Car not wanting to accelerate

jeep
cherokee

#1

I have an automatic 97 jeep Cherokee. It doesn’t want to accelerate when I push on the gas. It tries to rev up but won’t go rpms drop. Have to pull over turn it off and then turn it back on again. Sometimes it works fine, others it will do it again but will go away once it warms up. My muffler got a really bad crack on it a few weeks ago so I got that fixed. Then I changed out my spark plug wires because I had one that was absolute garbage and wouldn’t stay on. Still having problems. No check engine light comes on and the break gets hard to press whenever it won’t accelerate. Only does this when the car has been sitting awhile. Checked the trans fluid today and it was a brownish color


#2

You have lots of problems. Brownish color trans fluid is a bad thing but doesn’t likely affect the acceleration. The BRAKE (not break) get hard to press tells me you might have a large vacuum leak. You might also have a sensor or 2 failing. “Sitting awhile”?? Now how long would that be? An hour? A week? or a Month? Narrow it down a bit.

Describe in more detail what you are doing and what the car has been doing when you experience this “no acceleration” condition.


#3

One thing to look at regarding the acceleration issue is the fuel filter. I had an old ('72) Toyota that liked to clog up its fuel filter. It was easily accessible in the engine bay so it wasn’t hard to take it off and blow it out. Actually had to do that coming back to Sacramento from Lake Tahoe in the winter. Got to the top of Echo Summit, it was snowing (I was actually the last car over the pass before chain controls were instituted) when the car stopped. Being highly motivated (read cold!) it took about 2 minutes to clear from hood up to hood down. The point is, if the fuel filter gets clogged the fuel flow to the engine is reduced and acceleration goes bye-bye.


#4

It only happens when the car is acting out. Awhile is a few hours. Figured you would have gotten that since I obviously drive it regularly. So as in when the car has cooled down. I push on the gas pedal and it won’t accelerate. Engine still sounds normal and it revs, but it doesn’t want to go forward. I either have to turn the car off and back on or push the pedal all the way to the floor and it will start working. This happens shortly after I start the car. The whole time the check engine light doesn’t come on and the brake “gets hard” (since you felt the need to correct my spelling)


#5

The amount of down time was not mentioned in your original post so that comment was unnessary.

This is a separate problem from the acceleration and this is an automotive site so spelling the word brake is kind of expected.

Frankly, it sounds like you are going to need to pay about $100 to $125 for someone to look at this vehicle and recommend solutions.


#6

Besides a possible transmission problem, I would look at a defective fuel pump, clogged fuel filer, bad fuel injectors, dirty air flow sensor and even Bank 1 O2 sensor (but that I would expect to see an error code), bad crankshaft position sensor… the list can be endless


#7

I was using talk to text, asied from that spelling errors happen. This first commenter came off rude and unnecessary so I will be in return. The transmission fluid we have determined was just old and need to be replaced. There was no irregular odor and it wasn’t a normal like burnt color brown.


#8

Changed the crankshaft sensor about 6 months ago so I don’t believe that is it because my car just doesn’t turn on when that was broke. The distributor cap seems just fine and there are no leaks


#9

Although you do not have an error light, I would still attempt to pull a code immediately after it happens. You may have a “pending” code that does not illuminate the check engine light unless it happens over multiple driving cycles. The code maybe reset because the next few driving cycles are uneventful.

Just a thought.


#10

It is unclear whether your engine speed increases or decreases when the problem occurs, “tries to rev up” needs clarification.

It sound like you may have a failing upstream oxygen senor. I have seen a problem with the 4.0 liter Jeeps of that period where during the first 2 minutes of operation, before the O2 sensor is hot it sends a false signal to the PCM and results in a lean operating condition. The engine will bog down or fall flat when trying to accelerate, the engine will not rev up. After a few minutes the O2 sensor is hot and the problem will be gone.


#11

I came off as rude? Read through some of the posts here and your responses. Good Luck finding the answer to your problem.


#12

He (@Mustangman) wasn’t. And even if he was, why do you feel the need to escalate further?

I agree