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A studering problem

89minijeep

NAXJA Forum User
Location
Florida
now i dont know what it is, maybe my lead foot but when i go to step on the gas after cruisings at around 2000-2500 RPM it gargles for gas even with a full tank, looses about 300 rpm of power then jumps to 3100 rpm , it all so happens between 1st and 2nd when accelerating hard. I read somewhere that it was the TPS so when swaped motors i also bought a new TPS. im at 300 miles on the new motor and even sometimes just bruising around town between 1500 - 2200 RPM i can feel a little studder. Any suggestions? its An 89 with an auto tranny. thanks
 
I would suspect the tranny, namely the torque convertor. A torque convertor that is acting up can cause these symptoms. Remember that you have a locking torque convertor and when you go WOT it may unlock, causing a temporary shudder and fluxuation in rpms.
 
I had the same problem, seemed to be a combination of things. TPS was out of adjustment (possibly bad/replaced) and the torque converter was locking and unlocking, multiple times, at around 2000 with a moderate throttle, during acceleration (hard throttle unlocks it anyway). At the same time, the motor was a little starved for gas, because my O2 sensor was going, also made it hunt at idle.
My EGR was opening a little early (low vacume), it all added up, to a crappy running motor.
Setting the TPS, some higher/lower than FSM recommendations (ended up close to 84% on the tranny side of the TPS and 13% on the ECU side of the TPS) seemed to add some zip and smoothed the idle noticably.
Re indexed my distributor, six months ago (after a normal tune up), was a noticeable/bad miss, at mid to high RPM. Distributor was a little loose (play). Timing chain is also a little loose (feels like it´s close to the outside tolerance).
For a work in progress, it runs pretty darn good now.
 
I have this same problem... not sure what is causing it but it was pretty bad after I got the jeep, then went away for a few months and now just recently is back. What you describe is exactly the problem I have... it almost feels like the motor is going to die for a second, like you're stepping on the gas but nothing's happening, then it just goes. Happens to me on the highway more frequently going from 3rd to 4th, and sometimes when I'm just cruising and trying to keep an even throttle.

BTW, mine is a 5 speed, so I think this problem is not to do with the torque converter, if what you're describing is the same thing... it's definately an issue with the motor, not the tranny or the torque converter, though similar things might be close when dealing with an auto.
 
I changed my filter around Christmas, dumped it into a clean jar and took a look, some serious junk came out of the in side. Did a fuel pressure test.
Mine felt like it was about half dead above 2200-2500 RPM´s or so and had a hesitation when accelerating from mid to higher RPM´s, also the idle fluctuated (up and down in cycles, hunted). Most of these symptoms, went away with a O2 sensor change, then dialing in the TPS for driveabilty became much easier.
I also swapped in a spare MAP, just for a test, wasn´t my problem, but a possiblity.
Things are coming together.
Many of the sensors are inter-related, when more than one is funcky, not to mention corroded/dirty/oily connectors, things get interesting.
 
Alright neat, where whould i go to get the distibutor indexed? i swaped tps's with the new motor, so i know its got to be within the computer, i think ill install a new o2 sensor and check my egr. ill keep yall posted, if we work together we could probobly save a good amount of money. Thanks
 
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