Hello all
at idle sometimes my truck will surge up and down almost to the point of stalling.
just got the ride so know little about it.
mods include. Coolant lines removed from throttle body, MSD coil, MSD 6AL cod box with 6000 rpm chip piggy backed into system, and K&N air and oil filters.
timing is set to 12 degrees with timing plug removed.
cat was removed and flow master muffler installed
the rest of exhaust looks stock.
there was build up around air idle motor but I cleaned it.
dizzy cap and rotor are clean and look good.
MSD wires also look good will ohm this weekend
Now all to check this weekend while front end is off getting a new radiator core support and headlight upgrade.
oh yes check engine light works but is not coming on to say there is a issue.
it has a Air speed density setup so
could be map sensor, air idle valve, TPS,
no vacume leaks that I see or hear will check plugs also this weekend.
sorry so long just giving the facts that I know of.

 

I'd be looking at the MAP sensor and the IAC.