1988 Slight backfire 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 11 of 11
Cadillac Allante Forum Discussion, 1988 Slight backfire under acceleration in Past Cadillac Vehicle Discussion; As I mentioned in a previous post, just purchased a 1988 Allante. Car is in great shape, starts easy, runs ...
  1. #1
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    1988 Slight backfire under acceleration

    As I mentioned in a previous post, just purchased a 1988 Allante. Car is in great shape, starts easy, runs great...with one exception...there is a slight backfire (pop) under acceleration. Sounds like just one cylinder missing sometimes. I do not know the history on this car. Is this a common problem and is there something I should look at first?

    Thanks for your help!
    Bill

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    carnut is offline Cadillac Owners Master
    Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
    Join Date
    Feb 2003
    Location
    california
    Age
    66
    Posts
    5,471

    Re: 1988 Slight backfire under acceleration

    Pop from under hood or from the tail pipe? From the tail pipe I would suspect plug wires. Are we talking about quick acceleration? A series of pops?

  4. #3
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    Re: 1988 Slight backfire under acceleration

    Quote Originally Posted by carnut View Post
    Pop from under hood or from the tail pipe? From the tail pipe I would suspect plug wires. Are we talking about quick acceleration? A series of pops?
    Its from the tail pipe. It does it even under "moderate" acceleration, you have to be very gentle to not have it pop. It is a series of pops but separated by time such that I think its only one cylinder. You think its the plug wires? I was kind of thinking maybe a fuel injector that wasn't closing all the way or maybe a sticking valve. Plug wires would be easy to start with.

    Thanks, Bill

  5. #4
    MoistCabbage's Avatar
    MoistCabbage is online now Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    18,641
    Yeah, a "backfire" from the tailpipe is called a "muffler report". It's caused by fuel vapor in the exhaust. Either too much fuel is being injected (faulty FPR, stuck injector...), or there's a misfire.

  6. #5
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    Re: 1988 Slight backfire under acceleration

    Thanks guys. Is there a preferred Spark Plug brand/type that works the best with these engines?

  7. #6
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    Re: 1988 Slight backfire under acceleration

    Along with Spark Plug brand/type... Is there a procedure somewhere on how to best get to the rear spark plugs to change them?

  8. #7
    carnut is offline Cadillac Owners Master
    Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
    Join Date
    Feb 2003
    Location
    california
    Age
    66
    Posts
    5,471

    Re: 1988 Slight backfire under acceleration

    I used the Delco plugs designed for a 91 4.5 Eldo. platinum so they go 90,000 miles. When I did mine, I removed the 2 front sub frame bolts and lowered the engine slightly with a floor jack to gain more rear access. Plan on wires, They will be stuck on the plugs!

    ----------

    Fuel pressure regulator is rather uncommon to fail on this engine. With the service manual instructions, you can short out each cylinder thru on board diagnostics to isolate which cyl is acting up.

  9. #8
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    Re: 1988 Slight backfire under acceleration

    Thanks Carnut. I hope I can figure out which 2 bolts to remove. Is it obvious?

    I ordered AC Delco platinum plugs, wires and cap/rotor from Rockauto...just waiting for delivery and time to work on it. Also just ""won" an eBay bid for a factory 1988 service manual. yea!

  10. #9
    carnut is offline Cadillac Owners Master
    Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
    Join Date
    Feb 2003
    Location
    california
    Age
    66
    Posts
    5,471

    Re: 1988 Slight backfire under acceleration

    2 large bolts holding the front of the sub frame holding the engine! Be careful. Dont hit the fan with the engine.

  11. #10
    ncpi is offline Cadillac Owners Member
    Automobile(s): Allante
    Join Date
    Jun 2013
    Posts
    11

    Re: 1988 Slight backfire under acceleration

    BTW. New platinum plugs, wires, distributor cap and rotor did the trick! I guess after 25 years, they needed replacing

  12. #11
    carnut is offline Cadillac Owners Master
    Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
    Join Date
    Feb 2003
    Location
    california
    Age
    66
    Posts
    5,471

    Re: 1988 Slight backfire under acceleration

    Thanks for the update. This will help someone else.

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