Author Topic: how come my 95 jeep is bogging down?  (Read 8521 times)

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95yjzilla

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how come my 95 jeep is bogging down?
« on: April 18, 2011, 05:52:39 PM »
i have a 95 jeep wrangler with a 2.5L. i was driving it last night and it started to bog down when its at about half throttle. It idles fine. I do have low voltage in my battery. wat do you guys think it can be?

Offline sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #1 on: April 18, 2011, 06:52:44 PM »
i have a 95 jeep wrangler with a 2.5L. i was driving it last night and it started to bog down when its at about half throttle. It idles fine. I do have low voltage in my battery. wat do you guys think it can be?

it's been reported before to be TPS or O2 but of course these are assumptions, could be other things like ignition (CPS, cap, rotor, wires, plugs) or fuel delivery (pump, filter, FPR, pressure/flow) related.
'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

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #2 on: April 19, 2011, 07:11:05 AM »
its pretty much trial and error then to really figure wat parts or parts need to be replaced

Offline sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #3 on: April 19, 2011, 08:06:03 AM »
its pretty much trial and error then to really figure wat parts or parts need to be replaced

usually you get a code, but in your case i take it the CEL did not come on. CPS would most likely give you problems at various rpm and loads, so that would narrow down the search a bit more but still - hard to tell for sure though with almost no data other than a brief description, you could start by visually checking the ignition components, then check the fuel pressure while you reproduce the issue and take it from there. You can also test the TPS output  with a multimeter, should go between 0.6v to close to 5v (can't remember the range exactly) the more important thing is to have it vary the output smoothly with no jumps while you open and close the throttle, if it jumps then it's bad and that's your culprit.

If you eventually get the CEL on then check the codes.
'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 sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #4 on: April 19, 2011, 08:43:04 AM »
just re-read your initial post, you say you have low voltage at the battery (missed that the first time, for some reason i thought you meant you don't have low voltage) - what is the voltage (measured with a multimeter not your dash gauge)? does it increase with the rpm? is your alternator belt tight (no slippage)?

fix that problem first, it could be your issue.
'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

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #5 on: April 19, 2011, 09:30:21 AM »
i had the alternator tested last night and its good. i just put the alternator back in the jeep 5 minutes ago and started it up it ran fine at reg. rpms. i let it rund for 5 minutes. the battery right now from my dash gauge says 9.5 volts. once it got to that low of voltage is sounded like it wanted to die. the fuel pump is electic and is probly not getting enough volts.

Offline sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #6 on: April 19, 2011, 12:04:01 PM »
i had the alternator tested last night and its good. i just put the alternator back in the jeep 5 minutes ago and started it up it ran fine at reg. rpms. i let it rund for 5 minutes. the battery right now from my dash gauge says 9.5 volts. once it got to that low of voltage is sounded like it wanted to die. the fuel pump is electic and is probly not getting enough volts.

at that voltage (if that is the real voltage) you will have issues with all the PCM (computer) as well, so that sounds like the problem. On 95YJ the alternator field is controlled by the PCM, so i hope it's the alternator or wiring related (field, ground or feed)

check the 2 50 Amp fuses in the PDC by the battery, if both those are blown there is no charge going to the battery.
'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

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #7 on: April 19, 2011, 12:23:18 PM »
ok im replacing the barrtey tommorrow after work. i checked the 2 50 amp fuses and there not blown. i hope its just because i have a battery with low voltage to solve this problem

Offline sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #8 on: April 19, 2011, 12:29:02 PM »
ok im replacing the barrtey tommorrow after work. i checked the 2 50 amp fuses and there not blown. i hope its just because i have a battery with low voltage to solve this problem

I think that even if the battery is bad you would still not have 9.5v while the engine is running
'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

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #9 on: April 19, 2011, 12:36:03 PM »
ill just a full tune up on the jeep ( new plugs, wires, fuel filter, ignition coil, and distributor cap). if tht doesnt work then new csp and tps

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #10 on: April 19, 2011, 01:00:21 PM »
battery doesnt increase when the rpms go up. and the belt is tight.

Offline sharpxmen

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Re: how come my 95 jeep is bogging down?
« Reply #11 on: April 19, 2011, 01:43:18 PM »
battery doesnt increase when the rpms go up. and the belt is tight.

sounds like a charging issue rather than the battery though.
'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

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #12 on: April 19, 2011, 01:54:40 PM »
wat could it be then other then the battery. the alternator was tested last night and it working fine

drunkencityworker

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Re: how come my 95 jeep is bogging down?
« Reply #13 on: April 22, 2011, 03:21:05 AM »
Glad to see you made it over here. I had an alt test ok but when under load it was crapola.

95yjzilla

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Re: how come my 95 jeep is bogging down?
« Reply #14 on: April 22, 2011, 07:06:00 PM »
so u think its the alternator then when its under a load. i just got done changing the plugs, wires, distribitor cap, ignition coil, tps, idle control sensor, battery, map sensor. waiting for the battery to be full charged b4 starting it.