'85 4R newly rebuilt top end. When engine is warmed up the idle will dip down every 4-5 seconds when I brake. I'm sure it is a vacuum issue but I don't know how to solve it. All my vacuum lines are new. Where do I start?
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Common "adjustment needed" (You think you're soooo great...... boy if I met you in a dark alley......)
"brake booster iirc"
What is IIRC??
if i recall correctly?
A dip at idle can also be a problem with the brake booster iirc while pressing on the brakes.
So what are you now, nerd?Sorry, Im becoming a nerd in my later internet days.
When you turn the screw in all the way, does the engine stall? Yes? Good. No? The idle air valve is clogged up and isn't working. Probably corroded.I just got one of these trucks about a week ago and I'm having the same issue. After it's warm the idle dips upon braking. I've all ready tried adjusting the idle screw and it's turned all the way in with no more ability to turn further.
any other suggestions?
When you turn the screw in all the way, does the engine stall? Yes? Good. No? The idle air valve is clogged up and isn't working. Probably corroded.
Or possible vacuum leak somewhereThe idle air valve is clogged up and isn't working. Probably corroded.