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Discussion Starter · #1 ·
The Fast idle is hanging up on my 260 v8. Even after the engine is warm. You can be driving down the road & not even have to put your foot on the accelator. I have a shop manual but it is not clear to me which part i have to take apart. Or whether I need to blow that part out or lubricate? The car sits around alot. If i manually press down on the fast idle linkage , it will idle normal..but out on the road as you decelerate the car still idles as if the engine were cold. If you blip the throttle a little , it will most times drop back to idle.
Any help is appreciated.
thanks
ff
 

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You need more exploration. Sometimes it is not the choke itself but the hot exhaust crossover under the carb between the heads. If this passage is plugged the car will eventually idle down but will probably idle up again if you go down the road. I have seen many 289/302 amd other makes that are plugged so bad you need to take a chisel and hammer to open it up. Good luck.
 

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Discussion Starter · #3 ·
what would cause it to be blocked? This engine was completely tore down & balanced less than 1000 miles ago(about 12 years ago)...it probably only gets driven 50 -100 miles a year.

thanks
ff
 

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Sounds like you just need to adjust the choke a little...
There is a black housing on the carb (most likely) with three small screws around it.. (its about 2" round and about 1/2" thick.) loosen it up just a little bit and (it should have some marks in it and an arrow saying rich/lean ) turn it to lean just one notich. and try that.. it might just be on the edge of being right so don't move it much.. also some WD40 might help..
tim


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<font size=-1>[ This Message was edited by: pedal2themetal45 on 8/14/06 10:36pm ]</font>
 

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Do you have the black bakelite / ceramic choke cap? If so it sounds like that is out of adjustment, maybe too much spring tension on it. I've found the best way to adjust it is on a cold engine. The sequence I use is this:
Engine off...remove the air cleaner and open the throttle by hand all the way and release. This sets the choke.
Loosen the three screws that hold the black cap and rotate it until the choke opens....then gradually rotate it in the opposite direction until it closes.
There is a notch on the housing at 12:00 dead center with a bunch of notches to the left and right of it. This a reference for rich and lean. The center on is called 'index'.
Index will usually get you in the ballpark but I've found that these are only a guide as the spring sometimes weakens over time in the cap and certain replacement caps are wound different.
Once you have the cap rotated to where the choke 'barely' closes, regardless of where the notches are, add a little more turn to set a little preload. Now your choke is set.
There is a small fast idle screw on the throttle linkage itself on the passenger side (not the small one screwing into the white plastic piece). You can adjust it to achieve the required fast idle once you fire the engine up. The engine should fire up clean and have enough fast idle to 'clean up' the initial start where the choke is closed.
NOW...that got it closed and started. It now has to heat up and open. If you have the original manifolds there are two pipes that come from the pass. exhaust manifold. Once comes up and with a rubber hose end attaches to the lower portion of the air horn on the carb, the other attaches to the choke housing.
Bssically the choke housing port has a small amount of vacuum on it. It sucks fresh air from the carb fitting in the airhorn, down the pipe through the hot manifold and up and into the choke housing to provide heat to unwind that thermostatic choke coil.
NOW..if you have headers and do not have the pipes in the manifold I would recommend intalling an electric choke cap and running a 12V source to it when the key is on. The rest of the adjustment is the same. Whew! Sorry to be long winded and I didn't even ask you what sort of carb you have. This adjustment basically works on the motorcraft, holley, edelbrock etc. You need spring tension to close it when the throttle is open and you certainly need heat to open it and to 'keep it open'
 

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If you didn't adjust anything it shouldn't be out of adjustment. Just hose the throttle/choke linkage with some Gumout, probably just a little varnish buildup from gas evaporating.
 

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Discussion Starter · #8 ·
Yeah..now that's what I'm talkin' about.....after the engine is warm..I can lightly push down where arrow number 1 is pointing & the engine idles correctling...but if you give it just a little gas it hangs up & will not idle down. Choke is open & appears fine. Could some be sticking near arrow 2 in that shaft or is that the fast idle cam where arrow number 3 is pointing....that's where i think something is sticking or hanging up. I was hoping someone with more experience than me could suggest a potential problem...seems to me that's where I should look???...any thoughts?
thanks,
ff

http://users.adelphia.net/~fastfoord/PB140011.jpg

sorry..can't figure out how to post the photo..any help?

<font size=-1>[ This Message was edited by: fastfoord on 8/16/06 10:31am ]</font>
 

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If you press down on the plastic cam #1 and the idle comes down and then open the throttle and it picks back up that's not a linkage contamination problem it's a bit too much tension on the black cap as my post above describes. A dirty cam or linkage shouldn't pick up the idle again once the engine is running. I can see it on a cold start where the cap heats up and the thermostatic coil winds but the cam won't drop. Then I agree on the dirty cam. If you've been driving around town for a while and the idle goes back onto fast idle...then check the tension on the cap.
 

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Discussion Starter · #12 ·
Thanks..rcodenewf...I think you've got me going in the right direction...i fooled around with it tonight....appears to be the black choke cap needs a little adjusting....I am surprised what moving it around an 1/8" make a difference...will have to test drive.

thanks for the help.

ff
 

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Even if the cap is misadjusted the choke will eventually open all the way and not reclose especially during the warm weather. It may run like crap until this point but it will still open if all of your vacuum and heat passages are open and functioning. several people have given you helpful hints on this, keep trying.
 

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Discussion Starter · #14 ·
Test drove it tonight...the fast idle went off & stayed off after a reasonable period of time. Apparently taking a little bit of spring out did the trick. It still "stumbles" or hesitates a little when the engine is still not up to operating temperature. Should I turn the fast idle setting on the backside? Would that help? If so...do i turn it in or out? I would imagine 1/4 or turn or so ought to do it?

thanks
ff

p.s. Here's what you're dealing with:

http://users.adelphia.net/~fastfoord/IMG_0141.JPG
 

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What you have probably done is got around a result and not the cause of your problem. If the engine stumbles when cold it is probably too lean whan cold and could use a little more choke. Goes back too the choke heat problem. Should be acceptable during the summer will probably bother more as it gets colder. By the way great car beautiful
 

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One more thing to check also.
In the picture #3 has a little piston looking part inside.
Check for corrosion and crap in it.
It can hang up and cause your problem also.
 
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