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PostPosted: Wed Jul 11, 2018 11:46 am 
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1 BBL (New)

Joined: Sat Jul 15, 2017 9:12 pm
Posts: 6
Location: SW PA
Car Model*: 1983 Dodge D150 pickup 225 \6 auto
1983 Dodge 1/2 ton pickup 225 slant 6 Holley 1945 1 bbl

The previous owner said he rebuilt the carb, but it started puking gas from the bowl gasket, so I rebuilt / replaced nearly everything in the fuel system. It ran great (for a \ 6 that is) for several thousand miles. It suddenly took a dump one day, close to home. I changed out the fuel pump under warranty. Still intermittent bad idle and fuel starvation issues.

So, I got another carb kit and a new float as I didn't replace it last time. I pulled the carb and opened it up. It had a bunch of black crap in it, which actually resembled mouse crap. What the hell is it and how did it get in the float bowl? :shock:

It turns out, somehow it sucked up a bunch of charcoal from the charcoal canister or pressure forced it in through the bowl vent. It is definitely from the charcoal can. It is actually still inside the hose right up to where it hooks to the bowl vent on the carb. I haven't determined why yet.

While rebuilding the carb this time around, I did find that the bowl vent valve was WAY out of adjustment. Not sure if that was part of the issue or not yet. The accelerator pump rod needed lengthened, too. Maybe the slight off-idle bog it had will be gone now.

I don't know how I missed those things before. Brain fart, I guess. That, and the rebuild kit instructions said the bowl vent valve wasn't adjustable, but it was. It was actually so far out of adjustment that the cover didn't go on over it without forcing it closed some. I don't think it ever completely closed either. :?

A problem it always had since I rebuilt the carb the first time was that with everything hooked as per the emission sticker under the hood, it would run like crap when the purge valve would open, so I just left the line to the purge valve unhooked/plugged.

The charcoal canister has the purge valve built in. I tore it apart, made sure the diaphragm was good and the valve opens when it is supplied vacuum.

The canister/purge valve assembly has four lines, three large and one small. They are marked too, so they are right. The large lines are: one going to the tank, one to the bowl vent, one to a vacuum source on the carb. The small line, which opens the purge valve, goes to a thermal switch, which then goes to ported vacuum on the carb. The big problem I've had since I rebuilt the carb and replaced all the vacuum lines was always when the purge valve opened, it would act like there was a huge vacuum leak in the canister. If I pinched off the large vacuum hose between the carb and canister, it would run normally.

Worse comes to worse, I'll leave the canister unhooked and run it without. It has antique plates, so emissions/inspection aren't an issue. I'd rather it be "right", though.

I know I rambled some and condensed several posts I made on another forum into one, but does this make sense? I could always try to snap a pic of the vacuum diagram.

BTW, semi related, it still has the "lean burn" system for the spark advance. It does NOT have a feedback carb. I will be ditching the lean burn trash for an earlier vacuum advance dizzy and the HEI upgrade that I read about here. After I get this mess figured out, that is.

Any advice will be appreciated.


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PostPosted: Wed Jul 11, 2018 12:30 pm 
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4 BBL ''Hyper-Pak''
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Joined: Tue Sep 28, 2010 7:55 am
Posts: 39
Location: Powhatan, Virginia
Car Model*:
Hi and welcome!

There's lot of folks here that can provide good advice...While we wait for them to post, I have some suggestions!

I think you have already found your problem...You need a new charcoal canister!

Since I own a 1971 Slant Six, I researched the 72 and newer system to understand how they work.

Check out this article that SlantSixDan has mentioned before click here

Thanks!
burg


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PostPosted: Wed Jul 11, 2018 12:35 pm 
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1 BBL (New)

Joined: Sat Jul 15, 2017 9:12 pm
Posts: 6
Location: SW PA
Car Model*: 1983 Dodge D150 pickup 225 \6 auto
burgmopar wrote:
Hi and welcome!

There's lot of folks here that can provide good advice...While we wait for them to post, I have some suggestions!

I think you have already found your problem...You need a new charcoal canister!

Since I own a 1971 Slant Six, I researched the 72 and newer system to understand how they work.

Check out this article that SlantSixDan has mentioned before click here

Thanks!
burg

Thanks. I'll give that a read.


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PostPosted: Wed Jul 11, 2018 7:24 pm 
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Turbo EFI

Joined: Wed Sep 17, 2008 6:48 pm
Posts: 2376
Location: Indianapolis
Car Model*:
New charcoal canisters are hard to find.
To stop or prevent bits of charcoal from the
canister getting into your carb,, an ez fix is
to get an in-line fuel filter that has hose nipples
on each end and insert the filter into the hose
running from the canister to the carb.


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PostPosted: Wed Jul 11, 2018 9:27 pm 
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1 BBL (New)

Joined: Sat Jul 15, 2017 9:12 pm
Posts: 6
Location: SW PA
Car Model*: 1983 Dodge D150 pickup 225 \6 auto
That article had one interesting bit of information. It said "The canister must be kept upright, with the ports at the top."

Mine is mounted horizontally. :roll: It looks factory, but with the way some things on the truck have been hacked in the past, it very well may not be. It is mounted to the inner fender, and I know the fender on that side was changed at some point. I really can't remember how the ones in the trucks in the junkyard were mounted.


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PostPosted: Thu Jul 12, 2018 11:47 am 
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Turbo Slant 6

Joined: Fri Apr 16, 2004 10:50 am
Posts: 647
Location: Stevensville, ON
Car Model*:
I'm surprised that you got charcoal in your carburetor as I wouldn't think that it would transported with air through the vent lines. Is there a possibility that the you've got percolation happening in your carburetor and the charcoal canister is saturated with liquid gasoline. See this video for what I mean:

Boiling Vapor Locking Gas In Carburetor Float Bowl

Intermittent bad idle and fuel starvation issues could also be a sign of vapor lock.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech


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PostPosted: Fri Jul 20, 2018 12:26 am 
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1 BBL (New)

Joined: Sat Jul 15, 2017 9:12 pm
Posts: 6
Location: SW PA
Car Model*: 1983 Dodge D150 pickup 225 \6 auto
FrankRaso wrote:
I'm surprised that you got charcoal in your carburetor as I wouldn't think that it would transported with air through the vent lines. Is there a possibility that the you've got percolation happening in your carburetor and the charcoal canister is saturated with liquid gasoline. See this video for what I mean:

Boiling Vapor Locking Gas In Carburetor Float Bowl

Intermittent bad idle and fuel starvation issues could also be a sign of vapor lock.

Nope, I am 110% positive that it was charcoal from the canister plugging up the carb. It you saw it, it would have been very obvious.

I cleaned and rebuilt the carb, and plugged the vacuum ports except for the bowl vent, which I just left open. The truck runs great now. Better than it ever did.

The charcoal canister is on the back burner now, as I smashed a deer the second time I drove the truck after getting it running right. :evil: And, of course the insurance company is trying to chisel me because of the age of the truck. :roll:


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PostPosted: Fri Jul 20, 2018 8:20 am 
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Turbo Slant 6

Joined: Fri Apr 16, 2004 10:50 am
Posts: 647
Location: Stevensville, ON
Car Model*:
The video reports that the charcoal canister gets saturated with liquid fuel from percolation. With liquid fuel in the canister, I thought that it could be possible for charcoal could be drawn back into the carburetor with liquid gasoline when the canister was getting purged.

_________________
1965 Plymouth Barracuda,
225 engine, Quadrajet, HEI, Dutra Duals, 904 Torqueflite, 2.76:1 axle, Addco front bar
Rods & Relics - Fort Erie, ON / Collector Car Tech


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PostPosted: Fri Jul 20, 2018 2:17 pm 
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TBI Slant 6

Joined: Sat Mar 19, 2016 7:25 pm
Posts: 120
Location: SW PA
Car Model*:
beat_truck wrote:
That article had one interesting bit of information. It said "The canister must be kept upright, with the ports at the top."

Mine is mounted horizontally. :roll: It looks factory, but with the way some things on the truck have been hacked in the past, it very well may not be. It is mounted to the inner fender, and I know the fender on that side was changed at some point. I really can't remember how the ones in the trucks in the junkyard were mounted.

You are correct, older Dakota's canisters were also mounted horizontally along the pass. side frame rail,
there were actually 2 on the carb'd 3.9L ones(Mine). This was a problem on a number of Mopar's fleet
including the carb'd 2.2L FWD cars, and there is/was a TSB to do as DadTruck suggested, put a metal
inline fuel filter in the vent hose. I had to fix a silver Turismo 5spd for exactly this, the bits would get
pulled up into the main jet(s) when winding the engine up, it would surge and fall on it's face 'til You got
out of it. Sometimes they would float away and it would run OK for a bit, but they'd pay the jets a visit
again every time.


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PostPosted: Sun Jul 22, 2018 6:16 pm 
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EFI Slant 6
User avatar

Joined: Sun Feb 08, 2004 4:30 pm
Posts: 355
Location: West Mifflin PA
Car Model*: 1967 Dodge Dart 270
I had the same problem on my 86 D150. The charcoal canister basically exploded at highway speed. It caused total havoc with my Holley 1945. I had to tear it apart 3 times and clean it just to make it home 3 hrs away. Replaced all the hoses, added fuel filters to the vac hoses, change pcv valve and still was having issues. That stuff contaminated everything. I followed the directions (per the allpar page link) installed a new vacuum canister with separate purge valve. So far so good. :D

_________________
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PostPosted: Wed Jul 25, 2018 2:22 pm 
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Supercharged
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Joined: Sat Nov 27, 2004 8:03 pm
Posts: 4511
Location: IRWIN PA
Car Model*:
I have wanted to do the charcoal can upgrade on my 70 duster for a while.. never quute got to it yet.

I have the canister but have to work out the purge valve and switch as its an Efi car.



Welcome to the forum.

Where in SW Pennsylvania are you located?

Greg

_________________
Greg Ondayko
69 Dart http://www.youtube.com/hyperpack
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PostPosted: Fri Jul 27, 2018 11:26 pm 
Offline
1 BBL (New)

Joined: Sat Jul 15, 2017 9:12 pm
Posts: 6
Location: SW PA
Car Model*: 1983 Dodge D150 pickup 225 \6 auto
Greg Ondayko wrote:
I have wanted to do the charcoal can upgrade on my 70 duster for a while.. never quute got to it yet.

I have the canister but have to work out the purge valve and switch as its an Efi car.



Welcome to the forum.

Where in SW Pennsylvania are you located?

Greg

Farmington. It's south of Uniontown, a few miles from the PA/WV border.


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PostPosted: Sun Jul 29, 2018 4:33 am 
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Supercharged
User avatar

Joined: Sat Nov 27, 2004 8:03 pm
Posts: 4511
Location: IRWIN PA
Car Model*:
Ahh yes I have driven through there a few times on the way to wv or md.

Keep on slantin'

Greg

_________________
Greg Ondayko
69 Dart http://www.youtube.com/hyperpack
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