04 Impala rough Idle and hard warm engine starts - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Chevrolet When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-25-2013, 01:20 PM   #1
Junior Member
Thread Starter
 
Join Date: Mar 2013
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
ngehrke is on a distinguished road
Default 04 Impala rough Idle and hard warm engine starts

I have a 2004 impala with just under 95k miles. Within the last month I've been having problems with the car starting after it has been running awhile usually have to crank in 2 or 3 times for it to start. When the engine is cold it starts right up. In the last week I've started to notice a gas smell coming thru the vents and by the engine compartment and also got a check engine light for small emisson leak. This past weekend my uncle and I checked the engine found no leaks in the fuel injectors and no leaks in the lines. We went to auto zone and the guy told us it had to be the fuel pressure regulator. So we purchased a new one and rented a pressure gauge tester. We hooked up the guage per the instructions and found the pressure to be at spec when engine was cold. we ran the engine for about 15min re tested and it held pressure till the engine cut off and it bled off immediately. we replaced the regulator and seems to work better but I have also noticed while in drive stopped at a stop light the engine is ideling rough. It goes from steady to high to low to steady and I can feel the difference in the brake pedal as far as firmness. Please help!!
ngehrke is offline   Reply With Quote
Old 03-25-2013, 03:19 PM   #2
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

sounds like it may still have a vacuum leak. whens the last time for plugs/wires/filters? which engine?
jwfirebird is offline   Reply With Quote
Old 03-25-2013, 03:28 PM   #3
Junior Member
Thread Starter
 
Join Date: Mar 2013
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
ngehrke is on a distinguished road
Default

We actually changed the plugs and wires about 6 months ago. Air filters changed with oil changes. still original fuel filter. We asked the guy at autozone if we should change that and replace the EGR valve he said no it wouldnt cause these issues. and it is the standard 3400SFI
ngehrke is offline   Reply With Quote
Old 03-25-2013, 04:32 PM   #4
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

the egr might but if you dont have any codes i wouldnt worry about it. i i think the 3.4 has the iac on the side of the tb, i would clean that good and the seat. if that doesnt help, try taking carb cleaner and spraying around vacuum lines and the intake with the engine running and listen for it to change pitch
jwfirebird is offline   Reply With Quote
Old 03-26-2013, 10:28 AM   #5
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Based on your comment about the brake pedal firmness, I agree with Justin this sounds like a vacuum leak. Spraying with carb cleaner will help to locate the leak since a leak will suck the cleaner into the intake manifold and you will hear a slight change in engine RPM'*.
2kg4u is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
95 Grand Prix 3.1L Starts then dies when cold runs when warm check engine light on gabrielpanoussi Pontiac 21 01-04-2015 06:41 PM
small miss/Rough idle when warm.... CrazyGunner 1992-1999 12 12-11-2010 11:59 AM
Hard start when warm, flashing Service Engine Soon at Idle. KoryKreisler Chevrolet 15 07-02-2010 12:39 AM
rough idle and slight decreased power after warm start CJCroel 1992-1999 3 04-10-2008 09:56 PM
Update - engine surges at idle when engine is warm billha 1992-1999 8 06-28-2005 12:55 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:13 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.