Ford Mustang Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
hi, i'm working on a 67', with a 289, 2 barrel carb. automatic transmission. when idling car runs fine. when i put into gear in rumbles like crazy. i've checked compression, spark plugs, ignition wires. they all check ok. when i pull wires off the distributor cap for cylinders 2, 5 ,6 ,and 7 there is no change in idle. also, when i spray carb cleaner in to one side of carb, idle speeds up. when i spray into other side it boggs, huh!
can anyone help me out. i'm stuck. timing is ok. i don't know what else to check. i don't want to guess that it could be manifold if it isn't. please help!
 

·
Registered
Joined
·
11 Posts
my guess would be that the idle jet on the side of the carb that runs better with carb cleaner is plugged. Try completley removing the idle mixture screw fron that side of the carb & spraying some carb cleaner in through the hole where the screw goes. (motor off)
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
thanks for your guess john. but, how would that explain why when i pull the ignition wires off the cap for cylinders 2, 5 ,6 and 7 there is no change in the way it runs. it's as if it is running on only 4 cylinders.
 

·
Registered
Joined
·
50 Posts
I was working on my 66' two nights ago, and the same thing happened to me. We adjusted everything on the carb and still nothing. It ended up being the firing order on the distributor cap. It was all off.
 

·
Registered
Joined
·
400 Posts
+1 on the wiring order. Also check your distributor to make sure you're getting spark at the plug for the cylinders you mentioned.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
+1 on the wiring order. Also check your distributor to make sure you're getting spark at the plug for the cylinders you mentioned.
firing order is right, also, getting spark to all cylinders as well.
i'm thinking it's gotta be the intake manifold or gasket. some kind of vacuum leak. cause it runs rough in gear when stopped, but once up to speed it kind of smoothes out. i just want to be sure before i tear it apart. thanks for the replies.
 

·
Registered
Joined
·
11 Posts
well if you look at the intake runners I believe those are primarily fed by the same side if the carb. If the intake gasket would be all 4 on the same side (1234 or 5678)
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
yeah, this is puzzling. tomorrow i'm gonna put it on top dead center and see if it is lined up on 1. this engine only has 70,000 original mi. and was babied and then sat for awhile. maybe, if i'm not mistaken that timing chain has a plastic gear. maybe it wore and jumped a tooth.
any other suggestions appreciated. i'll post what i find.
thanks.
 

·
Registered
Joined
·
324 Posts
my guess would be that the idle jet on the side of the carb that runs better with carb cleaner is plugged. Try completley removing the idle mixture screw fron that side of the carb & spraying some carb cleaner in through the hole where the screw goes. (motor off)
I second this solution. It sounds like the idle jet passage is plugged. I havent dealt with the fords doing this. But the old chevys with a quadrajet carb the idle pickup tube in the carb would fall out and they would miss at idle on either 3,5,2,8 or 1,4,6,7 depending on which side fell out. I haven't paid attention to how the cyls are fed on the 289 but it sounds like the same condition check the carb I would suggest take top of carb and clean all passages with compressed air or carb spray cleaner. Make sure you dont have debris floating around in carb bowl.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #10
just wanted to post that i took the carb off, got a carb kit, nothing really need to be replaced. but i did take the air/fuel screws out. (their is no "idle jet screw"), but anyway, blew air through all the holes. put carb back on, and it still ran rough. was driving it to a friend of mine, who runs a carberator shop. when i got off the freeway, it was like it magically fixed itself. i had to re adjust the idle(it was idling high) now it runs fine. so i don't know if something was stuck or there was some debris somewhere or what? but now fires on all cylinders and runs like a top! but, i wanted to thank all those who tried to help me out. it is appreciated!!
 
1 - 10 of 10 Posts
Top