I got a 1990 LS400 couple weeks ago with 220k miles, the battery was dead but once jumped ran great got a new battery and for about 2-3weeks ran great except sometimes I would go to turn it on and nothing then I would move the battery or just slightly tap the terminals and it would fire up, one time had an issue with the anti lock. Anyways after about 3 weeks it started to not wanna start first I drove about 30ish minutes got home waited about an hour or so drove another 20ish minutes came back home waited 10-15 minutes go to turn on the car but got nothing but a click at first I thought it was the starter but weirdly enough I tried jumping the car with my other car and after about leaving the car to charge for about 2-5 minutes it started but had a bit of trouble. So I went out to see the prices for a new battery so I buy a new battery before I put it in the car, I decided to try and start it and boom right away started so I took it to AutoZone where they tested the battery and alternator were fine but the starter wasn’t getting all voltage it needed. After that i drove it the next day started right up then while driving every light flickered on and off for about 1-2 minutes while stopped then once I started moving again it went back to normal drove for another 30 mins then went to a family member house probably left it for an hour or two then when I went to leave started right away , went to the gas station turned off the car put gas in and then when I went to start it click and when I go to start it all the light fade away and the chumming noise dies also as if there were no battery but on the on position everything turns on normally. Waited until a family member came and I jumped my car it didn’t start right away with the jump but did the same where I let it sit for about 2 minutes and boom slowly but surely started. Next morning started then I let it sit for the rest of the day. Then I started it started on the first try no more clicks but the battery seems like it’s low but I only had it for about 2 weeks. Today I go and turn it on and it almost starts but then clicks, hook up the jumper cables and it starts the turning over process but before it actually start of ignite it dies like battery/power wise I think it’s a wiring problem and maybe a blown or low compression. Please anything will help. (I do have videos but I can’t upload through my phone I guess shows in my attachments tho) also to help when I go to start it it just cranks kinda fast then on my last attempt I heard it about to start then no power at all. Update when I had the car trying to start the positive terminal sparked and got super hot melted a piece of the jumper cables.

That would probably makes sense I will look into the problem. Thank you because I really couldn’t find much other than it being the actual starter,battery,ecu, or fuel pump, or wiring. But I will look into contacts.

I haven’t clean the battery terminals or cable eyes first I’m going to get a new battery as the one I have is a super cheap one with 585 cranking amps in the cold and living in Illinois is probably not enough but while putting the new battery will clean the terminals and cable eyes. The issue has me confused also. It’s just a game of guessing and hopefully find where it’s going bad thanks for replying will check all soon.

Guys so I fixed the battery and now it cranks forever and you hear it like bubble and burp when trying to start, then it backfired through the air intake. I’m in a rough spot with this car really don’t wanna get rid of it, I’m gonna have to put new terminals in. But anyone have ideas?