 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Ford / Ford Explorer / February 2006'91 Explorer fuel trim
Yet another post in the ongoing saga of my '91... The truck gets lousy mileage (12 mixed instead of 16) and shows other indications of running too rich. Codes are mostly EGO not switching, left bank lean but occasionally left bank rich. I'm convinced that something, somewhere is fooling the computer into thinking that it's running lean and the computer is forcing it to run rich as a result. Computer, EGO sensors, et cetera checked and / or replaced. The odd thing that the mechanic noticed last time was that his scanner (or whatever you call the thing that talks to the computer) showed that the "Fuel Trim" was at 0 and not moving. He said that this should move up and down (positive and negative) in response to the voltage from the EGO sensor, but for some reason was not. What could cause the fuel trim to act this way? What can be done about it?  SignatureJohn D. Goulden leaking upper/lower intake gasket ? any coolant in oil or high oil consumption ?? > Yet another post in the ongoing saga of my '91... > [quoted text clipped - 10 lines] > > What could cause the fuel trim to act this way? What can be done about it? > leaking upper/lower intake gasket ? > any coolant in oil or high oil consumption ?? Engine is only 10K into a rebuild, so hopefully the gaskets are fine. Coolant and oil levels are steady; oil looked fine when they last changed it. SignatureJohn D. Goulden Did you replace the FPR(Fuel Pressure Regulator)? Computer told me basically nothing but over at the Explorer Forums they said replace the FPR and O2 Sensor and all would probably be well. They were right except I cleaned the O2 sensor instead of replacing it. > Did you replace the FPR(Fuel Pressure Regulator)? Computer told me > basically nothing but over at the Explorer Forums they said replace the > FPR and O2 Sensor and all would probably be well. They were right > except I cleaned the O2 sensor instead of replacing it. Since my earlier symptoms were indeed consistent with a bad fuel pressure regulator (at least according to Jeff Singleton's Ford Explorer Maintainence pages, archived at http://www.explorerforum.com/Singleton/exp.html) I had the shop check it when it was in time before last. They said the fuel pressure looked OK, so the FPR wasn't replaced. If someone can convince me that a bad FPR would cause the computer to show that the fuel trim wasn't moving, I'll go ahead and have it replaced. Perhaps I ought to do it anyway, but (a) as I said I'm not convinced that this could affect the fuel trim and (b) I'm to the point where I'm throwing good money after bad at this problem. Getting the mileage back up to 16 from 12 will saves me about $500 over the next year, but I've already spent nearly that already on this problem, to no effect. The really sad part is during the first few months after the rebuild last summer I was getting the best mileage ever on that truck - close to 20 mpg on some tanks. I really would like to know what happened to cause it to fall like it did. SignatureJohn D. Goulden
|
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.