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Jay, Certified Infiniti Technician
Category: Infiniti
Satisfied Customers: 3818
Experience:  20+years, Nissan and Infiniti experience and currently now working for a Infiniti Dealer
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I have an fx 35 2012 I bought a new motor 0 miles short

Customer Question

I have an fx 35 2012 I bought a new motor 0 miles short block I install my manifolds and plenum fuel injection ,change the cam sensors were different ect,ect,it start a the touch of the buttom,the only problem is that when yhe car is in iddle and I push the pedal full throtle it wont accelerate,but after 1000 rpm it runs like a beast what could be the problem and how I fix it,thank you
Submitted: 1 year ago.
Category: Infiniti
Expert:  Jay replied 1 year ago.

Hello my name is ***** ***** thank you for your question.

Who did the engine work? Also do you have any codes?

Customer: replied 1 year ago.
A friend of mine mechsnic no codes
Expert:  Jay replied 1 year ago.

Ok, so if I ask to check certain readings are you able to do it? Do you have a scanner to monitor readings ?

Customer: replied 1 year ago.
but it has no codes no lights on dash,someone tolk me it wasthe TPS snd that it can be calibrated with the pedal
Expert:  Jay replied 1 year ago.

We can certainly give you the steps to perform a Idle Relearn. But I would like to check a few readings.

I would like to know what the short term fuel trim readings are at idle with engine warmed up.

Customer: replied 1 year ago.
Whats that how I checked it the car has aftermarket parts,but with the other engine its runs ok,is has intake ,pulleys invidia catback ,highflow catalic,bullydog
Expert:  Jay replied 1 year ago.

With the modifications, that could be affecting the balance of air and fuel. Cold Air intakes tend to make these cars run lean.

The Short Term Fuel Trim is the measurement of air and fuel. That is the reading I need to start with.

Customer: replied 1 year ago.
Were i get it in the bullydog,the car was running perfectly with those mod and the engine I put Is exactly the same
Expert:  Jay replied 1 year ago.

I am not familiar with that type of scanner. It could be abbreviated to STFT Bank 1 and STFT Bank 2

Customer: replied 1 year ago.
Expert:  Jay replied 1 year ago.

No, Fuel Trim or Alpha, That is what I am looking for

Customer: replied 1 year ago.
Expert:  Jay replied 1 year ago.


Customer: replied 1 year ago.
Jay the car was runnning fine with all modifications bullydog check the chip inside the device and adjust the maps as necessary so thats not the problem ,so you charge me 18 dollars for nothing pls refund me
Expert:  Jay replied 1 year ago.

i was trying to help you by getting some readings. When there is no codes, the fuel trim is the first thing you would want to check. Since you can not provide me with this information, I can not help you.

I will put you in for a refund.

Thanks Jay!

Customer: replied 1 year ago.
Jay thats not the problem is has something to do with the TPS