Nissan Repair Questions? Ask a Mechanic for Answers ASAP
Hey there, thanks for the question.
Did this just start happening in the cold weather? any smoke or anything when this happens?
A couple of things come to mind here.
The first being the center intake manifold gasket thats prone to leaking and causes hard starts on these engines.
The other is the possibility of something leaking into a cylinder (coolant, fuel, oil) when the car sits for awhile. This will create a hard start because of the uncombustible fluid or excessive fuel in the cylinder.
So all was going normal, then you changed trans and this started?
is this a manual or auto trans?
can you answer my other question please?
Gotcha, more commonly when this happens it's because the crank sensor was not REMOVED BEFORE swapping the transmission. When this happens the sensor is easily damaged on the edges which gives a scratchy wave pattern and causes hard starting.
Best bet at this point is to replace the crank sensor.
anything else you did that you failed to mention? before i make any other suggestions?
Ok, run a temporary ground from the bellhousing to the battery.
Let me know if it fires right up
Did you sand the mating surface where the engine and trans come together?
about the only 2 things you see relating to hard starts from transmission replacements on these cars is either the crank sensor, or grounding issues that i mentioned.
This may not be related to the transmission installation
Have you checked the actual starter itself? made sure it wasn't loose or anything? not making any weird noises when starting?
Why did you replace the starter?
At this point you may want to scope the crank sensor to see what kind of signal your getting.
There is of course other things that would cause a hard start completely unrelated to the transmission install itself.
Just seems a little peculiar that you had none of these issues prior to the replacement.
you could rule out the IAC hard starting by simply depressing the gas pedal slightly when starting.
backfiring through the intake could be from a couple different things, could be excessive fuel from a leaky injector, a bent intake valve, timing being off, or a poor/weak ignition signal.
Generally the weak ignition signal though will cause the backfire sensation at heavy acceleration as well, not just trying to start.
having 1 or more weak coils or a bad ground.
the ignition ground is on the intake manifold also.
The coils are very difficult to test accurately with a meter. The best test on these coils is to pull them and crank the engine.
I would start with an easy test to see if your bleeding off static fuel pressure.
Use a T-fitting and test idle fuel pressure, then cut the engine off and pin the soft lines and see if the pressure bleeds off. If so then an injector is leaking.
That being the case its probably only 1 of two things here.
Either the engine is flooding out, or your not getting enough air in the engine for some reason. (IAC is not operating with key to ON like it should, or air filter clogged)
Never heard back from you.
if you need further help let me know, if not be sure to leave a kind rating please.
BEST way is to either remove it and turn key ON and watch it or use a stethescope and listen to it when key turned to ON.