Hey all,
This is my first post so let me give you some background. I'm building a 77 toyota hilux into a crawler with a 1uz out of a 1992 ls400 as the power plant. This is a jdm no egr motor with about 50,000 miles and basically bone stock condition. The computer's capacitors have all been replaced and I've done all the wiring myself on the project. My issue is a gradual one. I first tested the motor several weeks ago and to my surprise it started right up and revved to any rpm with no problems . I was excited and proceeded to loom up all wires and clean up my engine bay. It was charging and pulling no codes as well. I tiddy everything up and the next time I go to start it it starts but quickly bogs the idle down. It revs but almost dies coming down. Spark is good, I checked both banks, both are firing. Pulls code 24. Air temp. Next day I test the MAF and all tests are within spec (power to sensor and sensor resistance). Then it won't even start. It fires once but won't catch. I hold the throttle at 10 degrees open and it fires right up but dies if I let go or throttle too hard so I think it's the TPS sensor on the fritz. I get a new one and now it does NOTHING . It occasionally fires once but that is it. It has spark and fuel (sprayed fuel down intake and it fires). Pulls no codes again once it was restarted. I am very confused, is it worth sending in the computer for analysis? It's just weird to me that it ran fantastic when I first started it and then slowly loses the ability to run. Any hints or starting points would be much appreciated

 

A 92 with 50k on it. Sweet. One thing though is that timing belt is twenty years old. They are susceptible to age. The timing may have jumped couple teeth. I wouldn't worry to much about about the electronics. I think if it was that it would not have started the first time.

 

Are you using a US spec harness on it? If you maintained the diagnostic port, this test will check the ripple on the ECU:

https://www.clublexus.com/forums/ls4...-by-yamae.html

 

As far as your comment cobalt91, the timing belt is brand new as is the cap and rotors plugs and wires and ignition coils. Both ignitors function well and I have traced the spark back to them to ensure they both work. Also I don't think it is a timing problem because on my last attempt to start it it would fire but not catch. Then when I held the throttle partially open it ran which means the timing is fine. Right? RA40 , I am using the stock jdm harness that came with the engine and the diagnostic port is intact. I will perform this test soon and let you know the results. Thanks for the info!

 

Your statements reminds me of an inhibiting mode.

 

Definitely not inhibit mode. The fuel pump is wired completely separate from the engine.