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david craig
david craig, Auto Mechanic
Category: Lexus
Satisfied Customers: 3290
Experience:  owner/mechanic at 3D Automotive
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My SC430 is missing when I first take off, I have replaced

Customer Question

My SC430 is missing when I first take off, I have replaced plugs and could pack
JA: What year is your S430?
Customer: 2003
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Spark plugs coil pack
JA: How many miles are on the car? When was the last time the plugs were changed?
Customer: 180000
JA: Anything else you think the mechanic should know?
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 Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Lexus
Expert:  david craig replied 1 year ago.

Hi Im David, I'll try and help you figure out the issue that your are having. How is the cars idle? smooth or rough?

Customer: replied 1 year ago.
I idles very smooth, I was throwing codes for cylinders 1, 3, 7 where missing. After I changed spark plugs only 3 was missing. Changed the coil on that one (bad coil) it stopped missing and every thing go smooth was idling rough before that. Started driving and no lights and things where good. Now the it is missing again.
Expert:  david craig replied 1 year ago.

I think it would be a good idea to see if all the injectors are firing. if you can access the injectors while the engine is running, listen to each of them with a stethoscope(cheap at harbor freight) make sure each are clicking at the same rate while someone gives the vehicles rpms.

Expert:  david craig replied 1 year ago.

I would also have the fuel pressure monitored during acceleration to see if it stays steady

Customer: replied 1 year ago.
Okay thanks will try that
Expert:  david craig replied 1 year ago.

let me know how it turns out.

Expert:  david craig replied 1 year ago.

hows it going with your vehicle?

Expert:  david craig replied 1 year ago.

did you monitor the fuel pressure during acceleration?

Customer: replied 1 year ago.
The problem turned out to be a combination of the coil pack and plugs plus the front two catalytic converters.