Just ut a fresh 5.0 in my 92 Nite F150.anyone heard of one suging after the motor runs a few minutes?Starts up o.k. but after it starts to warm up the thing starts surging till it reaches a point that it just dies.It wil stay running if I bump the idle up w/ the excellerator to around 1200 rpm.hen I let off it doesnt take long before it stalls.Only mods are throttle body spacer,and heaers,eaky ones at that(right now) and I changed over to a 351 firing order.Dont know what it would affect but we cleaned the throttle body w/ t.b. cleaner then noticed the lable,not to clean it.Any helpor insight would be welcome...Thanks

 

My guess would be the idle air control valve , try removing it from the throttle body and giving it a good cleaning. Also check the voltage it should not exceed 1 volts . For good good throttle response .999 volts is ideal.

 

If you are refering to the idle speed motor I'll try that tommorrow.I'm kinda leaning toward that or throttle positioning sensor which I will also run voltage test on.I was told by a mechanic to unhook the battery for 5 mins. and then reconnect try.This I had enough time to do tonite..didnt help.He also told me that the idle base speed could need adjusted.Dont know what he's talking about,let alone do it...Any clues?

 

First make sure all your vacum lines are in good shape. There are a bunch that run behind the motor. If there in good shape disconnect the one from the EGR Valve and make sure its got good sucktion (do this with the engine running). If its got good sucktion check out your EGR Valve. If its faulty it will make your engine do all kinds of wierd things.