I have a 91 SE-R Sentra..SR20DE. It is being a TOTAL PAIN.

The car has been broken for almost three months now it seems, my girlfriend drove it home from work and it was fine, we got in it to get dinner, it wouldn't start.

So I immediately started trouble shooting the obvious. It gets fuel and spark. I changed the plugs, rotor, cap and some other things. Still no luck, then fried the starter trying.

I recently put on a new starter, MAF, and TPS. It started after charging the battery, ran fine for the few minutes it ran, then I turned it off to clean up and tighten a few things, tried to start again, FAIL. I looked at the ECU and found a ground coming out entirely undone, fixed that up and went home for the night.

Today I charged the battery again, it started, turned it off, still no luck starting it back up a little while later.

Went and bought a new battery as the old one was declared dead.

Still won't start.

What else can I check? IT HAS to run ASAP. I am so lost on what to check! I know it has spark, it's getting fuel, the pressure is unknown but it's flowing, I've cleaned a lot of sensors, NO CEL, no codes, WTF?!!!

It may be getting too much fuel and flooding the cylinders. This would be a injector o-ring culprit, do you smell a strong odor of gas? What do the plugs look like when you take them out after it has ran?

Yep. I'd change the O-rings, then check the pressure regulator. Make sure to lube the new O-rings with engine oil when you put the injectors back in.