Michael

It cranks but unable to start the engine. There is no spark coming to any of cylinder. I checked two front ones (both right and left) and no spark. This may be an indication that the ignition coils are OK. Or may be both are failing but it is unlikely that both coils are out at the same time. Any idea what the problem might be? I have '93 with about 150K miles. Any help would be appreciated.

oldskewel

iTrader: (1)

Just confirming - you confirmed no spark on cylinders 1 and 2 (front left and front right), and yes, those are powered by different coils. So I agree, very unlikely to be a coil or distributor problem. So you should consider things upstream of those that would kill both left and right coils.

RA40

iTrader: (6)

As reading material:
https://www.clublexus.com/forums/ls-...capacitor.html

This is also interesting:

dicer

Most likely is the crank position sensor, possible a cam sensor, they are the single source for ignition and since both are affected it is not coil, or igniters. Also need to make sure actual power coming from ignition switch. And the ECU is a suspect before other discreet ignition components.

PureDrifter

iTrader: (10)

go through the entire ignition system, from coils and ignitors, rotor to plug, then check the CPS.

Michael

Thanks all for trying to help but the problem was at the fuse box, it was a relay not making a contact.

I also noticed that the there is not fuel coming to the spark plug. When there are no spark and no fuel, it had to be something simple.

I checked the repair manual and the black relay in the fuse area next to the battery is the Engine Main Rely. I pulled it out and put that back in and the car started right up.

I have noticed when the key is turned to on position, there were no fuel pump running and also found when the plugs were pulled, it was dry and no fuel smell to found fuel is not coming along with no spark.

I am sure this will happen to someone at some point.

dicer

Slight corrosion on connectors just the movement of remove and install helped it make contact. Good job finding it.
Its like the pesky door lock switches not working.

Michael

This is not related to the engine starting problem but what sort of lock switch problem are you referring to? I have a problem with current loss at the fuse box under the dash that I am unable to use the lock/power_seat/trunk_release/fuel_lid_release function as I have removed a relay which is responsible for the functions mentioned. I have a short somewhere among the listed functions above but not sure how to identify. I am not sure if the pesky door lock issue is related to my problem.... You can PM me if you can as this is not related to the starting problem.