Hackman

Hi All,

I'm a new member to this forum. I've been reading up on previous postings about idling problems but I didn't run across the particular problem that I'm experiencing. I apologize in advance for the long post, so here goes:

I have a '91 LS400 with 118K on it. I bought it a little over a year ago with 111K. It ran great in warm weather but would run a little rough with high idle (about 1000, if I remember correctly) in the winter when cold.

I took the car in to have the brakes done. Found an honest mechanic who charged a fair price (rare combo). Since the brake work was *much* cheaper than I'd been told by another shop, I had them change the T-belt and waterpump while they were at it. I also asked them to look at the rough idle problem.

Long story short, after an air induction cleaning, new OEM plugs, and new OEM wires, it now idles all the time at anywhere from 950-1400 and runs rough (like it's running too rich). Ocassionally, it will idle nicely at 750 like it's supposed to.

The shop worked really hard at trying to figure out the problem for over two weeks. They finally checked and found a TSB about a problem with the ECU that causes fast idle speed. Recommended replacing ECU with new replacement part #.

Has anyone experienced this? Do you think this is the problem I'm experiencing?

Lextreme

I would recommend checking on the MAF, TPS and Vacuum lines. Currently my car is idling at 1600 rpm. I was told that might a vacuum line out. I am still checking. I did make some modification on oil breathing lines.

Hackman

Thanks, Lextreme. I was thinking about doing that but wasn't sure of the best way to check for leaks.

Is there a "low tech" method for checking the hoses?

hyperopt

Low tech?

Just replace all those vacuum hoses. They are cheap!

hyperopt

Lextreme,

Is you car idle high at normal operating temperature or just when it's cold? Also what year is your vehicle?