'99 engine stumble
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 6 of 6
Cadillac DeVille 1985 to 2005 including:
1985-1992 Fleetwood, 1993 Sixty Special, All FWD Forum Discussion, '99 engine stumble in Past Cadillac Vehicle Discussion; Just bought a beautiful pearl white Deville with unknown history with a nasty engine stumble; not a 'miss', but a ...
  1. #1
    Harry Yarnell is online now Cadillac Owners Fanatic
    Automobile(s): 2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
    Join Date
    Dec 2004
    Location
    perryman, MD
    Age
    70
    Posts
    498

    '99 engine stumble

    Just bought a beautiful pearl white Deville with unknown history with a nasty engine stumble; not a 'miss', but a chuggle just short of stalling while driving. In neutral, it throttles up just fine, and it starts instantly. When I say it's not a 'miss', I mean the stumble is erratic, as a miss is cyclical. A code 131( O2 sensor) is set, but this all is happening before it goes closed loop, so I don't think that comes into play. Here's what I've done: changed fuel filter, fuel pressure is 46#, glass beaded all 8 plugs, though they looked fine, measured resistance of all 8 wires; all within spec, swapped out ignition module. No change. Thinking of swapping PCM, but isn't there some reprograming required to do this?...and what is it? Anyone got some other ideas?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Submariner409's Avatar
    Submariner409 is offline If it won't run, stick on fender vents
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    75
    Posts
    45,950

    Re: '99 engine stumble

    Clean the coils, connectors, contacts, ICM and the ICM ground cable terminals. How old are the plug wires ? Time for a new AC Delco wireset. Use the pre-2000 plug wire diagram in my albums to make sure the proper coil tower is connected to the proper plug.

  4. #3
    Harry Yarnell is online now Cadillac Owners Fanatic
    Automobile(s): 2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
    Join Date
    Dec 2004
    Location
    perryman, MD
    Age
    70
    Posts
    498
    Thread Starter

    Re: '99 engine stumble

    As a follow up to this issue, seems it was TWO problems; one may have caused the other. Glass beaded the existing plugs (they looked good before). no help. REPLACED the plugs with new platinum AC's, and the miss (chuggle) was sorta gone, but it had no power; the more you gave it throttle , the more it bogged down, Shifting was also late. Suspect a clogged cat. Up on the lift, and you couldn't get near the cat, as it was so hot. Disconnected the four nuts holding the cat to the header pipe, and a test drive showed it would go like a scalded cat (pun intended). Oh, BTW, the dealer wants $100 to reprogram a replacement computer. As to the code 131, they mention a O2 sensor lean condition in bank 1. Which is bank 1? Front or rear?

  5. #4
    Submariner409's Avatar
    Submariner409 is offline If it won't run, stick on fender vents
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    75
    Posts
    45,950

    Re: '99 engine stumble

    Eastern Catalytic drop-in and a pipe clamp.

  6. #5
    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
    74,779

    Re: '99 engine stumble

    Bank 1 is the rear bank.

  7. #6
    Harry Yarnell is online now Cadillac Owners Fanatic
    Automobile(s): 2005 XLR, '96 eldo,'95 eldo,' 89 eldo,'78 eldo,'11CTS-V
    Join Date
    Dec 2004
    Location
    perryman, MD
    Age
    70
    Posts
    498
    Thread Starter

    Re: '99 engine stumble

    This clogged cat reminds me of a similar situation years ago with a '74 Cadillac hearse. This vehicle wouldn't get out of its own way, the shifts were late and there was this wheezing sound coming from the exhaust. Back then GM was using a double walled exhaust pipe on some models , why, I don't know, but the inner pipe (or wall) had pulled away from the outer pipe and coiled up like a pretzel inside, effectively closing it off. I don't remember how I discovered that, but I cut out that section of pipe for show and tell...

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