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Discussion Starter · #1 ·
Each time I change gears and accelerate, my car jerks back and forth and the tachometer fluctuates along with the car jerking. If I stop accelerating and maintain my speed with only a small amount of pressure on the gas pedal, the shaking stops and the car drives a lot smoother until I press on the gas pedal and/or move to the next higher gear. Searching online I found many different possible causes, but most of them seemed to be cancelled out by the fact the tachometer fluctuates up and down along with the car.
The most likely possible causes I thought might be the TPS, the MAF, a problem with the vacuum lines, a fuel delivery problem, or a timing problem.

Since then I've made sure the timing is correct, I've checked all the vacuum lines, and I mistakenly thought the TPS wasnt working and now I found out it is working fine. The fuel seems to pump through the fuel line towards the intake just fine, but could it be something with the fuel pump and the pressure of the fuel? Or could it be my MAF? I tested MAF pin resistances and all of them except for 3-6 and 1-2 tested in the right range. I'm not sure if those 2 weren't reading anything because there's a problem, or I didn't test them right?

What do you guys think? Is there any other possible causes for this to happen while driving? I'm still pretty new to all of this but so far this has been the hardest problem to figure out.. I appreciate any input you can give!
 

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I had a problem like this. It was the plug wires. Replace those, plugs and distributor rotor.


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Each time I change gears and accelerate, my car jerks back and forth and the tachometer fluctuates along with the car jerking. If I stop accelerating and maintain my speed with only a small amount of pressure on the gas pedal, the shaking stops and the car drives a lot smoother until I press on the gas pedal and/or move to the next higher gear. Searching online I found many different possible causes, but most of them seemed to be cancelled out by the fact the tachometer fluctuates up and down along with the car.
The most likely possible causes I thought might be the TPS, the MAF, a problem with the vacuum lines, a fuel delivery problem, or a timing problem.

Since then I've made sure the timing is correct, I've checked all the vacuum lines, and I mistakenly thought the TPS wasnt working and now I found out it is working fine. The fuel seems to pump through the fuel line towards the intake just fine, but could it be something with the fuel pump and the pressure of the fuel? Or could it be my MAF? I tested MAF pin resistances and all of them except for 3-6 and 1-2 tested in the right range. I'm not sure if those 2 weren't reading anything because there's a problem, or I didn't test them right?

What do you guys think? Is there any other possible causes for this to happen while driving? I'm still pretty new to all of this but so far this has been the hardest problem to figure out.. I appreciate any input you can give!
Check the fuel injectors if you feel the wires and plugs are in good condition.
 

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Discussion Starter · #4 ·
I replaced the distributor rotor and plug wires, and the plugs themselves were replaced not too long ago. When i first started working on fixing the car up i also attempted to clean out the fuel injectors and they seemed to perform perfectly fine when i first put them back in.
However, I was driving the car around with a hole in the tubing between the MAF sensor and the air intake manifold. I'm wondering how likely this problem is being caused by my MAF sensor? I checked the resistance between each of the pins and almost all readings were in the correct range. However, when reading 3-6 and 1-2, the resistance was not in the correct range. There is obviously something wrong there, so how safe is it for me to assume this could be the cause of the problem? If the MAF sensor isn't working properly, could the way i described my car driving be a possible symptom?
 
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