clark

Just a follow up to my previous post discussing the idle speed control valve. I just returned from the dealer who did a diagnostic on it and they got code 31. He then proceeded to tell me that I needed a new MAF. Once they do that, they can then test it furhter to see if anything else is bad. Quoted price for a new MAF is $1004. Just in case this doesn't fix it then I assume the next step we be to go to the Idle Speed Contol Valve at a quoted price for the part at a bit over $600. This sounds like how I would trouble shoot a system because I have no diagnostic equipment. Seems like a pretty pricey way to trouble shoot. Nobody at this dealership has heard of a TSB concerning low idle or low rpm pinging.

LexLS

Something sounds funny to me. You have a repair manual right, well I would read up and try to figure this out. Just from briefly looking into this problem for you before I remember that there is a way to check if the idle speed control valve is bad or not. You may have to take yours off and test it. If it's bad then order it from www.irontoad.com and save about 20% off your dealer quoted prices.

I'm not sure what to say about this exactly, testing the ISC valve is a lot of work, but $1000+ is a lot of money to pay to figure something out. It sounds like the dealer has no better idea of what's going on than we do. I've never heard of a MAF going bad hmmm....keep up the research.

Sorry but it has been a long day, TSB=? Also, have you ever cleaned your throttle body? How many miles on your LS?

SharpLS-96

TSB= Technical Service Bulletin

LexLS

Doh I was a little slow the other day. Thanks for bringing me up to speed Sharp.

clark

I cracked open my factory repair manual and now am in the trouble shooting mode. Code 31 goes into the ECU memory which then "makes the ECU operate in the fail safe function, keeping the ignition timing and fuel injection volume constant and making ti opossible to drive the vehicle." First thing was to reset the trouble code. Simple thing to do by removing the EFI fuze for at least 10 seconds. Second thng I did was to clean the throttle body which was really nasty. Third thing I did was to adjust the throttle position sensor (TPS) clckwise increases idle rpm. (Thanks Lextreme for that tip). Idle is now at 700, but need to get it up to normal operating temp to ensure it is at 650 rpm with no load on ie; without the air conditioning on.. This is looking promising and keeping my fingers crossed.