So i guess its about time i see if my truck can stump you boys (hoping it CAN'T).
I call it the Haunted Engine. its a bit....well think of that crazy uncle you never tell your friends about...thats my engine in a way lol.
Anyways,
She's Surging between 1G Rpm-2,700rpm's as it wishes. and idle is normaly around 1,500rpm ( i know this is VERY high) it should be idleing around 700rpm's.
I have replaced ICU,TCU, checked for vacume leaks, replaced all fuel pumps,filters,gas lines, Fresh tune up. new engine wiring harness. and yet still it power surges like crazy. Like right now as i'am explaining this i have the truck warming up and i can hear it surging. wait....i no longer hear my truck at all..............Oh there it is. lol. Anyways What makes a 4.9lt surg like this? i cant figure it out!
keep in mind if i drive it its fine, it has full power, doesnt stall out. just such a high idle that i can let the clutch out, get out of the truck and the truck will take off acrosst the drive way like a bullet! Any Ideas?
-Way

 

What might you have is the infamous lean surge. In those rpm ranges the fuel mix is leaning out this causes the uneven running. The 300 cid L6 does not have a timing chain so that is out. Have you checked the timing to see if you have a worn out distributor if the bushes on the dirstributor are worn it will let the distributor shaft whobble which causes the dwell angle to change a little which will affect the idle. Slap a timing light on it to see if the timing jumpsaround a little.

 

Already tried. all set on timing. the distrib. is brand new i replaced it before i put the engine in. Far as fuel being to lean, im not sure i have run super, and regular and it hasnt made much else of any difference. im gona shoot the engine and put a 460 in it real soon hear lol.
Stupid Haunted engine!
-Way

 

What happens if you unplug the Idle Air Control (IAC) solenoid?

Also, could you change your font color to a darker color? Hard for these old eyes to read. :-)

 

Yep, I say change the IAC valve.

 

Nothing happends, no i know your gona say its bad, trust me its not iv put 3 on one being off a buddies truck that we know is good and other two being brand new.
As for the font color, It's my trademark Can you just darken your screen? it seems fine hear
-Way

 

my 5.0 has the same problem and i cant get er solved either shoulda kept my dodge

 

Now now what kind of talk is that! I'd rather have a surging prob then a tranny eater!
-Way