Page 1 of 2 12 LastLast
Results 1 to 15 of 17

Thread: Bucking under light throttle

  1. #1
    Join Date
    Jul 2021
    Location
    Memphis TN
    Posts
    17

    Bucking under light throttle

    UPDATE: MarauderJack had the winning guess. It was a vacuum leak in the EGR valve. Car runs great now!

    I have an 04 marauder with 170k on the clock. I just got it recently and combing through a few issues.

    Issue: When cruising in any gear, any speed, it will buck a decent amount until you let off or apply slightly more throttle. I'm talking the lightest of pedal touches just to maintain a speed on a flat road.

    All coil packs were replaced about 10k miles ago. I need to see what brand they are. The trans fluid was changed recently, and looks fine.

    Any ideas where I should start troubleshooting?
    Last edited by khamilton1; 10-11-2021 at 03:26 PM.

  2. #2
    Join Date
    Apr 2010
    Location
    South Florida
    Age
    31
    Posts
    1,752
    Have to get a scanner on it that reads the ignition coils while it's acting up.


    Sent from my iPhone using Tapatalk Pro

  3. #3
    Join Date
    Nov 2006
    Location
    Union City, CA
    Age
    46
    Posts
    2,461
    And you have tried just changing the spark plugs? That was my issue when I started getting some slight bucking.
    2003 Mercury Marauder 300B (Daily Driver)
    1988 LTD Crown Victoria S

  4. #4
    Join Date
    Jul 2021
    Location
    Memphis TN
    Posts
    17
    I need to see if my Torque phone app will read the coils. That is a good idea.

    88LTDCV351: As easy as they are to pull on these cars, I should just start there lol.

    I'm starting to suspect the trans though. A friend checked the dipstick and said it looked fine. I just checked it and the fluid is murky and the bottom of the dipstick is rusted and flakey about halfway up.... not a good sign.

  5. #5
    Join Date
    Nov 2014
    Location
    KC
    Age
    46
    Posts
    3,439
    40 bucks for cheap coils on eBay to diagnose the bucking…

    fixed mine
    The twins2.3 whipple/aluminatorVortech V-2 lots of goodies

    Current marauders
    04 DTR totaled JUST NOW starting to part out 7-21-2021 https://youtu.be/REUxjP1BVpg

    04 Silver Birch Dark Charcoal Hardtop Whipple Supercharger
    04 Silver Birch Dark Charcoal Hardtop V2 Supercharger
    04 Silver Birch Dark Charcoal Converted
    03 DBP Light Flint #122
    03 DBP Dark Charcoal #232
    03 Silver Birch 300b Light Flint Going to fix er up
    03 Black 300a
    04 Silver Birch Dark Charcoal moonroof in the works

    04 Heaton Swapped DTR
    Joe's Wrecked DTR rebuild thread

  6. #6
    Join Date
    May 2009
    Location
    Moreau Island
    Posts
    11,943
    Any codes?

  7. #7
    Join Date
    Oct 2003
    Location
    Beaufort, SC
    Posts
    7,708
    Mine was EGR Valve.......not expensive but not exactly a walk in the park to change if it's never been done!!
    No Marauder

  8. #8
    Join Date
    Aug 2011
    Location
    Wisconsin
    Posts
    4,229
    Check FRPS, that was my problem.

    WLB
    BB#1) 1996 ImpalaSS - 16,500 miles - 100% stock
    ______________________________ ___________

    BB#2) 2003 Marauder (300a) - 34k miles - Daily Driver
    #2912 of 7093
    Conceived 8/6/2002
    Delivered 9/19/2002
    Adopted 8/10/2011
    Trilogy 242 - Self Installed 9/9/12 (0-60 5.5 sec)
    Pioneer 6x8 Front
    Legacy 600w 6x9 Rears
    JL 6.5 SubWoofer
    K&N CAI
    Window tint 50% rear/35% front
    FBM CHMSL with Strobe mod 7/1/12
    DR Deep Aluminum Trans Pan
    Sparta FOMOCO Racing 8.8 Girdle
    Mo's Dyno Tune
    Gorilla Nuts - The System
    Ford Racing 4.10s, 31 spline Cobra carrier & axles 7/1/12
    Powder Coat Axle Housing 7/1/12
    CME HP Rear Control Arms & Watts Link 7/1/12
    ______________________________ ________________

    Rex "SC Cheesehead" Weinbender 11-14-13
    Ed "Baaad GN" Linthicum 8-6-2014

  9. #9
    Join Date
    Jul 2021
    Location
    Memphis TN
    Posts
    17
    No codes. Hoping to get to diagnosing this weekend. I'll post back when I get it tested

  10. #10
    Join Date
    Nov 2014
    Location
    KC
    Age
    46
    Posts
    3,439
    You won’t get codes for misfires immediately from what I understand. My car with bad coil was exactly what you are describing and I spent 40 bucks on eBay for cheap coils. That fixed the problem and I put 30k on them and totaled the car unfortunately
    The twins2.3 whipple/aluminatorVortech V-2 lots of goodies

    Current marauders
    04 DTR totaled JUST NOW starting to part out 7-21-2021 https://youtu.be/REUxjP1BVpg

    04 Silver Birch Dark Charcoal Hardtop Whipple Supercharger
    04 Silver Birch Dark Charcoal Hardtop V2 Supercharger
    04 Silver Birch Dark Charcoal Converted
    03 DBP Light Flint #122
    03 DBP Dark Charcoal #232
    03 Silver Birch 300b Light Flint Going to fix er up
    03 Black 300a
    04 Silver Birch Dark Charcoal moonroof in the works

    04 Heaton Swapped DTR
    Joe's Wrecked DTR rebuild thread

  11. #11
    Join Date
    Aug 2011
    Location
    Wisconsin
    Posts
    4,229
    No codes with my issue either

    WLB
    BB#1) 1996 ImpalaSS - 16,500 miles - 100% stock
    ______________________________ ___________

    BB#2) 2003 Marauder (300a) - 34k miles - Daily Driver
    #2912 of 7093
    Conceived 8/6/2002
    Delivered 9/19/2002
    Adopted 8/10/2011
    Trilogy 242 - Self Installed 9/9/12 (0-60 5.5 sec)
    Pioneer 6x8 Front
    Legacy 600w 6x9 Rears
    JL 6.5 SubWoofer
    K&N CAI
    Window tint 50% rear/35% front
    FBM CHMSL with Strobe mod 7/1/12
    DR Deep Aluminum Trans Pan
    Sparta FOMOCO Racing 8.8 Girdle
    Mo's Dyno Tune
    Gorilla Nuts - The System
    Ford Racing 4.10s, 31 spline Cobra carrier & axles 7/1/12
    Powder Coat Axle Housing 7/1/12
    CME HP Rear Control Arms & Watts Link 7/1/12
    ______________________________ ________________

    Rex "SC Cheesehead" Weinbender 11-14-13
    Ed "Baaad GN" Linthicum 8-6-2014

  12. #12
    Join Date
    Mar 2008
    Location
    Next door to my neighbor
    Age
    48
    Posts
    19,947
    About the only way you’ll get a misfire code on these cars is a 0-100 WOT non stop flight.


    Sent from my iPhone using Tapatalk Pro


    Cobra short block / ProCharger F1-A / Cog drive upgrade / Manley valves / Brian Tooley Racing valve springs / 80# inj. / -8 fuel line / -6 return / Aeromotive 340 pumps and regulator / 2012 GT500 TR6060 six speed / twin disc clutch / Driveshaft Shop GT500 upgraded CV joint shaft / BA5000 blow thru MAF/ 4.10's / Ford Racing 31 spline set up and Girdle / Metco D.S. safety loop / Stainless Works headers, cats, and everything else out back / ClassGlass hood / Bob's hood strut mod / Hurst line lock / Metco control arms / Addco front and rear sway bars / Monroe severe duty shocks all around / Race concepts rotors / Badgeless grille / 35% tint / FBM's interior LED kit and ambient lighting kit / Pioneer FB700 deck / kenwood speaker 4 Ch. / Rockford Fosgate 10" sub and amp / Kicker 6 X 8's all around / back up cam / bluetooth / Pioneer Xm / 704 RWHP 603 RWTQ tuned by Mo's Speedshop.

  13. #13
    Join Date
    Jul 2021
    Location
    Memphis TN
    Posts
    17
    I did pull a plug and they look brand new. Even have Dielectric grease on it. The new coils packs are Ford OEM. Previous owner took care of this car for sure. One interesting thing to note, I unhooked the battery and reset the computer this weekend. Now it has stopped bucking

    I'm sure it will be back. Next I'll check on the EGR and FRPS as mentioned, when I get time.

  14. #14
    Join Date
    Jul 2021
    Location
    Memphis TN
    Posts
    17
    I feel pretty stupid today. I have missed the forest for the trees. I was ready to do another leak down test on the vacuum, went to pull the intake tube and put a rubber glove on the throttle body and noticed the TPS sensor was unhooked! Hooked that back up and now everything appears to be normal. No more bucking. I hope that was all it was.

    Check the easy stuff first, folks lol.

  15. #15
    Join Date
    Sep 2008
    Location
    USA
    Posts
    2,361
    Cheap, easy fix.
    The best kind
    Ex Panther Owner

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 11
    Last Post: 12-03-2014, 10:58 PM
  2. Vortech s/c car with bucking at WOT
    By drhill in forum Power Adders
    Replies: 20
    Last Post: 12-19-2012, 12:12 AM
  3. Bucking
    By paSS in forum Shop Talk
    Replies: 11
    Last Post: 02-11-2012, 09:25 PM
  4. Engine bucking???
    By fairlane347 in forum Shop Talk
    Replies: 38
    Last Post: 07-30-2009, 05:46 PM
  5. Now a bucking 390 !!!
    By Thomas C Potter in forum The Classic Lounge
    Replies: 6
    Last Post: 05-10-2009, 06:39 PM

Posting Permissions

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