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Toyota Service
Toyota Service, Lexus and Toyota expert
Category: Lexus
Satisfied Customers: 4538
Experience:  30 + years of experience; Multiple Award Winning Svc Mgr; Just Answer Customer's Choice Award Winner
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Im having missfire inssues 92 ls400 when at half a tank

Customer Question

hi, im having missfire inssues 92 ls400 when at half a tank or less
JA: Sometimes things that you think will be really complicated end up being easy to fix with a Lexus. The Lexus Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so he can help you best.
Customer: ls400 bogging sluttering chocking when half a tank of gas or less
JA: Are you hoping to fix this yourself?
Customer: yes
JA: Great! What have you tried so far?
Customer: fuel pump
JA: Is there anything else important you think the Lexus Mechanic should know about your Lexus?
Customer: no
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Lexus Mechanic about your situation and then connect you two.
Submitted: 6 months ago.
Category: Lexus
Customer: replied 6 months ago.
only after 15 mins of driving it bogs down and splutters ONLY with half a tank of gas or less
Customer: replied 6 months ago.
no issues when full tank
Expert:  Toyota Service replied 6 months ago.
Hello. Welcome to Just Answer. Please allow me to assist you. Based on a misfire at 1/2 tank, my initial hypothesis on this would be a crack in the pickup tube that is connected to the fuel pump. As long as the potential crack is below the surface of the fuel, the pump will pull fuel thru the crack. When the fuel level drops, the pump will pull a little air out of the tank thru the crack, instead of fuel. The recommendation I have for you on this request would be to inspect the fuel pickup tubing very carefully, and perform a leak down test. If any evidence of a leak is found, replace the fuel pickup tube.
Customer: replied 6 months ago.
I replaced the top rubber hose because it was split, Do you think it would safe to remove the inspection cover and turn the key and make it prime and have a look inside to see if it squirts out of anywhere ? Thanks a lot
Expert:  Toyota Service replied 6 months ago.
Thanks for the reply. No, I would not remove the inspection cover and see if it squirts out. The issue is the tube pulling air. You will not see a squirt as the fuel is being drawn up the tube. The fuel pump draws the fuel & pushes it to the engine. The only way you would see a squirt would be in the line after the outlet of the pump. Also, if you get the pickup screen above the fuel, you will starve the fuel pump from fuel..This could damage it. You do not want to pull the inspection cover up with the pump running. This really sounds like a problem in the pickup tube at the level of the gasoline in the tank when it misfires.
Expert:  Toyota Service replied 6 months ago.
If you have any other questions, please feel free to reply; I will be very glad to help you further.If you do not have any questions, and are satisfied with my input on your request, thanks for choosing Just Answer. It was a pleasure to assist you today. I trust my input to your request is satisfactory to you and meets your expectations. A positive rating would be greatly appreciated for my assistance on your inquiry. Thanks in advance and thank you again for choosing Just Answer
Customer: replied 6 months ago.
thanks again for your help, it has been very helpful as i would of never of thought to check what you have suggested above, i will have a look and carry out tests and report back if unsuccessful, thankyou
Expert:  Toyota Service replied 6 months ago.
You are very welcome. Glad to help.

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