The truck refuses to run normally unless the choke is completely closed...
which suggests that it is getting air from another source, which is unexplainable...
the truck stutters as you push on the accelerator..
has anyone had this experience, I am out of ideas...and cannot figure out why the truck is doing this, thank you
-Thomas
Help! Unexplained Problem
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dr deuce
- Brigadier General
- Posts: 2400
- Joined: Thu Jun 08, 2006 1:10 am
- Location: Pembroke NH
- Contact:
There are two possibilities here:
1. Vacume leak
2. Fuel starvation
1. For the vacume leak, disconnect the metal line from the booster at the check valve on the manifold. Put a bolt into the check valve and tape it up with electrical tape. Try that (don't drive the truck as you now have no booster). The booster line is the only place that could admit enough air to demand a full choke situation. A individual manifold port leak will make it run rough and if the wiper line was open, only a little cholke would be necessary.
2. For the fuel issue, disconnect the fuel line to the carb and have someone crank the starter while you hold a container under the line to catch the fuel from the now open gas line. If that is appriopiate, then it would suggest something clogged in the carb.
1. Vacume leak
2. Fuel starvation
1. For the vacume leak, disconnect the metal line from the booster at the check valve on the manifold. Put a bolt into the check valve and tape it up with electrical tape. Try that (don't drive the truck as you now have no booster). The booster line is the only place that could admit enough air to demand a full choke situation. A individual manifold port leak will make it run rough and if the wiper line was open, only a little cholke would be necessary.
2. For the fuel issue, disconnect the fuel line to the carb and have someone crank the starter while you hold a container under the line to catch the fuel from the now open gas line. If that is appriopiate, then it would suggest something clogged in the carb.
Dr Deuce Over 50,000 driven miles in a CCKW
1942 CCKW closed cab shopvan
1943 CCKW closed cab cargo w/M32 MG mount
1944 CCKW open cab LeRoi Kompressor
1944 CCKW open cab F1 Aircraft fueler tanker
1945 CCKW open cab cargo w/artic cab
1942 Chev cargo
1942 Chev K51 Panel
1944 Chev M6 Bomb Truck
1942 GPW Jeep
http://home.comcast.net/~cckw/wsb/html/ ... 59870.html
1942 CCKW closed cab shopvan
1943 CCKW closed cab cargo w/M32 MG mount
1944 CCKW open cab LeRoi Kompressor
1944 CCKW open cab F1 Aircraft fueler tanker
1945 CCKW open cab cargo w/artic cab
1942 Chev cargo
1942 Chev K51 Panel
1944 Chev M6 Bomb Truck
1942 GPW Jeep
http://home.comcast.net/~cckw/wsb/html/ ... 59870.html
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Thomas
- Draftee
- Posts: 3
- Joined: Thu Jun 08, 2006 1:10 am
Thank You
Thank You for your quick response 
I have eliminated all external vacuum sources and the fuel pump is putting out 5 PSI to the Carb and I still need full choke to obtain a steady 20 inches of vacuum at the wiper line. With the Choke Open I can get 19 erratic inches of vacuum. Do you have any other ideas? b/c this is very baffling to me...
Thank you,
-Thomas
I have eliminated all external vacuum sources and the fuel pump is putting out 5 PSI to the Carb and I still need full choke to obtain a steady 20 inches of vacuum at the wiper line. With the Choke Open I can get 19 erratic inches of vacuum. Do you have any other ideas? b/c this is very baffling to me...
Thank you,
-Thomas
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armydriver
- Brigadier General
- Posts: 2595
- Joined: Thu Jun 08, 2006 1:10 am
- Location: San Antonio, Texas
I had pretty much the same problem and ended up having to get the carb. re-built as very small rust particles had stopped up the carb. After cleaning out the entire fuel system, filter and putting an extra in-line fuel filter just for insurance and replacing the carb, with new gaskets, she starts fine and runs great.
Good luck.
Good luck.
52 M38 Willy's
Former owner and restorer of CCKW353 " Betty Boop"
proud father of a career Army officer/Blackhawk pilot/ War in Iraq veteran
Retired high school history teacher at Lt. Colonel Robert G. Cole CMH High School, Fort Sam Houston Texas
proud great grandson of four Confederate soldiers.
great great grandson of a War of 1812 veteran
great great great grandson of 2 American Revolutionary war veterans
Former owner and restorer of CCKW353 " Betty Boop"
proud father of a career Army officer/Blackhawk pilot/ War in Iraq veteran
Retired high school history teacher at Lt. Colonel Robert G. Cole CMH High School, Fort Sam Houston Texas
proud great grandson of four Confederate soldiers.
great great grandson of a War of 1812 veteran
great great great grandson of 2 American Revolutionary war veterans
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Thomas
- Draftee
- Posts: 3
- Joined: Thu Jun 08, 2006 1:10 am
The Problem Persists
Thank You again for a quick response
I have done all of the necessary fuel system cleaning and carb cleaning.
The problem began after:
The Engine was running fine with NO hesitation on acceleration.
The next morning I tried to start the engine and I discovered one intake valve was stuck open (due to varnished gasoline)
So I removed the head and cleaned all the varnish out, did a valve job, replaced the head gasket, made stainless steel rings to fit into the counterbores of the head and intake manifold, and used new manifold gaskets.
I then warmed up the engine and retorqued the head bolts and adjusted the valve lash again.
***THE ENGINE RUNS with CHOKE FULLY CLOSED ***
So, I used oil and WD-40 around all vacuum areas and they all show no leakage.
The hydrovac line, wiper line, and PCV Tube port were all capped off, and still THE ENGINE RUNS with CHOKE FULLY CLOSED I AM SO BAFFLED!
I decided to drive the truck (about 15 miles) even though it has this strange problem and the truck ran well. I got it up to 40 MPH in 5th gear with the choke still fully closed... opening the choke even just slightly while running causes hesitation in the engine.
I am out of ideas and I really appreciate everyone's help, Thank You
-Thomas
I have done all of the necessary fuel system cleaning and carb cleaning.
The problem began after:
The Engine was running fine with NO hesitation on acceleration.
The next morning I tried to start the engine and I discovered one intake valve was stuck open (due to varnished gasoline)
So I removed the head and cleaned all the varnish out, did a valve job, replaced the head gasket, made stainless steel rings to fit into the counterbores of the head and intake manifold, and used new manifold gaskets.
I then warmed up the engine and retorqued the head bolts and adjusted the valve lash again.
***THE ENGINE RUNS with CHOKE FULLY CLOSED ***
So, I used oil and WD-40 around all vacuum areas and they all show no leakage.
The hydrovac line, wiper line, and PCV Tube port were all capped off, and still THE ENGINE RUNS with CHOKE FULLY CLOSED I AM SO BAFFLED!
I decided to drive the truck (about 15 miles) even though it has this strange problem and the truck ran well. I got it up to 40 MPH in 5th gear with the choke still fully closed... opening the choke even just slightly while running causes hesitation in the engine.
I am out of ideas and I really appreciate everyone's help, Thank You
-Thomas
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Karoshi
- Lieutenant Colonel
- Posts: 563
- Joined: Thu Jun 08, 2006 1:10 am
- Location: UK
Sounds to me like a carb fault. If I understand you correctly the mixture is weak, too weak to maintain the engine under load. So you have to apply choke to richen the mixture to make it run?
If this is correct I would suspect a blocked dip tube in the carb, or blocked main jet. Have you checked the fuel filter for dirt? Have you pulled the carb, and inspected the float bowl for dirt?
Touchy things these Deuce carbs, especially if you have dirty fuel from a rusty tank.
Karoshi
If this is correct I would suspect a blocked dip tube in the carb, or blocked main jet. Have you checked the fuel filter for dirt? Have you pulled the carb, and inspected the float bowl for dirt?
Touchy things these Deuce carbs, especially if you have dirty fuel from a rusty tank.
Karoshi