Rough Question???
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From: Alabama
Rough Question???
'78 F100, 2WD, 351W, C6 Transmission, Edelbrock 1405 carb...
I took it to have the oil changed the other day (typically I do it myself, just haven't had time, so I took it to have it changed)...while changing it the techs noticed some of the vacuum port plugs were getting brittle, so I picked up some new ones, and replaced them all. Noticed it still doesn't seem to be running smoothly. I added a video so you could all hear it, and give me some thoughts...I have checked all vacuum lines and insured they are tight and properly secured. It seems to have a "stutter" or like it is "sluggish"...thoughts?
Also, I am aware the passenger side tailpipe is lower, the hanger has been cut for ease of access to the tank (dropping the tank). Have to get it re-attached...
(Sorry for the non-professional video...budget wouldn't allow for it)
The First Video is me starting the truck up...it is about 30 seconds long...starts, revving it up a little, shutting it off...
Second Video is just of the truck running...
Any thoughts or advise???
I took it to have the oil changed the other day (typically I do it myself, just haven't had time, so I took it to have it changed)...while changing it the techs noticed some of the vacuum port plugs were getting brittle, so I picked up some new ones, and replaced them all. Noticed it still doesn't seem to be running smoothly. I added a video so you could all hear it, and give me some thoughts...I have checked all vacuum lines and insured they are tight and properly secured. It seems to have a "stutter" or like it is "sluggish"...thoughts?
Also, I am aware the passenger side tailpipe is lower, the hanger has been cut for ease of access to the tank (dropping the tank). Have to get it re-attached...
(Sorry for the non-professional video...budget wouldn't allow for it)
The First Video is me starting the truck up...it is about 30 seconds long...starts, revving it up a little, shutting it off...
Second Video is just of the truck running...
Any thoughts or advise???
Rusty Roller
Joined: Oct 2011
Posts: 1,423
Likes: 5
From: Santa Cruz Mountains
If it was running correctly before you replaced the vac hoses then that is likely where the problem lies. Maybe one hose out of place or a cap missing. I think it is a air/vac leak. Back track and check every connection paying close attention to muli-port hose connection positions; might have two switched.
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From: Alabama
If it was running correctly before you replaced the vac hoses then that is likely where the problem lies. Maybe one hose out of place or a cap missing. I think it is a air/vac leak. Back track and check every connection paying close attention to muli-port hose connection positions; might have two switched.
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Moderator
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From: Denver Metro Area, CO
Another possibility is the old plugs & hoses allowed a certain amount of a vacuum leak to be in place, and the carb was adjusted with that in effect.
Without that vacuum leak anymore, things could use some readjusting.
This is assuming everything is hooked up correctly and working properly.
Without that vacuum leak anymore, things could use some readjusting.
This is assuming everything is hooked up correctly and working properly.
Thread Starter
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From: Alabama
Another possibility is the old plugs & hoses allowed a certain amount of a vacuum leak to be in place, and the carb was adjusted with that in effect.
Without that vacuum leak anymore, things could use some readjusting.
This is assuming everything is hooked up correctly and working properly.
Without that vacuum leak anymore, things could use some readjusting.
This is assuming everything is hooked up correctly and working properly.
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Elder User
Joined: Aug 2011
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From: Sweet home Alabama
Spray carb cleaner around the bottom of the carb,lines and intake manifold listen for a change of sound....Easy way to find a vac leak!
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From: Alabama
Sprayed all over/under/around the carb...sprayed around each vacuum line, no "rise" in RPMs...
As an update, took the ole truck out to grab some dinner for myself...at idle it runs as smooth as can be, as I get into it (even just a little acceleration) it shakes and feels really rough...as soon as I let off, it smooths right out...very confused. been trying to figure it out throughout the day...checked all the vacuum lines, rechecked them, sprayed around them, scratched my head, scratched my head some more...even picked up some Seafoam to run through it...drove it around for 20+ miles, still rough running...planning to change the plugs and wires either later tonight or tomorrow...
Going with Bosh Platinum 4+, and Xact High Performance Wire Set...
Any other thoughts...
Rusty Roller
Joined: Oct 2011
Posts: 1,423
Likes: 5
From: Santa Cruz Mountains
Check the advance canister to see if it holds vacuum. If it does then run a temp hose from it to a ported vac at the carb. This will bypass all the other stuff and see if it helps the issue. Just a thought....
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From: Alabama
Any other thoughts?
Elder User
Joined: Aug 2011
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From: Sweet home Alabama
That's pretty good timing...I was just coming in to update and get a little more input...
Sprayed all over/under/around the carb...sprayed around each vacuum line, no "rise" in RPMs...
As an update, took the ole truck out to grab some dinner for myself...at idle it runs as smooth as can be, as I get into it (even just a little acceleration) it shakes and feels really rough...as soon as I let off, it smooths right out...very confused. been trying to figure it out throughout the day...checked all the vacuum lines, rechecked them, sprayed around them, scratched my head, scratched my head some more...even picked up some Seafoam to run through it...drove it around for 20+ miles, still rough running...planning to change the plugs and wires either later tonight or tomorrow...
Going with Bosh Platinum 4+, and Xact High Performance Wire Set...
Any other thoughts...
Sprayed all over/under/around the carb...sprayed around each vacuum line, no "rise" in RPMs...
As an update, took the ole truck out to grab some dinner for myself...at idle it runs as smooth as can be, as I get into it (even just a little acceleration) it shakes and feels really rough...as soon as I let off, it smooths right out...very confused. been trying to figure it out throughout the day...checked all the vacuum lines, rechecked them, sprayed around them, scratched my head, scratched my head some more...even picked up some Seafoam to run through it...drove it around for 20+ miles, still rough running...planning to change the plugs and wires either later tonight or tomorrow...
Going with Bosh Platinum 4+, and Xact High Performance Wire Set...
Any other thoughts...
Moderator
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Posts: 22,415
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From: Denver Metro Area, CO
In ither case, I agree with OldStyle in that the problem most likely is a result of your changing the hoses & caps so I'd be focusing there and not replacing yet more parts that were never touched.
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From: Alabama
In your first post, you say they're brittle but here you're saying they "were new." Which is it?
In ither case, I agree with OldStyle in that the problem most likely is a result of your changing the hoses & caps so I'd be focusing there and not replacing yet more parts that were never touched.
In ither case, I agree with OldStyle in that the problem most likely is a result of your changing the hoses & caps so I'd be focusing there and not replacing yet more parts that were never touched.
As for the plugs and wires, they have been on my list to replace for a little while now, so yeah I spent the money now, as opposed to say within the next few weeks...
The only other part that was touched was the PCV valve that attaches from the passenger side valve cover to the carb. I did spray around it as well earlier today, as well as all around the base of the carb...
As for the fuel issue, it could be a possibility...I add Ethanol (E85) reducer to each tank, and try to run a can of Seafoam once every other month...Last fill up was about a week - 10 days ago...
Elder User
Joined: Aug 2011
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From: Sweet home Alabama
If you have a carb you cant run E85 you want to switch to a fuel injection system...Any thing more then 10% and it will run like crap and it wrecks anything thats rubber and metal fuel lines too....
You can run it if you get a methanol carb but big $$$$ and instead of 8-10 mpg you'll get 5-8 mpg's that stuff is crap!