Page 1 of 4 1234 LastLast
Results 1 to 20 of 73

Z28 Still Has Rough Idle Wtf????

This is a discussion on Z28 Still Has Rough Idle Wtf???? within the Camaro / SS forums, part of the Vehicle Specific category; [B][/B I have a 98 Z28 with a automatic transmission. When I first got it about 8 months ago it ...

  1. #1
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Unhappy Z28 Still Has Rough Idle Wtf????

    [B][/B

    I have a 98 Z28 with a automatic transmission. When I first got it about 8 months ago it idled smooth as hell. About a month ago I noticed the idle was getting a little rough kind of surging a bit. I installed new plugs and Msd wires and put on a new fuel filter. I also got the shop to clean my MAF and put a new K and N air filter in the car. It idled smooth again when I picked the car up but when I got home in my driveway it was rough again. When I picked my car up the temperature was about 170 degrees because they just test drove it so it wasnt cold. I also noticed if I barely give it the slightest amount of gas with my foot (about 1100-1150 RPMs) it shakes a bit and is rough(while in park). When I drive the car it runs great with no hesitation and runs strong untill I stop at a stop sign or traffic light then the rough idle. The check engine light does not come on either (and it does work). My car is completely stock also.Can anyone tell me what to do next or what to look for? It is really bugging me because I gotta have my car running right.

    Thanks for any help on this fellas----Mike

  2. #2
    Awaiting Activation
    Join Date
    Mar 2006
    Location
    LS1 land
    Age
    29
    Posts
    1,667
    What rpms do you idle at? have you checked out the throttle body at all? It could be dirty. Could be gunked up where the air comes through that is supplied for idle. Also make sure the cable is on correctly. Take the cable off then put it back on for shits and giggles.

  3. #3
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Quote Originally Posted by 99blueZ View Post
    What rpms do you idle at? have you checked out the throttle body at all? It could be dirty. Could be gunked up where the air comes through that is supplied for idle. Also make sure the cable is on correctly. Take the cable off then put it back on for shits and giggles.
    My car idles at about 900 rpms. I cant work on my car because I recently had back surgery so I have to get the shop to do it. The shop I go to only works on F-bodies and corvettes and were rated really well in corvette magazine. I will have them take a look at the throttle body though thanks. Do you think putting it on the diagnostic computer would be worth a shot??
    Thanks for your time!!

  4. #4
    Awaiting Activation
    Join Date
    Mar 2006
    Location
    LS1 land
    Age
    29
    Posts
    1,667
    Quote Originally Posted by deadbydawn421 View Post
    My car idles at about 900 rpms. I cant work on my car because I recently had back surgery so I have to get the shop to do it. The shop I go to only works on F-bodies and corvettes and were rated really well in corvette magazine. I will have them take a look at the throttle body though thanks. Do you think putting it on the diagnostic computer would be worth a shot??
    Thanks for your time!!
    well instead of spending $$ at a shop do you think a neighbor could take the throttle body off for you? Its verrry simple. Just slip off the bellows, then 3 bolts, then 2 connectors. Diagnostic might help - it could show if you have a clogged injector - which could cause poor idle.

  5. #5
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Quote Originally Posted by 99blueZ View Post
    well instead of spending $$ at a shop do you think a neighbor could take the throttle body off for you? Its verrry simple. Just slip off the bellows, then 3 bolts, then 2 connectors. Diagnostic might help - it could show if you have a clogged injector - which could cause poor idle.
    I am staying at my sisters house on a golf course and these people dont even know where the oil drain plug is!!! LOL Before I hurt my back I had a 87 IROC and I restored it and the neighbors acted like I was a redneck untill I got finished with the car. It looked showroom new and had a fortune in new parts. I miss that car. My ex got that car. A sad day for me. So off to the shop for me!! LOL

  6. #6
    Member Mjolnir's Avatar
    Join Date
    Feb 2007
    Location
    Arizona
    Posts
    456

    White/Black
    1999 Camaro z28

    One thing i think many people have learned about shops is, its ok to guess when your doing it by your self, but if you tell a shop to clean your throttle body and they know its something else they will clean it and charge you even though thats not what needed to be done. If you are going to take it to a shop point out the problem with the idle and im sure if they specalize in the feild they will be able to tell you right there without even exchange of money.

  7. #7
    Awaiting Activation
    Join Date
    Mar 2006
    Location
    LS1 land
    Age
    29
    Posts
    1,667
    Quote Originally Posted by deadbydawn421 View Post
    I am staying at my sisters house on a golf course and these people dont even know where the oil drain plug is!!! LOL Before I hurt my back I had a 87 IROC and I restored it and the neighbors acted like I was a redneck untill I got finished with the car. It looked showroom new and had a fortune in new parts. I miss that car. My ex got that car. A sad day for me. So off to the shop for me!! LOL
    damn, sucks that your ex got the IROC! Hope all goes well with the Z28 and your back! Keep us updated.

  8. #8
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Quote Originally Posted by 99blueZ View Post
    damn, sucks that your ex got the IROC! Hope all goes well with the Z28 and your back! Keep us updated.
    Yea 12 years with her and she beat me out of my car. I had the title in her name for legal reasons at the time.I loved that car too. Mainly because my father and I rebuilt everything together so it was special to me. He loved it as well. We were gonna get another IROC and do it 1 more time but I hurt my back and he had a stroke (he is beter now).I got complements every time I drove it. It was like a new car. After she screwed me over I bought the 98 z28. No woman will get this one nope. LOL. Ill let you know whats wrong as soon as I find out. Thanks

  9. #9
    ChEvY RiDiN' H.B. 00maroz28's Avatar
    Join Date
    Apr 2006
    Location
    jersey
    Age
    35
    Posts
    240

    black
    2000 camaro z28

    i have the same problem in my 2000 z28 a4... but my check engine came on too...but same exact problem rough idle...when i come to a hard stop or sitting at a light almost feels like it wants to stall (it never has) but when im driving its fine....lemme know what yours turns out to be

  10. #10
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    I sure will I am taking it in to have it looked at on Friday(march 9th) to have em look at it.

  11. #11
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    To me and this is just speculation, It sounds as if the injectors are dirty ie clogged with fuel gum/carbon etc. however if you just had the car at the shop for this then take it back to them tell them they didnt fix it and that they need to take care of it. Usually if it is a significant miss then the check engine light will flash on and off, cause poor fuel mileage etc. Being that when warm it dosent do it as badly I would suggest having the injectors cleaned, the simptoms you have extremely synonimous(s/p) with a dirty injector. just my .02

  12. #12
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Quote Originally Posted by MechanicalMehem View Post
    To me and this is just speculation, It sounds as if the injectors are dirty ie clogged with fuel gum/carbon etc. however if you just had the car at the shop for this then take it back to them tell them they didnt fix it and that they need to take care of it. Usually if it is a significant miss then the check engine light will flash on and off, cause poor fuel mileage etc. Being that when warm it dosent do it as badly I would suggest having the injectors cleaned, the simptoms you have extremely synonimous(s/p) with a dirty injector. just my .02
    I kinda thought the same so I bought somefuel injection cleaner and put it in a full tank. That tank is gone and its still rough idle. Maybe that wasnt good enough stuff. The gas milage of the car is really good as well. Hope to figure it out tomorrow. Thanks

  13. #13
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    Yeah, it seems like the stuff you put in the tank isnt potent enough to actually clean them, especially after they are already clogged, I take my truck and cars to a buddy of mines shop and have some of that bg injector stuff run through the injectors(well I actually do it myself I used to work with him at a shop). It usually takes care of it. good luck with getting it to run right!
    Last edited by MechanicalMehem; 03-09-2007 at 04:56 PM.

  14. #14
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    I took it in today and they are saying the motor mounts are old and causing it to vibrate while in park. I know the mounts are worn because when I start my car I can feel it. I am gonna replace the motor mounts and transmission mount and see what happens. I will keep yall posted. By the way I havent been under my car because of my back. How hard is it to put new motor mounts on cause they want way too much in my opinion to change them. I have put mounts in my s-10 before and it was easy. Is it really difficult on z28s because of limited space?? I have a 98 . Thanks

  15. #15
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    This is what alldata says for driver's side, you end up spending a lot of time on the gound unless you have a lift to put it on soooo its up to you, but be carefull with your back--I am copying and pasting w/o pics.

    Disconnect the Intake Air Temperature (IAT) sensor electrical connector at the duct.
    Disconnect the Mass Airflow (MAF) sensor electrical connector at the duct.
    Remove the air intake duct from the throttle body and the air cleaner box.
    Support the engine using the J4245 1,J28467-B, and the J36462-A.
    Raise and suitably support the vehicle.
    Remove the left oxidation catalytic converter.
    Remove the engine mount bracket to crossmember bolts.
    Lower the vehicle.
    Raise the left side of the engine with the support fixture.
    Raise and suitably support the vehicle.
    Remove the engine mount heat shield nuts.
    Remove the engine mount heat shield.
    Remove the engine mount bracket to block studs.
    Remove the engine mount from the vehicle.
    Separate the upper and lower mount on the bench.
    and reverse procedure to reassemble.

  16. #16
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    Right Side!
    Support the engine using the J42451,J28467-B and the J36462-A. NOTICE: When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the pan to be bent against the pump screen. This will result in a damaged oil pickup unit.
    Raise and suitably support the vehicle.
    Remove the starter motor.
    Disconnect the low oil level sensor electrical connector (1).
    Remove the negative lead bolt (1) and lead (2) from the engine block.
    Remove the engine mount bracket to crossmember bolts.
    Lower the vehicle.
    Raise the right side of the engine with the support fixture.
    Raise and suitably support the vehicle.
    Remove the engine mount bracket to block bolts.
    Remove the engine mount from the vehicle.
    Separate the upper and lower mount on the bench.


    Replace
    Front Mount
    Both Sides 3.0
    Right Side 1.8
    Left Side 2.1
    Trans mount .5

    This is the time called for in alldata, from the time it suggests to me it dosent seem that bad, but then again, I would be using a lift, air tools, have a GOOD BACK, etc. man in your condition I dont know that I would try it because you run the serious risk of putting yourself out of commission for a while! oh BTW the times it calls for are customer pay, if the shop wanted more than that times their labor rate then yes they are trying to overcharge you, go to a dealer-they are supposed to be honest! Not always the case....but are supposed to be. trans mount is no big deal.
    Man again I would say with your back, I wouldnt do it. You will have to be up and down quite a bit. Oh and with the support the engine blah blah blah, you can use a jack just put a block of wood on it so it is not metal to metal and be gentle.

  17. #17
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    Sorry for the long posts, just wanted you to have all of what alldata called for, some of the steps could probably be skipped, but if your not sure then dont skip it!
    --Justin

  18. #18
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Thanks man well I am gonna just bend over and pay them to do it. LOL
    My back is hurtin too much.

  19. #19
    Lurking MechanicalMehem's Avatar
    Join Date
    Feb 2006
    Location
    Oklahoma
    Age
    36
    Posts
    255

    white/black
    2000 z28

    Man I wasnt trying to tell you not to do it, I reallized just now that it sounded that way, I just wanted to give you full knowledge of what you were going to be getting into.

  20. #20
    I lika da Chevy's LETHALxLS1's Avatar
    Join Date
    Oct 2006
    Location
    USA
    Posts
    5,328

    BLACK
    Z/28 LS1

    Quote Originally Posted by MechanicalMehem View Post
    Man I wasnt trying to tell you not to do it, I reallized just now that it sounded that way, I just wanted to give you full knowledge of what you were going to be getting into.
    No man I appreciate your help. I got surgery recently and I really shouldnt be fooling with stuff like that. I thought it was really cool of you to take your time to give me some insight. Thanks again!!!

Page 1 of 4 1234 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Rough Idle
    By thacher2189 in forum LT1
    Replies: 3
    Last Post: 02-19-2012, 03:04 PM
  2. Help: Rough Idle
    By 1WickedWS6 in forum GM Trucks
    Replies: 12
    Last Post: 01-04-2012, 08:16 AM
  3. Help: intermittant rough idle, off idle hesitation
    By Matto4785 in forum General Help
    Replies: 1
    Last Post: 09-21-2009, 06:12 AM
  4. Help: rough idle
    By RLamas in forum Firebird / WS6
    Replies: 8
    Last Post: 05-01-2009, 05:59 PM
  5. C5 Rough Idle
    By BlkNBlkC5 in forum Corvette
    Replies: 1
    Last Post: 04-14-2007, 07:42 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •