Rough idle, cruise control also stopped working

Does it run rough at hot idle ? How many miles ? Any recent work done on engine ?

Check the idle air control on the throttle body it is on when the engine is first started stays on until the engine is warmed up.

The PO 316 is still misfires om first 1000 revolutions
so the shop did a poor job for you on resolveing the
cylinder misfires

Try a diffferent shop

Have to clean the MAF Sensor & replace upstream
oxygen sensors if over 100,000 miles

Need the correct oem spark spark plugs/any brand

No reason the gas filter should be clogged unless it was in
the car for 10 years

Fuel pressure should be checked

Need to check for cylinder misfires on a road test of 20
miles or more with professional software in Mode#06

long post.
ill reduce it for you.
misfires. (is RPM below 700 then misfire can be normal) for idle speed controls dead.
ISC the isc controls speed, of idle,.
mine stuck like zillion times, in 400k miles. endless.sticking
mine was a tiny gutless stepper motor drive ISC valve.
the cone valve is side gets nasty and sticks (
(PCV gases caused as seen on all engines)
i clean it.
the proof is the easy press of right foot easy raises idle back to 700rpm and engine stops misfiring.
ever get a tuneup this decade or running spark parts 500,0000 miles
for the new world record.?


now the tricky part of ISC, , fully explained in the SM serv. man.
the PCM learns its behaviors.
it learns all hot start settings and cold
so when you key on, it goes to the correct HISTORICAL spot.
if it can move there(sticks) engine car race.
or run too slow,
cold start would be worse, as hot isc is more closed
so if sticks there closed, the next cold start will be horrid
some newer manuals telly you to add 5% throttle if car is hard starting this is so common.

clean it. end story.
ISC

yea id definately try cleaning ur throttle body 1st. My 03 1500hd had the exact same bad idle after my battery went bad it would die at lights unless i kept foot on gas i cleaned throttle body runs perfect now took 30min cost 8$ for cleaner at autozone and theres how to videos on you tube

assuming there are no other performance issues after warm up...Pull any OBD II codes and go from there., Possible IAC - Idle Air Control circuit problem, injectors stuck or leaking, dirty throttle body, Poor Gas. Change to a different fuel station- possibly getting water in fuel tank after fill up. Good Luck!

have your idle control switch check, easy and inexpensive to replace. The idle control switch is what keep the engine stay idle. also have your throttle body clean by a professional having that many miles, it will give you better gas mileage.

Sounds like you have a vacuam leak.
Check the vacuom hose to the cruise canister........and work yuor way back to the source. I'll bet you find a hose off. Also, listen for any "hissing" sounds (obviously, not the carb).
Bet that solves ALL your probs.

Just trowing some suggestions out there, but, I would check the idle air control valve (solenoid) or the throttle position sensor. If they check out then my last guess would be the map sensor or the vaccuum to the map sensor. Hope I was able to help. Best wishes.

I had the same problem along with a rough idle and found out it was my EVAP canister.