'98 Deville Rough Idle, Shaking, Stuttering Under Acceleration
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 10 of 10
Northstar Engines and System Technical Discussion Discussion, '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration in Cadillac Engine Technical Discussion; I have a '98 Deville that seems to be misfiring. About 1 year ago, the devilel started throwing codes indicating ...
  1. #1
    Wxman is offline Cadillac Owners Member
    Join Date
    Apr 2005
    Posts
    2

    '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    I have a '98 Deville that seems to be misfiring. About 1 year ago, the devilel started throwing codes indicating a misfire in one of the cylinders. I changed the plugs and wires and it became much less frequent. I got cheap wires and went against the advice to use AC Delco since they were so expensive. Well the sputter is back and worse (but no codes). On rainy days, it sputters a lot. The car will idle rough and is clearly misfiring. Under hard acceleration, you can feel that all cylinders are not firing properly be the stuttering. If you floor it, it will shake and then you can feel a burst of power here and there when it starts to fire properly, then when it shifts gears it bogs hard.

    Any suggestions? Would it be worth it to change the wires again to AC Delco? Could that be the cause of the problem? Any way to diagnose the problem without going to a shop? Is there a way to deteremine if it is an ignition problem? By the way, it does not throw a check engine light now.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    powerglide's Avatar
    powerglide is offline Cadillac Owners Connoisseur
    Join Date
    Sep 2003
    Location
    Hermosa Beach, CA
    Posts
    2,726

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    My 98 deville showing same problems, we're trying to work through it now on my thread. You can follow it at:

    http://www.cadillacforums.com/forums...ad.php?t=36384

  4. #3
    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
    72,236

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Try misting the wires in a dark place at night. That might give an indication if you see the wires arching. It didn't work for me, that's why I said might. I have heard (as you) many people say stay away from after market wires. Let us know what the outcome is. Curious minds want to know.

  5. #4
    powerglide's Avatar
    powerglide is offline Cadillac Owners Connoisseur
    Join Date
    Sep 2003
    Location
    Hermosa Beach, CA
    Posts
    2,726

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Wxman, it may be ignition coils like in my case. I had to replace a second one today. The good news is its real easy to check, all you need is a multimeter.

    Goto the iginition coil (pictured in my thread), remove the two plug wires going to it and measure the resistance, should read between 5-10.

    If you go through and check all four of the ignition coils like that, you may find that one of them read very differently than the others.

    Still could be your plugs, wires, fule rail etc, but this is a real quick check and the repair couldnt be simpler.

    post back your findings when you get a chance.

    good luck

  6. #5
    eldorado1 is offline Cadillac Owners Connoisseur
    Join Date
    Feb 2004
    Location
    FL
    Posts
    2,250

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    If you replaced the plugs and wires, even the cheapest chinese-sweatshop made ones will work. Maybe with more crosstalk than normal, but they should not cause misfiring...

    Quote Originally Posted by powerglide
    Wxman, it may be ignition coils like in my case.
    I'd definately start there.

  7. #6
    BeelzeBob's Avatar
    BeelzeBob is offline I'm a Cadillac Fanatic!
    Join Date
    Dec 2002
    Location
    Fort Lauderdale, Florida
    Age
    49
    Posts
    9,577

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Quote Originally Posted by eldorado1
    If you replaced the plugs and wires, even the cheapest chinese-sweatshop made ones will work. Maybe with more crosstalk than normal, but they should not cause misfiring...



    I'd definately start there.

    This is not true. Cheap wires (and some expensive ones) will not work correctly from the very beginning due to electro-magnetic interference with the rest of the ignition system. The low voltage wiring from the crank sensors runs to the coil pack directly below the secondary ignition wires. If the wires leak current or cause EMI the signals will foul the crank sensor input from the crank sensors to the ignition module and cuase even more problems. Just because wires are new does not in any way guarantee that they are not the source of a miss or driveability problem. The OEM wires are not necessarily the only ones that will work but they are the only ones that are GUARANTEED to work because they were developed and tested on that particular application. Generic wires are just that....generic. They are made close to the correct length (if you are lucky) and that is about the extent of the testing and validation of them on that package. YOU are doing the testing and validation.

  8. #7
    eldorado1 is offline Cadillac Owners Connoisseur
    Join Date
    Feb 2004
    Location
    FL
    Posts
    2,250

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Get the OEM wires from some place you can return them.... Install them, see if there's any change. If not, it's not the wires, if so, keep them, and I'll eat dirt.

    But seriously, I'd really be interested in your results... All my cars have the cheap-o generic autozone wires on them, but I can't say that I haven't had any problems - I've had some suspicions, but am way too cheap to buy the OEM wires.. But if it fixes the problem, it might just provide the kick in the pants I need.

  9. #8
    Rick94STS's Avatar
    Rick94STS is offline Cadillac Owners Member
    Join Date
    Apr 2005
    Location
    New Jersey
    Posts
    31

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    last year my 94 STS starting running bad, I replaced everything: plugs, wires, O2 sensors, etc.....
    My mechanic scanned it and came up with nothing useful. He did suggest to try replacing the fuel pressure regulator. As i was beginning to dismantle the top of the intake to get to the regulator I found my fuel injector harness melted on the top of the trans housing causing two injector wires to short against the trans (ground). I repaired the melted wire harness and tie wrapped it up away from the trans.
    Car has ran perfect ever since then.

    Check your injector harness........

  10. #9
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Rick, my brother had the same thing happen on his 94 SLS. It gave him different problems. It ran bad but gave a MAP sensor code that didn't diagnose right. The insulation was coming off all the wires just above the connector by the trans

  11. #10
    Cruella Deville 96 is offline Cadillac Owners Member
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    2

    Re: '98 Deville Rough Idle, Shaking, Stuttering Under Acceleration

    Dear Gentlemen, bbob is right. As an Electronic Engineer, his explanation is right on the mark.

    I just changed plugs and wires in my '96 Deville, and found fresh oil dripping off of one of the front sparkplug ceramic insulators! Obviously, the minimum-wager at Jiffy-lube has done it to us again. When filling with oil, some got onto the heads, seeped down into the sparkplug well, and just sat there...waiting for a current to short to the block.

    This is my second post to this group, and even though I have the factory shop manuals, We, my wife and I, have learned so much!!!

    Thank You!

    Only use AC Delco wires and plugs. Mr. Goodwrench was right after all.
    Scott in Anchorage.

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