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Mike V.
Mike V., Hyundai Technician
Category: Hyundai
Satisfied Customers: 25203
Experience:  I have over 25 yrs. experience on all makes and models. Factory trained for Subaru and Nissan.
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When pushing the gas pedal down I have little to no

Customer Question

when pushing the gas pedal down I have little to no acceleration. have already replace the mass air flow sensor, the throttle position sensor, the timing belt, fuel pump and screen and spark plugs and wires.
What else could be causing this problem? please help
Submitted: 10 months ago.
Category: Hyundai
Expert:  Dan replied 10 months ago.

Hello my name is***** am an ASE Master Technician and I am glad to help you out with your question.

Expert:  Dan replied 10 months ago.

What codes do you have?

Customer: replied 10 months ago.
all those parts were just put on and it hasn't popped an engine light yet but it is still running eratic. I push the pedal down and can't get it to go, then when I pump the pedal it will gradually remember it is suppose to accelerate
Customer: replied 10 months ago.
it also doesn't want to shift gears, sometimes I have to shift it manually to put it in the next gear
Customer: replied 10 months ago.
what I mean is once it does start accelerating sometime it wont shift on its own
Expert:  Mike V. replied 10 months ago.

hi there,

Do you still need assistance with this?

Customer: replied 10 months ago.
Expert:  Mike V. replied 10 months ago.

Sometimes I have seen the front catalytic converter plug up on these. The one right off the exhaust manifold. A simple test is to take the O2 sensor out of the car completely, the one on the manifold BEFORE the converter and drive the car. If the converter is blocking up the exhaust the car should run better and have more power. It's going to be loud as heck when you run this test, but usually you will know right away if the power is restored. If it is, then replace the converter. Make sure to look at the one under the car as well if the first one is broken apart inside.

Please try this and let me know.


Customer: replied 10 months ago.
the local mechanic that replaced the other parts supposedly checked the o2 sensors and the converters and said they were ok but who knows. will have to check that tomorrow. Since the person also messed with the throttle adjustment, how do we make sure this is adjusted back where it needs to be?
Expert:  Mike V. replied 10 months ago.

If the throttle or TPS was out of range you should kick on a check engine light.

You can adjust it with a volt meter reading it while adjusting or a scan tool. Like I said, chances are fairly good it's in range if you don't have a code for it.

Customer: replied 10 months ago.
ok will check converters tomorrow
Expert:  Mike V. replied 10 months ago.

Sounds good, sometimes the top cat doesn't get checked properly and it can mess up the whole works.

I won't be on till after 4 eastern time tomorrow so please reply here and when I get on, I will respond.

Customer: replied 10 months ago.
we checked O2's and Cats and appears to be fine. Could it be that the throttle cable needs adjusted as when the engine was rebuilt the gas pedal was really hard to push down so they adjusted it to loosen it up, which I also think they might have also loosened the shifting cable. Could any of this be causing my problems. if so what is the correct way to adjust them back.
Expert:  Mike V. replied 10 months ago.

Ok, if you removed the O2 sensor from the exhaust as I described and the car didn't run any better I can accept that the converters are not plugged up.

As for the cable adjustment, I just don't have any info for the adjustment in 2 different sources. I do think if the cable was so far out of adjustment that you aren't able to accelerate, the throttle position sensor would be storing a code because it would be running out of range. I think though to adjust it, just take the duct off the throttle, look inside and with a helper, have them step on the gas pedal. You should see the plate inside the throttle open completely. It will just be a horizontal line going from one side of the throttle body to the other.

If not, then you can adjust the cable by loosening one nut on the throttle body and adjusting the other. This will change how it sits on the throttle and the amount of pull it has when you step on the gas.

Customer: replied 10 months ago.
ok the engine is popping misfire codes for multiple cylinders P0300 and so forth
Expert:  Mike V. replied 10 months ago.


I wish you were working on this yourself.

I say this because I think we need to take a step back and check out some other possible causes that you have listed as already checked. First one being a compression test to make sure there is good compression and that the timing belt is on correctly. Misfire codes aren't caused by poorly adjusted throttle linkage. These are either caused by electrical issues (coils) or timing or fuel injection. Even low fuel pressure.

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