« previous next »
Pages: [1]   Go Down

Author Topic: Weird revving  (Read 1286 times)

0 Members and 1 Guest are viewing this topic.

Offline jfrabat

  • Gargantuan Mango Tree MechanicŪ
  • Member
  • *
  • Posts: 3676
  • Finally USING the Jeep!
Weird revving
« on: February 01, 2010, 08:47:19 PM »
I got to Panama again, and my Jeep has a new symptom; if I am sitting letting it idle, and (in neutral) I floor the accelarator, it stuters (sp?) a bit and then revs...  It feels like there is too much fuel for the ignition or something, but then it catches on.  This will also happen if I floor it on a gear from low RPMs.  Any idea what this could be?
Logged
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

Offline sharpxmen

  • Chief Squirrel BlowerŪ
  • Member
  • *
  • Posts: 7093
Re: Weird revving
« Reply #1 on: February 01, 2010, 09:07:07 PM »
maybe FPR/fuel pump, map, tps, o2

i don't think it's ignition since you said you changed (if i remember correctly) pretty much everything after the engine washing incident.
Logged
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline Jeffy

  • Administrator
  • Member
  • Posts: 14955
Re: Weird revving
« Reply #2 on: February 01, 2010, 09:49:14 PM »
Quote from: jfrabat on February 01, 2010, 08:47:19 PM
I got to Panama again, and my Jeep has a new symptom; if I am sitting letting it idle, and (in neutral) I floor the accelarator, it stuters (sp?) a bit and then revs...  It feels like there is too much fuel for the ignition or something, but then it catches on.  This will also happen if I floor it on a gear from low RPMs.  Any idea what this could be?
Why are you going WOT from an idle in neutral?

Sounds normal.  You've dumping a bunch of fuel into the engine before it's able to spin up.  Do that on a carbed engine and you'll usually get the same thing.
Logged
Youtube Channel: https://www.youtube.com/channel/UCZNlr60GXH5OlKIFrT7P6mg
My Jeep: http://4bangerjp.com/forums/index.php?topic=2783.0
"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

Offline sharpxmen

  • Chief Squirrel BlowerŪ
  • Member
  • *
  • Posts: 7093
Re: Weird revving
« Reply #3 on: February 02, 2010, 12:14:44 AM »
Quote from: Jeffy on February 01, 2010, 09:49:14 PM
Why are you going WOT from an idle in neutral?

Sounds normal.  You've dumping a bunch of fuel into the engine before it's able to spin up.  Do that on a carbed engine and you'll usually get the same thing.

it shouldn't stutter (at least i don't recall having that issue) - first thought FPR, i'm thinking it doesn't reduce the pressure at idle it won't give the extra boost of fuel when suddenly open the throttle, not sure though
Logged
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline Jeffy

  • Administrator
  • Member
  • Posts: 14955
Re: Weird revving
« Reply #4 on: February 02, 2010, 01:32:30 PM »
Quote from: sharpxmen on February 02, 2010, 12:14:44 AM
it shouldn't stutter (at least i don't recall having that issue) - first thought FPR, i'm thinking it doesn't reduce the pressure at idle it won't give the extra boost of fuel when suddenly open the throttle, not sure though
There will be a slight delay and usually a slight drop in RPM before it revs up.
Logged
Youtube Channel: https://www.youtube.com/channel/UCZNlr60GXH5OlKIFrT7P6mg
My Jeep: http://4bangerjp.com/forums/index.php?topic=2783.0
"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

Offline jfrabat

  • Gargantuan Mango Tree MechanicŪ
  • Member
  • *
  • Posts: 3676
  • Finally USING the Jeep!
Re: Weird revving
« Reply #5 on: February 02, 2010, 03:17:51 PM »
Quote from: Jeffy on February 02, 2010, 01:32:30 PM
There will be a slight delay and usually a slight drop in RPM before it revs up.

The I guess it's NOT acting weird...
Logged
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

Offline Jeffy

  • Administrator
  • Member
  • Posts: 14955
Re: Weird revving
« Reply #6 on: February 02, 2010, 03:24:19 PM »
I'd gonna guess it's almost like when you're about to stall it and the PCM catches it and revs the engine to 1000 RPM.
Logged
Youtube Channel: https://www.youtube.com/channel/UCZNlr60GXH5OlKIFrT7P6mg
My Jeep: http://4bangerjp.com/forums/index.php?topic=2783.0
"If the motor car were invented today, there is absolutely no way that any government in the world would let normal members of the public drive one."

Offline jfrabat

  • Gargantuan Mango Tree MechanicŪ
  • Member
  • *
  • Posts: 3676
  • Finally USING the Jeep!
Re: Weird revving
« Reply #7 on: March 03, 2010, 08:26:49 AM »
Quote from: Jeffy on February 02, 2010, 03:24:19 PM
I'd gonna guess it's almost like when you're about to stall it and the PCM catches it and revs the engine to 1000 RPM.

Well, the issue got worse, and all of the sudden, I got a code.  It seems that the TPS plug wiggled itself loose (the safety clip broke some time ago), and this is what was causing the problem.  I actually got scared that the Jeep was breaking down on me, and I would not be able to drive it to Costa Rica, but it was a simple fix (plug the connector back in), so I guess I am still taking the drive...

I think I will use some electrical tape to tape the connector in place and avoid this from happening again.
Logged
'94 YJ 2.5L with 4" RE lift, Superwinch EPi9.0, FoMoCo e-Fan, SD30 and SD35 w/ARB-5.13, 165A alt., 33" BFG KM2 on 15" AR wheels, Sony sound system, Pavement Ends Hardtop, Hydroboost

Offline sharpxmen

  • Chief Squirrel BlowerŪ
  • Member
  • *
  • Posts: 7093
Re: Weird revving
« Reply #8 on: March 03, 2010, 08:49:55 AM »
Quote from: jfrabat on March 03, 2010, 08:26:49 AM
Well, the issue got worse, and all of the sudden, I got a code.  It seems that the TPS plug wiggled itself loose (the safety clip broke some time ago), and this is what was causing the problem.  I actually got scared that the Jeep was breaking down on me, and I would not be able to drive it to Costa Rica, but it was a simple fix (plug the connector back in), so I guess I am still taking the drive...

I think I will use some electrical tape to tape the connector in place and avoid this from happening again.

use a drop of rtv on the connector plastic part that goes in the tps sensor - that should keep it in place.
Logged
'95 YJ, NSG370 6spd / Hurst shifter, Dana 300 + 4:1 Doubler / tri-stick, Custom skid, Super D35 / Auburn LSD / 4.88, 35x12.5x15 BFG KM2, 64mm t/b, 1.7 RollerRockers, MkVIII e-fan, Dual Diaph Booster
Latest: Corbeau BajaRS heated seats :dance: keeping warm the rear end

Offline chardrc

  • Member
  • Posts: 3535
Re: Weird revving
« Reply #9 on: March 03, 2010, 03:48:58 PM »
hot glue gun can fix that.. or atlaest that's what they do with computers at some places..
Logged
1990 YJ 4cly, ax5, 2.5 inch BDS lift, 31 MTr\'s,  Powertrax-lockers all around, track-bars removed, boomerang shackles, warn m8000 winch, electric fan. [sold but not forgotten]

2007 jk Rubicon 2dr
Pages: [1]   Go Up
« previous next »