hello guys, my name is fabio and i'm from brazil, in my country i'm a mechanic.

I have two nissan maxima of my use.

Nissan maxima 30gv 1998 most complete version of it here in Brazil (I think it's similar to your infinity i30)

And I have a nissan maxima 1995 30J (basic version here in brazil)

Both have the same vq30de engine and from what I've seen everything else is the same.


I'm having problems with the nissan 30gv 1998, the car is simply weak, it doesn't seem to have the potential of a v6, it just shows its potential, when you step on the accelerator using the reduced ones, unlike the other nissan 30j I have that has the same engine , much more expert than the other.



On the nissan 30GV I did some maintenance on his engine and the following repairs were done.

Replacement of piston rings.
Crankshaft Shaft Replacement (I used the patchfinder, exactly the same in all crankshaft measurements and code.)
Rectified the heads.
Crankshaft Bearings
New Bosch fuel pump.

Anyway, I followed the manual when putting in the crankshaft sync point, it was already checked 4x and the sync points are perfect.
Equalization and cleaning of the 6 fuel injectors.

Anyway everything is correct. there is no malfunction code present on the scanner.


Anyway, I don't know what else to do.
The other nissan that I have the 30J, I also did the head rectification and gasket replacement and it's perfect, it goes well, it develops, expert to run.


Now this other one I don't know what it can be anymore, does anyone have any direction that I can investigate?

Thank you very much,

Attached are photos of the cars.

 

Do both cars have the same kind of transmission?

I mean both 5 speed with clutch pedal, or automatic.

Does the throttle open as far in the slow car as in the faster one?
I'm thinking that the throttle cable might be out of adjustment.

I would hook up a vacuum gauge to both cars. The vacuum readings should be close to the same at similar idle speeds. It's possible that you have a vacuum leak.

Perhaps your slow car has a bad maf sensor. I would trade the sensor from the fast car into the slow one, then see what happens.

I realize that English is a challenge for you. No problem. Not many of us are familiar with Brazilian Portuguese. Just describe the problems the best you can.

Welcome to the forum.

 

Yes both have de Automatic transmission

vacuum test I have not done yet, I will try this procedure

I already changed the maf sensor and the result was the same

Yes the trottle ins the same in both cars.


What I feel is different between one car and another is the following.

In the car with problems I feel its engine is heavy when accelerating it in test drive in the street

In the car that has no problems, I feel the car is very light to get out, on the accelerator, it responds quickly to the exit, but in the vehicle that has a problem, the exit is lethal, as if the trunk were full and heavy.

both cars turned on with the gear selector in
Neutral, have the same RPM, average of 800RPM


Hahaha thank for try to understend my english and realy sorryand thanks for the welcome

 

Did you compression test the '98?

Is the knock sensor new on the '98?

 

Have you considered seized or dragging brakes on the problem car?
Do all the wheel s turn relatively easy if the car is lifted off the ground?
or are one of more of the wheels hot at the center after the car has been driven for a few kilometres?