My '98 Wrangler Sport, 4.0L, has developed a strangle problem. It "bucks", usually within a mile or so after starting it up. It seems like it isn't getting fuel when this happens, and it loses power. The problem only lasts for about 20 seconds, and then it runs fine. The fuel pressure was checked during these episodes, and was found to be normal (50 lbs). Plugs, cap and rotor were all inspected and were clean. Any other suggestions?

Check the all of the following
charging system, crank sensor, temp sensor, air intake temp sensor, and map sensor. Its bound to be one of those.... maybe.

Did you figure this problem out? My 98 Jeep Wrangler is doing the exact same thing. Any info would be appreciated

I took it to a Jeep dealer. They said it was an oxygen sensor. I asked why the Check Engine light never came on. The reason given was the "bucking" episodes didn't last enough to trigger it. Hope this helps.

my boss has a 97 and was having the same problem, was the oxygen sensor.

My 97 Wrangler (4.0L) has a similar problem, but it starts to buck at the TOP of the hill. Will rev without a load, but bucks badly under load. Also lasts about 20 seconds then goes away. Any thoughts??

Thanks,
JD

If you find out it's not the oxygen sensor, it could be a fuel problem. Oxygen sensors are the most common sensor to go malfunction, though.

You might want to have both 02 sensors checked. My '01 jeep started to do the same thing but only after I got up to 50 mph.

Will check the O2 sensor...both? Happens to me around 50 mph as well, after I've climbed the hill and trying to accelerate back to normal speed. Fuel is fine going up...just seems to starve at the top.

Thanks

sounds about the same as mine...almost feels like you dropped a gear after you have down shifted. Like it will die out. your check engine light will not come one because it never lasts long enough. I didn't know there were 2 of them on there till I asked to have my o2 sensor checked out. I felt like this was the problem because I just had the whole fuel system checked out along with a full tune up. $96.50 per o2 plus labor...expensive fix but well worth the life of the engine.

Dealership, of course, won't believe the O2 sensor story. When their tune-up (tho badly needed) won't fix the problem, they will install the new sensor free of labor--good answer. Upstream sensor, right? (Gotta love Haynes for not mentioning there are two.) <rant> When is Chilton coming out with a book??

Tune-up DIDN'T fix it! It was the O2 sensor...thanks to all, and don't let them tell you any different!

Tune-up DIDN'T fix it! It was the O2 sensor...thanks to all, and don't let them tell you any different!


Anyone ever hear of a throttle position censor, it's right there by your throttle body they go for around 20-25 bucks :2cents: Try 1 of them, not saying a O2 isn't anyones problem but don't depend on his advise to it strictly being, but bucking due to tps is a damn good possibility! If that don't work try replacing your fuel filter.A good part of any maintenance schedule includes changing your fuel filter every 30,000 miles. :iceslolan