Close

my car starts idles ruff for about 30 seconds to a minute then smoothes out on 1995 Chevrolet Impala SS

added a fuel additive, changed o2 sensors, cleaned mass air flow sensors, runs really smooth except at start

Asked by for the 1995 Chevrolet Impala SS
poss vac leak.do you have any eng codes if so post so we can adv
3 more answers
You can try changing the fuel filter. A very dirty filter can disrupt flow and volume at start-up when they are starting to plug-up. You can also try cleaning the IAC (idle air control) to see if that helps.
I would like to check fuel pressure and maybe volume. Get the datastream as well.
Cold start morning roughness that clears up... possible leaking injector (over night or if you let it sit for a while), possible head gasket issue (coolant leaking into cylinder), possible oil leaking past valve seals (hence oil fouled plug until it clears up.

Check coolant level, has it dropped at all? Leaking fuel injector has to be tested with fuel pressure tested and some other stuff. The leaking valve seals... look at the exhaust, is there any coloration during the rough running? Black, white, blue? - Keep me in the look.

Eric Sevim - Co-Owner - ASE Master Certified Technician
http://www.aplusjapaneseautorepair.com/
San Carlos, CA 650-595-2277
Qualified Local Chevrolet Shops
Qualified Chevrolet Shops For This Repair
921 N Parker St
Orange
95
Technical Ability
93
Tools & Equipment
92
Customer Service
96
Customer Amenities
Group
CLOSED NOW
(714) 486-0367
6351 Dublin Blvd
Dublin
99
Technical Ability
100
Tools & Equipment
99
Customer Service
98
Customer Amenities
Group
CLOSED NOW
(925) 203-9158