I have a 93 Ls400, and I have had a crank no start condition for a couple months now. I ended up taking it to a shop they said it was the injectors not pulsing. They told me that, after testing everything they said that they are 99% sure my integration relay is the culprit. I’m just wondering if that relay gose bad would it cause my injectors not to pulse, and if so, how exactly is it that is.

 

I don't see any way the integration relay could stop the engine computer from functioning properly. Sounds like the shop is thinking about a body control module issue something you see in cars 20 years newer. Integration relay is a relatively crude part it controls interior lighting headlight auto off function and a few other things not related to the engine.

 

Did they mean the circuit open relay?

https://www.clublexus.com/forums/ls-...-a-1991-a.html

For 1991, it's related to the fuel pump.. I'm not sure how much changed for 1993 without checking

1993-1994 do however have a fuel pump ecu, which is different from all other model years
https://www.clublexus.com/forums/ls-...l#post10854984

 

It sounds like an inhibiting mode to me. The ECU detects some serious problem and it triggers the circuit opening relay.

 

based off that forum, it dosent seem likely, all those component where checked and where fine.