97 Maxima Hard Start

Clean your throttle body, make sure your oil filter has a good anti-drainback valve, or switch back to a Nissan OEM filter. The throttle body cleaning will do wonders for cold starts and low rpm driveability. Make sure to buy cleaner that is safe for feul injected engines. DO NOT use carbeurator cleaner.

I question your mechanics ability if he said he did the wires and O2 sensors. The wires aren't necessary to change at all and the O2 is way way overkill.

CD

What wires? The Max doesn't have any. How would an oil filter drain back valve effect starting? Maybe a little clatter, but not starting. I would check the fuel rail pressure and see if any codes are set.

Exactly, the NDIS system in the Maxima has wires. The energy has to get to the spark plug somehow:)And you never need to change those wires. So we agree on that part kinda sorta. If the anti-drainback valve is defective, all the oil will drain back into the pan. The car will attempt to start in absolute dry conditions. Those conditions would make starting more difficult, which he is experiencing.

CD

thanks for the info!!

checked your suggestions with my mechanic...he did clean the throttle body, fuel pressure codes, new fuel pump, and I do have a Nissan filter on it. Any other suggestions...thanks

My 95 maxima was hard starting if the engine was cold. Would always start easily if the engine was warm. Too make a long story short it turned out to be the ignition switch wiring harness. There is (for my car) an extra contact between run & 'starter engagement' that sends an 'early start' signal to the computer.

Guess the signal is used to adjust amount of fuel during cold start situations. Part was ordered from autozone & the new part arrived in a Nissan box. Took about one hour to install. Cost was around $30.

My 95 maxima was hard starting if the engine was cold. Would always start easily if the engine was warm. Too make a long story short it turned out to be the ignition switch wiring harness. There is (for my car) an extra contact between run & 'starter engagement' that sends an 'early start' signal to the computer.

Guess the signal is used to adjust amount of fuel during cold start situations. Part was ordered from autozone & the new part arrived in a Nissan box. Took about one hour to install. Cost was around $30.

Try an EFI engine temp sensor.

If he replaced the fuel pump and starter trying to fix this, he's an idiot.