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The text above is a follow-up to ...
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The text above is a follow-up to ...
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I have a 1990 LS400 with 100,000 miles on it. I bought it at 97,000 miles for 4K and have had no problems except having to turn the key for 2-3 seconds the first time I start it in the morning or it it sits for more than a half hour.
I changed the fuel filter 1K miles ago and it had no effect. If I go into a store and come right back, it starts immediately. In the summer it sometimes starts immediately, but not consistently.
It does not show a check engine light and performs flawlessly otherwise. The car is my only transportation while I am looking for a new job, so any major repairs are out of the question right now.
I have changed the heads of my 5.0 mustang in the yard in one afternoon, but know getting into an overhead cam engine is going to take a few days to break into at least.
Could it be injectors? I have run a lot of injector cleaner through the gas tank trying clean them out.
David in Michigan
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David,
There are a couple of things to look for on this older model.
1. The Ls400 starter goes out all the time. The starter located in the V bank so you would have to take the intake runner off to get to it. This job would require some basic tools: 10, 12, 14 mm sockets, needle nose pliers, 10, 12 and 14mm wrenches. Once you are there I would take a look at the EGR pipe this is a good time to replace it too. The EGR pipe has 2 section and lower section cracks most of the time.
2. When the vehicle doesn't start, did you see a check engine light? If you don't, I would take a close look at the fuse box. Fuse box located in the engine bay. We ran into some lose connection and it wouldn't power up the ECU.
If you can, Please provide more details. Thank you.
JP Importz
Independent Lexus & Toyota
www.jpimportz.org
Thanks for the tips. I repaired the lower egr with jbweld the first week I had it and that is one heck of a place to try to reach!
The starter performs flawlessly, but I baby it because I know how hard it is to change and quite expensive as starters go.
Each time I turn the key the engine cranks. No pause, no slow turning, no starter noise issues.
The car takes 2-3 seconds to start when it is left more than half an hour. It starts immediately if the car is still warm or if it is very hot outside. 90 degrees and above. New fuel filter had no effect. Slightly rich fuel smell at exhaust when it starts cold. No smell inside car, just outside.
Thanks in advance!
David
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David,
Inspect your EFI and main fuse. Make sure you are getting power to the ECU. If you are getting power, then it's your starter. Also it won't hurt to check for voltage on the starter side. You can access Lexus online manual through www.techinfo.lexus.com. The cot is $10 a day, it's a good tool to have when dianosting these vehicle. Good luck sir.
JP Importz
Dallas Independent Lexus and Toyota
Service, Repair and Performance
www.jpimportz.org
I checked the fuses for the Engine Control Module and the Main fuse block fuses. No rust, good continuity at each side of the fuse connection.
I am confused at your explanation of what the problem might be. The starter turns perfectly at high speed. There is no lag at all.
The only problem I have is that it takes 2-3 seconds of cranking for the engine to fire when it is cold, while it fires immediately if run in the last half hour or in very hot weather.
My 5.0 mustang has a fuel pump that runs if you put the key in accessory before cranking the starter. You can hear it humming in the tank. I presume that is to build line pressure for the injectors and an immediate start up. Does the lexus 400 pump do the same thing? The car is so well built, I cannot listen for something that is obvious on a tin can like a mustang.
Sorry to be a pain,
David
AnswerHello David,
There is a fuel pump ECU. The ECU will control certain voltage to the pump at a certain speed or RPM. For example, at idle your fuel pump ECU output 8-9V. WOT(Wide Open Throttle) fuel pump ECU output 13V +. The fuel pump located on the driver's side rear seat. Rear seats would have to come off. Feel free to contact me at the shop 214-221-3135. I would be able to give you some more pointers. Thank you.
JP Importz
Dallas Independent Lexus & Toyota
Service, Repair and Performance
www.jpimportz.org
214-221-3135
