don't matter for the point of what I'm about to say) the original carb had plugs blocking the mixture screws when I got it. Upon the 1st tune up I drilled the plugs so I could access those mixture screws, and in order to get the best vacuum and tach reading I had to open both mixture screws "about" 3/4 turn each, from where they were set at the factory.
Ran much better after that. Where was it set initially? (How many turns from seated) Don't know, don't care. Where did it end up? Again don't know, don't care. It was where it needed to be to run it's best. I still have that carb even though the truck is gone (I eventually put a 4 bbl on it) but that original carb is a Holley 2280 very much like what you have.
 
Thanks for the replies. So timing is 5BTDC right now, I have tried it higher and lower. 12BTDC and TDC. No change.
I have tried using vacuum gauge to get highest value, ~17".
Engine still wants to take a dump if I go below 1k or so.
Wondering if I should get a replacement carb but I am not able to throw more money at it and as I have said, the arthritis in my back and hands are making it more difficult and less pleasurable to work on the old girl, consistently.
I would like to find someone in the area around Seattle that might have a carb I can at least swap to see if its all just in the carb. ;-)
 
Thanks for the tee info, knew it had to be that way so gotta go find a good tee to use to fit with the reducer to the vacuum gauge.
Ill try the timing and vacuum check RR mentioned and the other stuff this weekend. It has been cool here in PNW west side, sposed to be warmer this week.
 
So I asked about this carb up-thread, can anyone comment on it?

Premium Carburetor Type Carter BBD High Top For DODGE 273 318 5.2L V8 1972-1985 | eBay

Is there a way to have a carb checked out? It was rebuilt ~1000 miles ago and ran great for a number of years.

I have a BBD replica like that on my Dart. On Amazon there are a bajillion different brands that appear to be identical, probably all made in the same Chinese factory. Anyway, it seems to be a well-made replica of a Carter BBD. Of course there were many variations of BBD made by Carter, so maybe all those different brand names really are different. On mine in particular, I have had trouble getting the mixture to be rich enough with the throttle open, without it being too rich at idle/cruise. But I'm still playing with it, and it does offer a good bit of adjustability. One complaint: from the factory the bowl level was WAY low, but of course you would check that before you install it, unless you're as dumb as me. :)
 
Those chinese knock offs run great. Its a NEW CARB and they usually run great out of the box. If your throttle shaft is leaking, its done. It will test one way and then test another depending on where the shaft wants to settle ie. may test ok at idle but be leaking at 1/4 throttle, stuff lie that. I had a Nikki 2bbl that had a shaft leak and I could not get a low idle...1100 or nothing. bought an NOS and dropped it down to 650, dead solid. They just work.....

>>> if your shaft is leaking at the dead end (no linkage end) glue a toothpaste cap over the shaft end. It will cure a leaking shaft at that end. other side is most likely the bad one as all the pressure is over there.
 
Thanks for the replies. So timing is 5BTDC right now, I have tried it higher and lower. 12BTDC and TDC. No change.
I have tried using vacuum gauge to get highest value, ~17".
Engine still wants to take a dump if I go below 1k or so.
Wondering if I should get a replacement carb but I am not able to throw more money at it and as I have said, the arthritis in my back and hands are making it more difficult and less pleasurable to work on the old girl, consistently.
I would like to find someone in the area around Seattle that might have a carb I can at least swap to see if its all just in the carb. ;-)
I am not a slant expert but an old school engine is still an engine.
5* BTDC is to retarded
Unless this engine have been modified I would believe that 10-12 * BTDC would be in the range for a stock engine.
I doubt that your carb and/or fuel pressure is causing your issue.
Get your timing and carb set properly and go from there.
Look for vacuum leaks
What do the spark plugs look like? Post some pic's of them so we can see.
 
I was playing with timing a number of times, getting different opinions on the timing. I dropped it to 5 to see if this was a cause of the dieseling.
Spark plugs were replaced a little over a month ago, old ones looked to be fuel fouled less than 1k miles.
 
More timing, not less, should help dieseling. The dieseling is caused by high idle speeds. Get the speed down, D stops. More timing usually increases idle speed. But at the same time it makes the engine more efficient [ speed went up using same amount of A/F ]. Once the speed is up from more timing, try re-adjusting idle speed screw & mixture screws for lower idle speed.
 
Thanks, yeah. I retarded the timing to see if that would calm the dieseling from an advanced setting.

I went out to work on the car and increased the timing to around 10-12BTDC and dropping the idle below 1k, died. I had been noticing the sound of the carb and had noticed that I could see visible fuel as a fluid in the throat. It finally hit me to pay attention and I could see the fluid fuel only going down the passenger side throat and nothing visible on the driver side.

I pulled the top of the carb and looked at the jets, figuring I would sway them side for side or at least see if something was causing the visible fuel. I removed the passenger side jet and it looked fine, then when trying to remove the driver side jet it would not unscrew and I screwed the slot up.

I put it all back together and stated it up and check the carb and there was gas just gushing out so I must have screwed up the float level. Shut it down and said screw it and ordered the carb above.

I'll report on the experience when I get it all back together.
 
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