96 Deville won't idle down, hard start and backfires when cold - Page 3
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
Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast
Results 31 to 45 of 70
Northstar Engines and System Technical Discussion Discussion, 96 Deville won't idle down, hard start and backfires when cold in Cadillac Engine Technical Discussion; The shocks in the link in post #29 are for converting active to passive. You do not need that on ...
  1. #31
    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
    72,966

    Re: 96 Deville won't idle down, hard start and backfires when cold

    The shocks in the link in post #29 are for converting active to passive. You do not need that on a '96 base Deville. You already have passive suspension. All you need is regular shocks with air.

    http://www.amazon.com/Monroe-40046-R...ype=automotive

  2. #32
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Help me out here, Ranger. My 94 Deville had me baffled, too. It, like my current 96, had wires coming from the shocks and struts. What are those wires for if the shocks aren't electronic, and what do I do with them?

    Dropping 96 off at transmission shop tonight. $765 labor to change that turbine speed sensor. Wiring harness looks like new. Financially, I'd have been better off leaving this car where I found it. But, it'll be a heck of a nice car and surely dependable after this initial beating, so what the hell... Why not. Better than paying top dollar for a car you believe to need nothing and then getting walloped.

  3. #33
    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
    72,966

    Re: 96 Deville won't idle down, hard start and backfires when cold

    If you have wires to the shocks then you must have a special ordered car with the CVRSS option (active suspension). That being the case, disregard post #31.

  4. #34
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Toward the bottom of the shocks, facing in, there's a tube with wires coming out. My 94 was a base with the 4.9L engine and it also had wires coming from the shocks and struts. Never had to monkey with them, though, cause they all worked.

  5. #35
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Pulled an IAC valve from the junkyard. No effect on idle issue. Warmer and humid here now, and car exhibits high, surging idle issue upon every cold start. Learned a little trick, though. If I shut the engine off and restart it 3 times, it will idle and run fine until it sits and cools off again. Any thoughts?

  6. #36
    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
    72,966

    Re: 96 Deville won't idle down, hard start and backfires when cold

    I'm still leaning towards a vacuum leak.

  7. #37
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Intake gaskets are cheap...

  8. #38
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Just talked to a friend at a Chevrolet dealership, and he advised me to grab a junkyard MAFS and see if that makes a difference. Apparently they had some trouble with them boogering up and not throwing codes in the past.

  9. #39
    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
    72,966

    Re: 96 Deville won't idle down, hard start and backfires when cold

    Never heard of that, but certainly a possibility and can't hurt.

  10. #40
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Where's this at: Code IP2128 Throttle/Pedal Pos Sensor/Switch E Circ High Input

  11. #41
    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
    72,966

    Re: 96 Deville won't idle down, hard start and backfires when cold

    IP is not a code. It means Instrument Panel. You probably mean P2128 - Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage. I've heard of a TPS (Throttle Position Sensor), but never heard of that sensor.

  12. #42
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    It's the category directly after PMC. The code reads IP2128, which I couldn't find a definition for anywhere. The few times one does see that code in a Google search, the "I" us dropped, leaving P2128, which is the accelerator peddle sensor.

    It was in the history, and it's obviously not common, so it's probably nothing.

    Anyway, my throttle issue seems to have pretty well resolved itself. Since I went to the junkyard and picked up another MAF sensor, the car hasn't acted up. Must have scared it or something.

    Now I'm down to an annoying "door open" alarm, which I believe I've narrowed down to the front passenger door latch. And also a clunky air compressor throwing an exhaust valve code, which is getting addressed this morning.

  13. #43
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    44,199

    Re: 96 Deville won't idle down, hard start and backfires when cold

    The ELC exhaust valve code will probably turn out to be a damaged solenoid control head on the compressor - that system supplies and vents air to/from the shock bladders to control ride height. The head gets gunked up with watery snot from carryover due to an overloaded filter-dryer canister. Replace the entire compressor/control head/filter-dryer assembly. The Suncore website.

  14. #44
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    I got a new compressor from Arnott. They seem like a good company to deal with. A few shops here locally highly recommend them. Didn't get the compressor changed out. Mechanic had a death in the family this morn. I really need a lift, even if it's out in the weather

  15. #45
    magistrate_apeman is offline Cadillac Owners Member
    Automobile(s): 1996 Deville Base
    Join Date
    Sep 2011
    Posts
    42
    Compressor is on and works swell. No air leaks. Do have an rsoo28 code, hoping it's a wire.

    In other news, my throttle body began sticking a few days ago. Tore it all apart and cleaned it last night and installed new gaskets. No more sticky accelerator, but now my high idle issue is back to square one - not idling down below 1500 rpms, just like the day after I brought it home. Last night, after it began idling high again, I swapped the iac valve out again and it idled down to normal. This morning, the temperature dropped to 23 from 45 last night, and now it refuses to idle below 1500. Cycling the ignition and removing wires from components has zero effect. Sooo, I've got a brand new iac valve on the way, even though I'm convinced it won't fix the issue. After that, not sure what to do other than have the intake manifold gaskets changed.

    Grey hairs are sprouting at an alarming rate. For two weeks the thing ran perfect and it was wonderful. Why isn't it throwing a doggone code?! Show me a frickin sign already.... This issue is posted all over the net, but no one seems to have a solution.

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