Jump to content
CaddyInfo Cadillac Forum

04 Deville struggling to accelerate


Recommended Posts

Long story short, a mechanic that I no longer use decided to power wash my engine after changing the oil pan/valve cover gaskets, and now my caddy struggles terribly. When it idles, the car jumps around, when accelerating from a stop, the car struggles to get up to 30-40mph. I am receiving a code P0354, which is misfire #4, but the coil and plug appears to be fine. I had a huge rip in the manifold coupling, so I changed that as well. 

Can anyone assist me in finding out what's wrong with my vehicle?

Link to comment
Share on other sites


Not to be confused with p0304.....p0354 is a different code...

 

The ignition system uses individual ignition coil/module assemblies for each cylinder. The powertrain control module (PCM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. The PCM monitors each IC circuit for improper voltage levels. Each ignition coil/module has the following circuits:

    •  An ignition voltage circuit

    •  A ground

    •  An IC circuit

    •  A low reference circuit

If the PCM detects a failure on the IC circuit of the ignition coil/module, it will set 1 of the corresponding DTCs:

    •  DTC P0351 for ignition coil/module 1

    •  DTC P0352 for ignition coil/module 2

    •  DTC P0353 for ignition coil/module 3

    •  DTC P0354 for ignition coil/module 4

    •  DTC P0355 for ignition coil/module 5

    •  DTC P0356 for ignition coil/module 6

    •  DTC P0357 for ignition coil/module 7

    •  DTC P0358 for ignition coil/module 8

 

#4 is front of engine....2nd one in from passenger side. The 2004 uses individual ignition coils for each cylinder.

Link to comment
Share on other sites

Once you repair the problem on #4, if the engine still struggles, check for a clogged cat.  A single misfiring or dead cylinder shouldnt cause the engine to struggle as you describe.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

On 1/7/2017 at 0:06 PM, BodybyFisher said:

Once you repair the problem on #4, if the engine still struggles, check for a clogged cat.  A single misfiring or dead cylinder shouldnt cause the engine to struggle as you describe.

Does it maybe sound like the MAF sensor?

Link to comment
Share on other sites

It NEVER "sounds" like anything.  You have an on-board diagnostic system that runs tests and when something is wrong, it sets a trouble code.  If there is NO trouble code, there is no trouble....

However, there a few problems that won't set a code in all cases such as the fuel pressure regulator clogged cats, fuel pressure (it may set a lean code). 

Please post ALL your codes.  That will help us know what is going on.

Refer to my signiture here for how to check for codes, post all P and B codes.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

With the high pressure spray.....sounds like he may have gotten water down into the spark plug wells.....you would have to pull each coil and check.

Link to comment
Share on other sites

I missed that the engine was powerwashed or steam cleaned, sorry.  

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

  • 7 months later...

Well I know I have a high voltage code to the pcm have not figured it out yet but I know it ran great before I had to take the tranny out I think its in the main wire harness that runs in between eng and tranny major miss fire is the problem

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...