I have a 98 5.9L, 4x4. Starts right up and idles good when cold. Then when warmed up,the engine light comes on and stalls at low idle, coming to a stop, trying to shift to R, etc. My code scanner has 3 cods: Mult misfire, and misfire in cylinders 5 and 6. Ive been reading to see what I can do: IAC, TB cleaning. Anything else?

 

cap, wires, rotor button, spark plug routing maybe

 

new update. my brake light and abs llight came on. i am barely able to get it running down the road . when i get it doing it will spit and sputter around when i start to slow down. if i put it in 2 it will pick up until i get to a certain speed then spit and sputter until i throw it into 1 and the same thing run strong until i drop to a certain speed. what is going on. it is getting worse the more i mess with it. about time to grab my ankles and let someone else mess with it

 

WTF Is up with these trucks???? I'm haveing the same probles with my truck too. start fine when it's cold and then starts and dies after it's warmed up. It also died on me last night while driveing through town at 30MPH. One thing I noticed about mine is when you let off the gas at highway speeds the rpms drop 500 to 1000 rpm then come back up slow.

 

At first I figured IAC given experience but,

Please tell me if this is nonapplicable,

Could it be the fuel pump?

 

I'd say plug wires. When mine got real hot two summers ago it was a plug wire shorting out.

 

Fuel pump guys... Check the fuel pressure when it starts sputtering/dieing. The pump might be over heating by the time the engine gets to full operating temp...

 

I did that on mine and I'm getting 43-45 PSI. I checked a few minutes after it died. Just long enough to run into the garage to get and hook the pressure gage. I'll see if I can hook it up and drive it till it dies and see what it is then.

 

Oh did I mention that after warm up and it starts and dies you can get it to idle if you start it and rev the engine a couple of times as soon as it starts then it will idle fine. kind of like the engine loads up and you need to blow what ever makes it die out. Also sometime when it idling the engine will sounds like I have a wild cam and it idle like a race car engine. Kinda of sound cool but I know it's not right.

 

I c your tech certified, i hope you can tell me what to do here.Sunday IChanged my fuel pump for no reason!![:@]Saturday I thought I had bought some bad gas, cuz the truck kept dying in a city 65 miles from home.I bought some Lucas injector cleaner and tried that but after fightin it for four hours it finally would not start again so my buddy brought his chevy and trailer and hauled it home. Bout a month ago I replaced original fuel pump with a used one cuz it did bout the same thing. So I figured that must've died so spent $250, and all of sunday afternoon in my brothers shop (he loves his Fords) replacing the pump. Got done, started right up, backed it out, let run bout 20 min, hopped in and it DIED. Now what do I try.It will start if i hold my foot down on the gas pedal and crank it, so it can't be a fuse, or spark, checked both and relay. Got tons of power when runnin but will die even at 2500 rpm (I have a temper). I very puzzled. Any ideas would be much appreciated. And what is a CKP?