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2.5 97 Wrangler small backfire sputtering loss of power

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6.9K views 8 replies 4 participants last post by  Tbayfinn  
#1 ·
2.5 liter 1997 Jeep Wrangler

So iv searched the web for sometime on this problem. First, it starts and idles fine every time. Engine can either be cold or hot. Happens in first gear at initial take off, or even at the point when the clutch is fully release and load is beginning to occur on the engine. Occasionally happens when shifting into second and load is beginning again. What happens is when I give it gas, easy or hard, the RPMs drop, one small pop out the exhaust (no pop in intake), and idles slightly lower than normal. I have to release the gas peddle in order for it to stop sputtering and than give the gas a tap to return to normal idle speed.

Things that have been replaced this week:
Idle air control sensor
MAP sensor
Intake Air Temperature sensor
Throttle Body Position sensor

Any Ideas?
 
#6 ·
If after the ignition system is found to be in good shape, you might try unplugging the upstream o2 sensor and drive it. If that makes the problem disappear, then just change it out for a new one. It worked on mine with a very similar set of symptoms and I never had a check engine light come on indicating a problem with the sensor.......until I ran it unplugged, which will set off the light
 
#7 ·
Alright, so last night i changed plugs, wires, distributor cap, distributor rotor. problem still persisted. today i changed the fuel pump and man the fuel strainers were horrible black and brown. changed those too. As of right now, its running perfect. haven't felt a sputtering yet. Not keeping my hopes up as most of the time I'm let down. If problem comes back, i will change the upstream O2 sensor next. I hate when threads end with no solution so i will post again at the end of the day tomorrow. thanks for the advice guys