93 Eldorado
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 14 of 14
Northstar Engines and System Technical Discussion Discussion, 93 Eldorado in Cadillac Engine Technical Discussion; I have a 4.6L Northstar; it will not run at constant RPM at idle; periodically speeds up at idle stopped ...
  1. #1
    Dave Day's Avatar
    Dave Day is offline Cadillac Owners Member
    Join Date
    Sep 2005
    Posts
    2

    93 Eldorado

    I have a 4.6L Northstar; it will not run at constant RPM at idle; periodically speeds up at idle stopped in traffic and hard to brake; dealer says a bad ignition module but I have my doubts considering operating characteristics; almost indicative of bad gas (water)...anyone experienced this??

    Traction control system disabled with TO73 and PO93 codes. Starts rough until TCS Disable appears in IPC...

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,034

    Re: 93 Eldorado

    I'd first suspect and inspect the IAC (idle air control) valve on the side of the TB. Next, clean the TB if that hasn't been done in a while. Then check for vacuum leaks.

  4. #3
    JC316 is offline Cadillac Owners Connoisseur
    Automobile(s): 98 Seville SLS *Lord Vadar*
    Join Date
    Mar 2005
    Location
    DFW Texas
    Age
    28
    Posts
    1,403

    Re: 93 Eldorado

    Maybe the Idle Speed Control motor. It is located right under the cruise control module.

  5. #4
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,034

    Re: 93 Eldorado

    4.9 uses an ISC motor. The Northstar does not. It uses an ISC valve that meters bypass air around the throttle plate to control idle speed.

  6. #5
    eagleworks4u's Avatar
    eagleworks4u is offline Cadillac Owners Member
    Automobile(s): 1994 Eldorado Touring
    Join Date
    Nov 2004
    Location
    Ft Laud Fl
    Posts
    58

    Re: 93 Eldorado

    Check your codes for a possible map sensor problem codes p031,p071,p095. I thought my fuel pump was bad and it just was the map sensor under the intake manifold. Car runs perfect now

  7. #6
    JC316 is offline Cadillac Owners Connoisseur
    Automobile(s): 98 Seville SLS *Lord Vadar*
    Join Date
    Mar 2005
    Location
    DFW Texas
    Age
    28
    Posts
    1,403

    Re: 93 Eldorado

    Then what is that motor that is right under the cruise control? Autozone lists an idle speed control motor for a 4.6 in a 95 seville. What ever that thing is, it was causing my throttle to jump around.

  8. #7
    peteski is offline Cadillac Owners Enthusiast
    Automobile(s): 85 Eldo Biarritz
    Join Date
    Dec 2003
    Location
    Northeast USA
    Posts
    808

    Re: 93 Eldorado

    Ranger,
    93 N* Engine does use an ISC motor. I know, I own one. Yes, it is the motor under cruise control servo. It's plunger touches the throttle lever and controls idle speed.

    Peteski

  9. #8
    Krashed989's Avatar
    Krashed989 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 Eldorado, and a 99 ETC
    Join Date
    Sep 2004
    Location
    Hilo, Hawaii
    Age
    26
    Posts
    3,887

    Re: 93 Eldorado

    T073-----PCM - EBTCM/EBCM Pulse Width Modulation Signal Fault
    P093 (E093)-----Traction control system signals were not received by PCM

    Check your connections going to your EBTCM (Electronic Brake and Traction Control Module). The module is located in front of the tranny. Its easier to see it with the air filter box out of the way. There should be a few brake lines going into it and a large wiring harness. After you make sure the connection is tight, clear the codes and see if they come back after a test drive.

    The codes have nothing to do with your idle speed issue. Follow the other guys instructions on that, I think they pretty much said it all already.


    OHH yeah, by the way,

  10. #9
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,034

    Re: 93 Eldorado

    Quote Originally Posted by peteski
    Ranger,
    93 N* Engine does use an ISC motor. I know, I own one. Yes, it is the motor under cruise control servo. It's plunger touches the throttle lever and controls idle speed.

    Peteski
    Well I be dipped. Just when you think you know what your talking about. I guess they must have switched in '95 with the redesigned intake. Sorry for the misinformation.

  11. #10
    peteski is offline Cadillac Owners Enthusiast
    Automobile(s): 85 Eldo Biarritz
    Join Date
    Dec 2003
    Location
    Northeast USA
    Posts
    808

    Re: 93 Eldorado

    I think that you are correct Ranger.

    Peteski

  12. #11
    davesdeville's Avatar
    davesdeville is offline Banned
    Automobile(s): 1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
    Join Date
    Aug 2003
    Location
    Albuquerque, NM
    Age
    26
    Posts
    7,971

    Re: 93 Eldorado

    My 95 has an ISC motor. At least I could swear it does. Will check tomorrow when it's light out. I know it's a 95+ motor with the one piece intake manifold but it would be interesting to check the engine vin against the car's vin since there's junkyard writing on the front cam cover. I know I've seen it around here, but for the life of me I can't seem to find where the engine vin is located - anyone?

  13. #12
    peteski is offline Cadillac Owners Enthusiast
    Automobile(s): 85 Eldo Biarritz
    Join Date
    Dec 2003
    Location
    Northeast USA
    Posts
    808

    Re: 93 Eldorado

    Don't know where the VIN is.

    But I thought that when they redesigned the intake and started to use the MAF sensor, they also got rid of ISC. But I have a 93 Eldo, so I'm not sure.

    Peteski

  14. #13
    Dave Day's Avatar
    Dave Day is offline Cadillac Owners Member
    Join Date
    Sep 2005
    Posts
    2

    Re: 93 Eldorado

    Quote Originally Posted by Dave Day
    I have a 4.6L Northstar; it will not run at constant RPM at idle; periodically speeds up at idle stopped in traffic and hard to brake; dealer says a bad ignition module but I have my doubts considering operating characteristics; almost indicative of bad gas (water)...anyone experienced this??

    Traction control system disabled with TO73 and PO93 codes. Starts rough until TCS Disable appears in IPC...
    My 93 is a 4.6L, VIN 9, and it does have an idle speed motor. I just replaced it. Motor cost about $175.00 and is platinum coated with traces of gold!!! Spindle was gooked up and appeared not to respond properly on idle runaway.
    However, it didn't solve my idle problem but I think I also have ignition control module problems

  15. #14
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,034

    Re: 93 Eldorado

    Did you adjust it after installing it?

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting