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Author Topic: Weird revving  (Read 968 times)

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Offline jfrabat

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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?
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Offline sharpxmen

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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.
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Offline Jeffy

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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.
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Offline sharpxmen

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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
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Offline Jeffy

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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.
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Offline jfrabat

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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...
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Offline Jeffy

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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.
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Offline jfrabat

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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.
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Offline sharpxmen

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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.
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'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

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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..
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