Hi I have a 1990 Lexus LS 400 and having trouble with it idling rough. We have just had to replace the plugs and wires and the ACV and the problem is still there. Can anyone suggest anything?

Water or contaminants in the fuel system or possibly a bad plug wire? It can also have developed a vacuum leak at the intake manifold or an emissions system failure is possible first check your sparkplug wires that's the cheapest route! I feel like it might just be a plug wire is broken and is jumping spark or the timing belt may be stretched? Look at your mileage if around 100,000 miles then plugs and wires may be at fault?

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Check your brake wires connections because it seems that some wires are inccorectly installed and need to to inspected and refixed

idle air control valve is shot, replace it

Check the amount of vacuum on the distributor with a guage?? perhaps too high or leaking...

u will need to remove tires and support car on jack stands under the hood u will find three nuts holding the strut up u can only pull strut off once u hav removed all other bolts from below car... go to auto zone.com and look up repair manuals they will be free after u sign up which is also free

I would inspect your wires at the starter. If you live up north then corrosion is bad, clean all wires going to starter. then clean wires to back of alternator. I seriously doubt that alternator is the problem, but if you remove it you can have it tested for free at most parts stores.

Look for a vacuum leak

yes, no problem

the blower resistor is burn,its located under the glove box in the blower case

Hi again,

Any developments with your Lexus?