1988 Maxima

Problem: engine barely starts, dies within a few seconds, undrivable. Problem developed all of a sudden, car was working perfectly 1/2 hour earlier.

Timing belt: I changed it at 70K, it worked fine, mileage now at 120K, I didn’t check to see if it slipped a tooth.

fuel pressure normal at 30 psi (indicating pump, filter and fuel pressure regulator are all OK)

no obstruction in exhaust, I opened it in ahead of the converter

the on-board ECU computer gived a “55” signal in mode III, meaning all OK? The ECU (electronic control system computer) is supposed to exhibit 5 self-diagnosis modes, but it displays only 4 (no mode 1). Diagnosis mode selector displays no mode 1, it begins at mode 2.

Fuel is in the tank, removing the gas tank cap changes nothing (i.e., the air valve in the cap is OK)

spark looks good (3/8-inch) at high-tension lead to ground

rotor is where it should be, distributor cap looks good

I didn’t check compression, I thought no need to since was running great just before it broke.

Oil and water normal.

Suggestions please?