Garrettfranks

It is a 1985 N/A 5 speed, 217xxxmiles, 80xxx on engine and transmission; salvage title (not sure why)

what i've done to the car so far: oil change, spark plugs, fuel injector cleaner, wires, radiator flush, and air intake.

the bad:
1) the after market exhaust is loud and annoying, and it rattles (cat delete, test pipe to the muffler, not sure brand of the muffler) any ideas on nice, sporty not annoyingly loud mufflers? ideas on dual exhaust?
2) the transmission if pushed into upper RPMs will violently force its self out of first gear with a loud "pop" is this normal? or just shitty rebuild?
3) random heat waves while driving? like...just... abnormally hot waves of air?
4) when key is on the 'on' position pretty apparent hissing noise from the back of the car, is this the fuel pump? or a fuel leak? or is it normal? what is it?
5) awful fumes smell after shut off, or just in general (due to cat delete?)
6) the car while driving 60 mph down a road will try to run me off, like...a ghost is pulling on the wheel against me...makes the car hard to control, is this because of the salvalge, or normal? or do i just need an alignment?

I am new to the forum and just have a few questions, as to if these are normal Z things, or if they need to be fixed. or if anyone has any successful mods that they would like to consider? (fuel injectors, chips, new fuel pump) anything to help me get my car to the car of my dreams! I'm 17 and its my first car! any things helps!

ThaPimpShrimp

Welcome to the Zdriver forums!

The transmission is definitely not supposed to do that, so not normal.

As far as random heat waves.. as in coming out of the vents.. or the car's temperature jumps.. or what?

The hissing noise sounds like it could be the fuel pump, but it shouldn't be hissing. You should probably investigate that.

The fumes could be due the the cat delete, but what do they smell like. Could be anything.

The pulling of the car to one side is definitely not a good thing and it could be from any number of causes.. accident or alignment.. I don't know why you have to ask if that's normal.

There are plenty of successful mods done to the 300zx. Probably the best of which is installing a turbo motor. However I don't suggest you spending too much money on any modifications as it sounds like your car has quite a few issues.

What I would do in your situation is take it to a good shop, and have them do a complete check-up of everything. Hopefully they'll be able to figure out most of what is wrong and then you can either decide to fix the problems yourself (with our help) or have a professional do the job.

By the way here is a link to a downloadable version of the FSM (Factory Service Manual) for your car: XenonZ31 Reference

And on the same site there is a modifications tab that has some things you can do to your car.

I suggest spending the $20 to purchase a Haynes manual for your vehicle if you plan on doing any of your own work to it. I got mine on Amazon.

Welcome again to the forums! I personally own a 280zx and haven't owned it for long so I am not very knowledgeable with your 300zx. Just helping where I can (No promises what I say is completely correct )