Rough Idle Problem Help!

1989 Chev Suburban 4x4 350 tbi. I have an idle problem which has gotten steadily worse over the last few weeks/months and now, of course, the day before I leave for a trip to the woods it is idling worse than ever.

In order not to pollute anyones thinking I will simply tell you what I have done recently:

replace cracked rh exh manifold w/Aftermarket replacement
replace plugs/cap/rotor/wires
replace fuel filter
replace o2 sensor

The idle initially seemed to be intermittent but now, if the engine is at operating temp, there will be a stumbly idle which gets increasingly rough.

Any suggestions where to start with this would be MUCH appreciated as I have about a day to fix it or sit home...

THANKS!

KH

On the 89 TBI there is a Idle control valve that most likley need to be cleaned. Remove it and clean the black gunk off of it and in the TBI unit also. Spray the entire unit with cleaner. Also check and make sure that the EGR valve is not trying to open at Idle . Pull the vac line off of it and plug it and see if the Idle smooths out any.

DEAD #6 compression = 30 rest of them are 125....busted ring or burnt ex valve...thanks though

that sucks
we do not see to many like that!!!
put some oil in that cylinder and re do the comperssion test and see if the numbers change.