Need some EFI 5.0L help

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Jun 15, 2011 | 06:27 AM

Otahyoni

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From: Terre Haute, IN

Need some EFI 5.0L help

Got an 88 Mercury Grand Marquis with an EFI 302. When you let off the accelerator (coasting to a stop and such) it dies.

The codes i got:
KOEO:54- Mid temperature switch is open constantly
82- Air diverter solenoid circuit fault

KOER: 91- O2 sensor always lean

I have no idea what the two KOEO codes mean. I'm sure it needs a tuneup, but could that be all that it needs?

Help please....this is my sisters car...

Jun 15, 2011 | 06:47 AM

Lazy K

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I don`t even know what a mid-temp switch is but the first thing I would do, is pull the EGR valve vacuum pipe, plug it and see if that helps.

Jun 15, 2011 | 06:49 AM

Otahyoni

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From: Terre Haute, IN

Ill try that.

Is the air diverter solenoid like an IAC valve? Does it need cleaned or something?

Jun 15, 2011 | 06:58 AM

Lazy K

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The IAC valve has about six different names but never heard it called that, so I don`t know. I thought it was maybe the smog pump controller.

Jun 15, 2011 | 09:51 AM

timbersteel

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From: Mexico, Missouri

Air diverter solenoid could be "Stuck" open and allowing for fresh air to be continously pumped into the exhaust giving you the "O2 Always Lean". I have had several problems in the past and I ended up getting both the Thermactor Air Diverter and Air Bypass solenoids from my the Dealer.

If you do a search for those terms, TAD, TAB, Thermactor, you will find more info. I know RLA2005, Subford and myself have covered this.

Hope this helps.