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Engine Question

816 Views 9 Replies 6 Participants Last post by  66coop
I have a 289 V8w with a Weiand Action Plus manifold and Edelbrock 1406 Carb. My issue the last few days is while out cruising around the engine wants to stall and idles rough at lower speeds after its really warmed up. Another thing I noticed is if you put your hand on the valve covers you can feel a tapping on the drivers side but not on the passenger side. The carb is the only change made lately, at first I thought it may be the idle circuit because the screws we not doing anything when adjusted in and out. I removed the screws and shot some air down them to clear it out and then it was working fine again. Any thoughts on this would be appreciated. Thanks Ed
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Hello 66coop,
Sounds like we are dealing with 3 issues here that may be related

I would like to name them:
3. - VACUUM leak

Ok - lets start with issue #1

The idle screws should of course have an affect on the rpm and idle
if not - it indicates one of two things. The car is idling too fast and
beyond the idle circuit
I am going to guess that this is not the case - so we move to part two of this issue. If the motor is idling around 700 in neutral
then you should be able to change the rpm (almost kill running) by turning the idle screws in. DO NOT tighten these screws much just a gentle seat. If the motor does not almost die - it tells you there is a problem. You could try to see if the problem is in the idle circuit
to remove the idle screws and spray some carb cleaner into the holes.

NEXT ISSUE 3 - -a vacuum leak. If the idle screws don't change the rpm - -I would check for a vac laek. It could be as simple as
a hose off or cracked. I would also spray the area around the base
of the carb with carb cleaner - while the motor is running. If the rpm changes - most likely speeds up - -you have a vacuum leak.

ISSUE 2 - - I don't like to hear of a tapping feelin under the valve covers. The rocker arms do NOT touch the valve cover under normal conditions - - so I would NOT run the motor much until you
take off the valve cover and check the rockers. It is possible the rockers are loose.
I WOULD NOT - adjust anything unless you know how to adjust the rockers correctly. DO NOT just tighten the rockers - you could do more harm. If you remove the rocker and see anything that looks off - please post here if unsure what you are looking at

Well that is my novel for now.
PLease let us know what you find or see and we can help get you going correctly

Print Dad
Hey Print Dad The idle screws are working after clean out and I did spray carb cleaner around the base of the carb and I didn't notice any changes in RPM. You cant hear the tapping, you can feel it when you place your hand on the drivers side valve cover but cant feel it on the passenger side. Could a bad or out of adjustment head cause the issues I'm having.

I just watched a video on adjusting valves on a ford 289 while the engine is running is this recommended?
Do 'em cold... spin each pushrod/tighten until stops + 1/4 turn
These are what type I have adjustable right?


I just watched a video on adjusting valves on a ford 289 while the engine is running is this recommended?
That's the way I learned it and the best as far as I am concerned. The lifters adjust themselves as the engine runs and if its not running you may adjust to a different lifter height than when the engines runs. Lifters leakdown by design which is how oil gets to the rockers arms. Any lifter that is holding a valve open when the engine stops will be at least partially collapsed during a static adjustment.

The static adjustment is just to get the engine to run for the first time.
Your photos show the rocker arm nuts way down on the studs. Is all you stuff stock?

And I disagree on the adjustment advice for an engine that has any amount of miles on it. The ends of the push-rods and the sockets polish up and do not have the same friction as new ones, so there is little to no turning resistance. I almost trashed my 289 doing it that way. Everything was run down way too far. Once I just took the slop out and then the 1/4 turn it ran fine again.
I hadn't noticed the nuts being so far down on the studs. I agree, for a stock engine those indicate something is not right.

Ford's original recommendation for hydraulic valve adjustment was to turn them down 1 1/2 turns from when the slack is gone, i.e. when they quiet down with the engine running. That was later changed to 1 turn and finally to 3/4 turn. As long as they stay quiet it doesn't make much difference since the lifters self adjust as they run. As the lifters wear they leakdown faster and a more shallow adjustment (1/4 turn) will tend to run out of self adjustment range quickler.

If you adjust with the engine running the friction of the push rod ends has nothing to do with it. You sequentially loosen each rocker arm until it clatters, then tighten back until they quit clattering plus another 3/4 turn. You can easily determine when the clatter stops to less than 1/8 turn of the nut. There is no guessing as to when they turn freely or not since you don't do that. Before the engine runs you have no other choice than to adjust 3/4 turn beyond the point 'to just remove all the push rod to rocker arm clearance'. The shop manual says to 'rotate and/or move (up and down) the push rod' to determine clearance but either way is a pretty nebulous instruction.
I haven't made my irritating presence known here for awhile now, so I might as well get back into it.

I adjust rockers cold. when the push rods and rockers are used so they are polished up, I move the push rod up and down until the pushrod is down on the lifter and rocker seat, but just barely touching.

that being said, I use the long but sure to not screw things up method of adjustment. I manually turn the engine over until a valve to any given cylinder hits its full bottom dwell. (you will be able to turn the engine over with wrench slightly and the valve should not move -this is what I mean by dwell) with that valve in its dwell point, adjust the corresponding rocker. so if the exhaust is at full bottom dwell(spring compressed) adjust the intake valve. once the pushrod slop is out, I take the rocker nut a half turn. that's 1/2.

I generally like to work down one bank and one cylinder at a time so I don't lose track of where im at. this takes some time, but it has never failed me yet. best of luck!

here are some supplemental materials from my 302 budget build series. they are pedestal rockers, but the idea is the exact same minus the torque spec stuff.
I guess I will have to really to think about how I ill adjust it dont want to mess things up.
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