Engine cranks but does not start and there is no check engine light

Hi,

If you aren't getting spark or an RPM signal, it sounds like the crankshaft position sensor has failed.

Take a look through this link:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

This is where I would start. Here are directions for replacement. The pics below correlate with the directions.

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1991 Lexus LS 400 V8-4.0L (1UZ-FE)
Procedures
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Crankshaft Position Sensor Service and Repair Procedures
PROCEDURES
PROCEDURE

Removal

1. Disconnect negative terminal cable from battery.

CAUTION: Work must be started after 90 seconds from the time the ignition switch is turned to the LOCK position and the negative (-) terminal cable is disconnected from the battery.

2. Remove engine under cover.
3. Disconnect crankshaft position sensor connector.


pic 1


4. Remove the bolt and crankshaft position sensor.

Installation


pic 2


1. Install the crankshaft position sensor with the bolt.

Torque: 6.4 N.m (56 in.lb.)

2. Connect crankshaft position sensor connector.
3. Install engine under cover.
4. Connect negative terminal cable to battery.

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Let me know if this helps or if you have other questions.

Take care and God Bless,

Joe