Problems with my '94 Explorer

[TMBackstrom]

1994 Explorer XLT
4.0L V-6
Automatic
90K miles

A couple days back my Check Engine light came on and my engine started randomly bucking. The codes I'm pulling out of the computer are 57, 58, and 85. According to the book that came with the diagnostic tool, it says:

57: Neutral Pressure Switch open circuit failure, or
Circuit failed in Neutral position, or
Octane adjust service pin installed.

58: Vane Air Temperature sensor signal volt too high, or
Crank fuel service pin in use, or
Idle Tracking Switch circuit failure

85: Canister Purge solenoid-circuit failure, or
Transaxle problem-3/4 shift solenoid circuit failure, or
Electronic Control Assembly status-adaptive "lean" limit reached in fuel control program

The Check Engine light is not solid most of the time. It comes on once the engine is warmed up, and usually turns off for about 30 seconds randomly every about 5 minutes.

Yesterday at a stop light I noticed "rotten eggs" smell coming up from the exhaust.

Any ideas? Any help will be gratefully appreciated. Thanks.

 

[Redrig]

not sure maybe someone else knows more but i always thought the rotten egg smell was a catalytic converter problem.

 

[TPLYNCH]

You can get more info about the codes here. - Dead Link Removed Rotten Eggs may mean it is running rich.

 

[TMBackstrom]

Think I found the problem. I reset the memory this morning, drove her into work (CEL came on), checked memory, and came back with MAF sensor voltage low. So, I'll clean the MAF tonight and find out.

 

[TMBackstrom]

After cleaning the MAF sensor, now I'm getting 157: MAF sensor below minimum voltage. Any ideas?

 

[redthunder]

TMB, I also have a 94 POS, and getting codes 57 and 58. I replaced the IAC with one off my '88 Mustang (same piece, just electrical connector is rotated). The 58 CEL went away. Can you put your X in gear w/o pressing the brake? I have been able to do that since my 57 code came up. I was going to pick up a neutral pressure switch from NAPA tonight, they said they have it for $47.

r/t

 

[Iggy flywheel]

TM do a search on MAF. You can test the voltage haynes manual tells you how. It sounds like you need a new MAF. I would replace it with a aftermarket MAF like Pro- meter. They have a website as well......

 

[redthunder]

Update on my 94 POS. Chged the neutral pressure switch, didn't help. Still have CEL 57. Guess it must be the or Circuit failed in Neutral position, or Octane adjust service pin installed. Damn Ford. Would anybody have ANY ideas why I can put the X in gear w/o pressing the brake?

Thanks

 

[TMBackstrom]

Took some voltage readings off the MAF, and it was intermittent(9 mv most of the time. Sometimes kicked in and went to .9 v during idle). Changed her out ($120 - Ouch!) and she's working fine now. CEL is off for now. Thanks for all your help, folks.

Iggy, I don't feel like paying $450 for an aftermarket MAF.