'94 N* runs lumpy - hesitates. Any ideas?

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds

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 2 of 2
Northstar Engines and System Technical Discussion Discussion, '94 N* runs lumpy - hesitates. Any ideas? in Cadillac Engine Discussion; My '94 Concours pulls fine on hard accelleration, idles smoothly, but when just cruising along the engine seems "lumpy" or ...
  1. #1
    Andrew M. Franklin is offline Cadillac Owners Member
    Join Date
    Dec 2003

    '94 N* runs lumpy - hesitates. Any ideas?

    My '94 Concours pulls fine on hard accelleration, idles smoothly, but when just cruising along the engine seems "lumpy" or like it hesitates while cruising regardless of cruising speed or which gear the trans is in. At first I thought it felt like the TC was going in and out of lock. but now seems more engine related. No codes. Fresh plugs. Only does this about half the time and seems unrelated to whether the engine is cool or warm or hot. Has anyone any suggestions about what I might check? THanks. Sincerely, ANdy.

  2. Remove Advertisements

  3. #2
    Anthony Cipriano is offline Cadillac Owners Fanatic
    Automobile(s): 2004 Cadillac Escalade
    Join Date
    Jan 2003
    South Florida

    Re: '94 N* runs lumpy - hesitates. Any ideas?

    Go to the search feature of the forum toolbar and type "phenolic spacer plates" into the drop down box and read the posts.

    The 93/94 Northstar engines have the EGR delivery passages in the phenolic spacer plates that isolate the intake manifold from the cylinder heads and when those become plugged with carbon at high miles they can cause a maldistribution of EGR to the individual intake ports and can cause a reduction in overall EGR flow that causes a lean condition. Either could be the cause of the driveability problem. Simple fix is to clean the phenolic spacer plates.

  4. Remove Advertisements
    Cadillac Forums

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

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

Please enter a valid email address for yourself.

What Cadillac(s) do you own? (Or type NONE)

Please select your insurance company (Optional)

Your date of birth and age are displayed in several places on the forum. Only the administrator will have access to your date of birth should you choose to hide it via the privacy option below.


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.


Cadillac Posting Rules

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