Low RPM Stumble/Hesitation Help (1 Viewer)

Joined
Dec 21, 2015
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Chicago Area
Thanks in advance for helping a new guy out. Took delivery of the '60 last Saturday and it stumbles/hesitates during acceleration in low RPM in first and second. It is better in third and seems fine in fourth. I have done some extensive reading here and have some ideas what to do. I tried the carb cleaner at the base of the carb trick and the small area I tried did not increase RPMs. How the heck do you get the carb cleaner in those areas with all that stuff around it?

I talked to Cruiser Classics who performed all the work on it in May and they said they do all their tuning for high altitude since they are at 7,000 feet. Told them I am at 740 feet and he suggested I retard the timing to factory spec at 7 degrees. I see that is a matter of lining up the arrow with the BB. Should be easy enough. Thoughts from you guys who have brought a high altitude truck down to close to sea level please? Will I need to re-jet the carb? I hope not... I do not think there is a vacuum leak as CC would not let a truck leave their shop running lousy. They also replaced the thermostat, but the gauge only reads slightly above C not equally in between C and H. Truck seems to warm up enough as if the thermostat is working. Do they have somewhat inaccurate gauges?

Couple other little questions. The plastic inner front fender skirts are missing of course, is the SOR two piece kit the go to for replacement? I see they offer the front and rear pieces separate for a higher price individually than the kit.

The driver's exterior door handle sits lower than flush. Before I fully take apart the door, is this a fixable issue or should I not waste my time?
 
Joined
Aug 16, 2018
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255
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Mass/NH Border
Door handle is just missing some rubber bump stops. Lift it open and look in where you fingers pull. You will see two holes that your missing rubber bumpers push into or you will see flattened bumpers.
Someone makes fender apron kits, but cant remember who. I'm sure they will chime in.
 
Joined
Jan 6, 2004
Messages
1,045
I would disconnect the egr vacuum line and drive it .. if stumble is not there then it’s the standard egr stumble.
 
Joined
Dec 14, 2005
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Location
colorado
Thanks in advance for helping a new guy out. Took delivery of the '60 last Saturday and it stumbles/hesitates during acceleration in low RPM in first and second. It is better in third and seems fine in fourth. I have done some extensive reading here and have some ideas what to do. I tried the carb cleaner at the base of the carb trick and the small area I tried did not increase RPMs. How the heck do you get the carb cleaner in those areas with all that stuff around it?

I talked to Cruiser Classics who performed all the work on it in May and they said they do all their tuning for high altitude since they are at 7,000 feet. Told them I am at 740 feet and he suggested I retard the timing to factory spec at 7 degrees. I see that is a matter of lining up the arrow with the BB. Should be easy enough. Thoughts from you guys who have brought a high altitude truck down to close to sea level please? Will I need to re-jet the carb? I hope not... I do not think there is a vacuum leak as CC would not let a truck leave their shop running lousy. They also replaced the thermostat, but the gauge only reads slightly above C not equally in between C and H. Truck seems to warm up enough as if the thermostat is working. Do they have somewhat inaccurate gauges?

Couple other little questions. The plastic inner front fender skirts are missing of course, is the SOR two piece kit the go to for replacement? I see they offer the front and rear pieces separate for a higher price individually than the kit.

The driver's exterior door handle sits lower than flush. Before I fully take apart the door, is this a fixable issue or should I not waste my time?
That would be a classic symptom the accelerator pump not pushing enough fuel down the Venturi when you're accelerating from a very low speed. Try pumping the accelerator pump several times when you're trying to accelerate. No I'm not talking about pushing it down once and then holding on the foot pedal but try to pump at several different times and see if the hesitation disappears. If that's the case then you have a leaking acceleration pump or it's not being pushed fast enough and that can be adjusted.
 

g-man

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Sep 5, 2006
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Charlottesville VA
Hesitation at idle but smooths out could also be a vacuum leak. Check your vacuum hoses to see if any are loose. Listen for hissing. Make sure your fuel cut solenoid is working...they usually fail because the electrical connection comes loose where it plugs at the side of the carb. You can check this by having someone turn the key to the on position and listen for a click from the carb.

Trail Tailor offers apron seals: Apron Seals (trail-tailor.com)

For the exterior door handle we need more info, Is the pull handle loose inside the door handle assembly? Is the entire assembly loose on the metal door? The latter can be fixed easiest by doing as you mention...pull the door card and see what is going on from the inside to reposition etc..

.
 
Joined
Jan 6, 2004
Messages
1,045
The one that connects to the top of it and plug it with a small screw or something in the end coming from the modulator.(the round thing with a few vacuum lines going to it) tho the egr valve
 
Joined
Dec 21, 2015
Messages
50
Location
Chicago Area
Thanks for the EGR suggestion guys. I will give that a go.

g-man, the truck starts and idles beautifully. I will check the fuel cut solenoid as you suggested, though.

MrM, thanks for the door handle intel. Yep, the rubber stops are crushed or missing. Where the heck do you source those?
 

NeverGiveUpYota

Dare me.
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East Hampton, CT
I second the classic acc pump being bad. They have a leather skirt that allows them to slide up and down in its bore hole. Aftermarket sometime come w/ a rubber skirt. Napa I think has one that leather but not sure. A full rebuild kit from O’Reilly has the leather and costs about $45. Just buy it and hang onto the extras cuz you might need them later. Soak the leather plunger in 90 wt for a few hours before install. Very easy to replace. I or others can walk you through. Oy carb horn (top section needs to come off) to do it.
 
Joined
Dec 21, 2015
Messages
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Location
Chicago Area
Disconnected the EGR vacuum line and plugged it up than went for a test drive. Seems to be the problem. Thanks for the suggestions. Need to search the forum for how to fix this. Is the EGR rebuildable or should I just buy a new one?
 
Joined
Jan 6, 2004
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Great! Glad problem found.. you can just run it that way and just plug it in for smog if you don’t want to deal with it now.
 
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Scottsdale, AZ
Great! Glad problem found.. you can just run it that way and just plug it in for smog if you don’t want to deal with it now.
Yep, I leave my disconnected all year and then reconnect it for emissions. You’ll also probably want to verify timing is at 7BTDC and make sure it doesn’t ping.
 
Joined
Dec 21, 2015
Messages
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Location
Chicago Area
Also, I checked the fuel cut solenoid and heard it click. I also don't hear any prominent hissing, although that is really only checking for large vacuum leaks. I need to get the emissions manual from SOR and really go through the system. Maybe a carb rebuild should be on the list? Seems like inexpensive insurance.
 

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