kevin phillips Posted October 18, 2008 Share Posted October 18, 2008 I have a 2007 focus from a body shop 2.3 liter that was involved in a front end wreck. The car has had a high idle since it started after the repair. During the wreck the intake and front cover were damaged and replaced. The iac valve and throttle body have also been replaced,base timing has been checked with correct tools and the crankshaft position sensor has been replaced with use of alignment tool. The only code that sets is a p0507.Fuel trims look ok and a smoke test shows no sign of a leak.It idles at about 1300 rpm most of the time but have seen it as high as 1900 at idle. Any ideas on where to go with this one? I've got 3 days in it with no change to idle.Test drive of about 50 miles hasen't changed it either. Any suggestions? Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted October 18, 2008 Share Posted October 18, 2008 All I can suggest is to take one giant step backwards and start from scratch.... When a solution defies our every effort, it is usually because we haven't given each test step it's due respect.... Have you followed PPT KE? You mention that fuel trims are "OK".... knowing what the numbers are would make me feel better (I AM a doubting Thomas). I'm sorry if I sound like a dick.... but I'm a dick and that makes me sound like one. Quote Link to comment Share on other sites More sharing options...
kevin phillips Posted October 18, 2008 Author Share Posted October 18, 2008 The short fuel trim is going between -3% and +3%. The long fuel trim is fixed at +4. I have even sent the pid data to hotline with the only reply of check to make sure iac valve is not upside down. I am about ready to burn it. I wonder about grounds up front but have cleaned any i could find.Unplugging the iac causes no change so i replaced the valve. The problem is there all the time so any pid data you might need i can get. I have reviewed the ppt and checked the egr,evap, and for vacuum leaks. I also checked the iac circuit which checked ok and even replaced the iac and the throttle body with new ford parts. The vehicle only has 5400 miles but the title is branded due to the wreck so hotline isn't very helpful with diag and my efforts have been in vain. I even rechecked the timing and pulled the intake back off and rechecked. The ppt leads to iac replacement which has been done allready with no change. The only way i have been able to change the idle is by covering up about half of the air intake and smothering it and it then idles about 750 or so. I have checked the filter and ductwork and all looks ok.I normally work on the diesels but work is slow and our gas drive guy quit last week and we have a shop full of oil changers. Quote Link to comment Share on other sites More sharing options...
G. Bedford Posted October 20, 2008 Share Posted October 20, 2008 Unplugging the iac causes no change so i replaced the valve. The only way i have been able to change the idle is by covering up about half of the air intake and smothering it and it then idles about 750 or so. It idles fast with both the IAC and the throttle cable disconnected, right? Interesting. Did you happen to inspect the PCV valve, plumbing and separator on the engine when you had the intake off? A lot of metered airflow through that system at idle and if it loses control of the metering,well, you can have problems. Nothing much more coming to mind without the vehicle in front of me. I don't have much experience with this engine other than a quick look around the WSM. Good luck. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted October 20, 2008 Share Posted October 20, 2008 I, also, do not know much about this engine but I'm willing to make a suggestion. Examine how this engine runs with the oil fill cap on and off compared with another similar engine. The crankcase vent system enters into the PCV equation in a way I cannot explain, but I know if there is a major leak such a a valve cover gasket or similar oil-type leak it will upset the idle controls on many engines. On many engines if you take the oil fill cap off while the engine is idling the idle speed will freak out due to the added air to the system. If your engine depends on a sealed crankcase that runs in a slight vacuum, and you have a (gasket, etc) leak, it will upset the idle controls. [if the quality of the fuel is so poor that it requires a spark to ignite it..... Well, there's not much more than I can say...!] /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
BrunoWilimek Posted October 20, 2008 Share Posted October 20, 2008 I looked up the pinpoint test for that code and here are the results: Possible causes: Iac circuit shorted to ground, Intake air leak after throttle body, Vacuum leaks, Damaged evap system, EGR valve leaks vacuum. Without doing the PPTest, I can't fault your diagnosis, but suspect there is unmetered air getting in from somewhere. Did you try disconnecting and plugging the evap hose? Quote Link to comment Share on other sites More sharing options...
kevin phillips Posted October 21, 2008 Author Share Posted October 21, 2008 Yes,I have plugged the evap hose,no change . The vehicle today lost the injector and coil pulse and showed no rpm signal on the ids for abot five mins then was fine. The idle is still 1200 rpm also. I rechecked the engine with smoke again today with no luck. I am wondering about a pcm issue or wiring issue ground,ect. I cannot tell any change by pulling the oil cap on this one. A new one on the lot changed slightly but nothing much. I get the feeling i'm overlooking something and tommorow i'm going to start fresh. It will be something simple when found but i'm running out of things that i know to check. I need bruce and his scope down here. I am going to check the pcv system some more tommorow. The new symptom has throwed me a curve on a allready horrible week, but I thank each of you for your ideas. I'll update tommorow if i find out anything new. Quote Link to comment Share on other sites More sharing options...
kevin phillips Posted December 18, 2008 Author Share Posted December 18, 2008 After rechecking everything again and switching out about everything from a used donor another throttle body fixed the concern.The new ford unit was bad and causing the issue.I was happy however to see it go and have again realized that new dosen't always mean good when it comes to parts.Thanks for the help and ideas. Quote Link to comment Share on other sites More sharing options...
BrunoWilimek Posted December 18, 2008 Share Posted December 18, 2008 Thanks for the update and fix. Sometimes those "new" parts that are no good can really screw up our diagnosis. What was the blurb at the bottom of one tech's postings? "Keep replacing EGR valves until you find a good one" or something like that. /forums/images/%%GRAEMLIN_URL%%/banghead.gif Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted December 18, 2008 Share Posted December 18, 2008 Thanks for the update and fix. Sometimes those "new" parts that are no good can really screw up our diagnosis. I say this in class nearly every day- "That's why you need to know HOW it works." I can't count how many times I've had arguments with customers/techs/students while diagnosing a truck: "The XXX Widget is bad." "It can't be- it's NEW!" "I didn't say it was old- I said it was F*! BAD." Most of the time the part in question is aftermarket.... Merry Christmas! /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
kevin phillips Posted December 19, 2008 Author Share Posted December 19, 2008 Usually, ford parts are good from my experience but there's always the parts that get returned and put back on the shelf.I think i've learned my lesson on this one and added a few more grey hairs in the process.I don't like to give up on anything if all possible. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted December 19, 2008 Share Posted December 19, 2008 I, also, do not know much about this engine but I'm willing to make a suggestion. Examine how this engine runs with the oil fill cap on and off compared with another similar engine. The crankcase vent system enters into the PCV equation in a way I cannot explain, but I know if there is a major leak such a a valve cover gasket or similar oil-type leak it will upset the idle controls on many engines. On many engines if you take the oil fill cap off while the engine is idling the idle speed will freak out due to the added air to the system. If your engine depends on a sealed crankcase that runs in a slight vacuum, and you have a (gasket, etc) leak, it will upset the idle controls. [if the quality of the fuel is so poor that it requires a spark to ignite it..... Well, there's not much more than I can say...!] /forums/images/%%GRAEMLIN_URL%%/grin.gif Bruce... your thinking is on the right track.... Older speed density systems didn't matter too much for "unauthorized" air... Here is our engine rpm... here is our manifold absolute pressure... here is our throttle angle... "POOF!". Mass air flow engines... well.... Is the unauthorized air upstream from the throttle plate? Is it a "vacuum leak" and located downstream from the throttle plate... Is the MAF wearing a "fur coat"? There is a TSB for vacuum leak diag using the scan tool.... if, for some reason, the diesel engine ever begins to sport an "active" throttle plate, this may be pertinent. MAF system or speed density sytem... the IAC will rarely be at "rest".... When we are driving, the IAC will move to full open to provide "dashpot" action should the throttle be closed abruptly. There are ever so many things that are, in reality, useless to us.... but they can be so fascinating.... Quote Link to comment Share on other sites More sharing options...
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