'92 Deville 4.9 runs great at startup, runs like crap when hot
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 4 of 4
HT4100 4.1, 4.5, 4.9 Discussion, '92 Deville 4.9 runs great at startup, runs like crap when hot in Cadillac Engine Technical Discussion; When we turn the car on, it runs smooth and nicely. After it warms up,it runs like a bag of ...
  1. #1
    Bluenose1 is offline Cadillac Owners Member
    Automobile(s): 97 Seville STS
    Join Date
    Nov 2006
    Posts
    22

    '92 Deville 4.9 runs great at startup, runs like crap when hot

    When we turn the car on, it runs smooth and nicely. After it warms up,it runs like a bag of crap. The code set is E30 - ISC RPM Out Of Range.
    Where would you start to troubleshoot this issue? Thermostat? EGR? Other?
    Any and all help appreciated.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    awadecki is offline Cadillac Owners Enthusiast
    Automobile(s): 76 Eldo (54k), 76 Eldo (52k), 78 Eldo (9k), 85 Deville (43k)
    Join Date
    Jun 2005
    Location
    Michigan
    Posts
    668

    Re: '92 Deville 4.9 runs great at startup, runs like crap when hot

    EGR is probably sticking and the ISC is trying to compensate by raising the idle. I'd start there.

  4. #3
    Bluenose1 is offline Cadillac Owners Member
    Automobile(s): 97 Seville STS
    Join Date
    Nov 2006
    Posts
    22

    Re: '92 Deville 4.9 runs great at startup, runs like crap when hot

    Replaced the EGR, now runs poorly from startup.

  5. #4
    aaronrus is offline Cadillac Owners Member
    Join Date
    Dec 2003
    Posts
    13

    Re: '92 Deville 4.9 runs great at startup, runs like crap when hot

    Quote Originally Posted by Bluenose1 View Post
    When we turn the car on, it runs smooth and nicely. After it warms up,it runs like a bag of crap. The code set is E30 - ISC RPM Out Of Range.
    Where would you start to troubleshoot this issue? Thermostat? EGR? Other?
    Any and all help appreciated.
    i wouldnt replace the EGR unless you replace it with a delco part, MOST aftermarket EGRs are crap.. just plug the vacuum line going to the egr with a golf tee for now to eliminate it as a possibility...

    if the car is running liek crap after it warms up, that means you have a bad sensor somewhere most likely...a bad isc motor is just gonna make it idle high or low...have you ever replaced the O2 sensor(s) on the car? i would start there if they are the original O2 sensors, its time to replace them anyways if they are the orginal..

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