sumolexus

I bought a 99 Rx 300 2 months ago. The dealership showed me that all the maintenance had been done.

I let it run real low on fuel but not out. Now it is cutting out sometimes and idles rough. There are no codes.

Any ideas?

Could this be a fuel filter or pump problem>

carguy07

Only at idle or when the throttle is open too?

Baetke

What is the idle speed when warmed up?
Should be between 650 and 750.
Have you inspected the IACV to make sure it is clean and operating properly?

salimshah

Lexmex (Ron) mentioned a problem related to running out of gas.

I donr recall the solution ... ECU reset?

Maybe some one remembers or if Ron sees this post, he will post.

Give it a day and then PM Lexmex.

Other thing to look at would be IACV cleanup.

Salim

sumolexus

My idle speed is correct but fluctuates.

What is the IACV?

sumolexus

It does it both. It will cut out when I am driving occasionally and the idle fluctuates.

Baetke

IACV is the Idle Air Control Valve. It is located on the bottom side of the throttle body and it controls the idle speed of the engine during warmup and under varying loads such as rear window defrost, seat heaters, A/C, etc... Dirty IACV or throttle valves could effect idle speed but it sounds like you have a problem at all rpms. This makes me suspect dirty fuel injectors.

sumolexus

It has gotten worse. It now cuts out constantly but works at highway speeds. When I floor it it seems to have normal power. I took it to a local shop not a dealership and they said that they couldn't find any codes. They thought it might be bad gas.

What do you think? How do I clean fuel injectors?

Baetke

Go into any car parts store and ask for fuel injector cleaner. They should have several to choose from. Should cost less than $5 to treat one tank of gas. Fascinating that you're not getting any trouble codes. With the symptoms you describe I would expect to get one or more misfire codes.

sumolexus

I did that and drove around for around 50 miles. Does it take longer?

Baetke

I would expect it to take a tank or two if that is the problem.

hypervish

Depends on which fuel injector cleaner you used. Which one did you get?

sumolexus

I forget which one O'reillys auto said was best then the mechanic told me to add "Heat"

hypervish

Heet is only to remove water from the fuel.

You need a fuel injector/system cleaner, I recommended Redline SL-1. It's a bit expensive but I've found it works the best.

sumolexus

Thanks

I will get some tomorrow