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#1
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Would engine run great if Timing Belt 1 tooth off?
Earthworm brought up a good point, both my left side O2 and Knock sensors are posting codes, could my cam on the left be 1 tooth out? and if so, would the car run as good as every?
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#2
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Short answer.... no. And at 200+ miles it should be anyway if you haven't already. Seals too.
Another thing to keep in mind is the wiring for the left O2 and knock sensor are VERY close to eachother, they even share a clip and loom I think. So could be a wiring issue too. -edit- Actually, now that I think about it that may not be the knock sensor on that loom.... I'll have to go look sometime
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[SIGPIC][/SIGPIC] In progess: track down mystery noise <-identified, paint the new dash, get better pic Spring plans: Replace Trans - Integrate ECU with the carputer - Suspension - Go back to STI Filter - Paint? Maybe not - Next Oil change: Purolator L30165 Member #995 | My Locker | My New Locker Catch you next at: ? Auto-X ? Last edited by Speedklix; 06-03-2006 at 10:21 AM. |
#3
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There was some discussion that it would actually improve power by doing this. It was in a thread about cams, though at this point the technical details are beyond me... for now.
http://www.subaru-svx.net/forum/showthread.php?t=30498
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#4
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Thx SpeedKlix, I'm not totally convinced I have a bad O2 or Knock sensor because as you describe, they are close to each other.
And Nemesis, great read on that thread on advancing the timing, and I agree, I do believe advancement of 1 tooth can improve performance, but I'm only suspecting one side, and if I think about it I would suspect a 1 tooth slip in the opposite direction, so by counts on that thread, an 8 degree retard on my left side. So now is my delemna, since a Knock Sensor is $158CDN up here(from the dealer) 1)Can I easily test to knock sensor to ensure its toast?? 2)or should I persue the verification of the timing on the left cam? Belt was changed around either 140 or 160k miles, can't remember but I do have a log of all mainitance. Thx John H. I'm going to try and search the forum for a test proceedure, or could just do a basic resistance test and compare the 2 knock sensors?
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#5
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Many times a Subaru will be one tooth off only on one cam. Makes it very difficult to diagnose as the engine doesn't run very bad, if at all noticeable. I highly doubt that a belt being off one or thirty teeth would cause a knock sensor code - read on:
The thing to think about in this situation is how does the ECU determine that either sensor (or its respective circuitry) is bad. The ECU expects to 'see' noise from the knock sensor, whether or not there is knock present. Specfic frequencies are watched for, as they have been determined by engineers to represent actual engine knock. So... if the ECU doesn't see any response or the response never varies (in a manner of speaking), or the voltage is above/below standards (such as shorted to battery voltage) it will deduce that the sensor or its circuitry is faulty. How does it determine if an O2 sensor is bad? Several different ways - first it expects to see a voltage between 0 & 1 volt within xx amount of time after the engine has started. It also expects that voltage to begin crossing back and forth across the threshold of around .45v x times/minute within xx amount of time after the engine has started. It doesn't expect to see voltage above 1.1v. The ECU knows the engine is running because it sees an 'appropriate' signal from the crank sensor, and may also check in with other sensors to verify, such as the cam sensor, MAF, etc. p.s. When posting a code in a post it would be helpful to post the code description verbatim. I don't want to leave the post to go look it up, as I'm certain many others don't either. It would be nice if someone would find a way to make this a forum header/notice.
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ASE Certified Master Automotive Technician w/L1. ASE Certified Master Medium/Heavy Truck Technician. Certified EVT (Emergency Vehicle Technician) Last edited by Beav; 06-03-2006 at 11:13 AM. |
#6
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From the FSM, here are the values for checking the knock sensor: Found in the FSM Section 2-7, pg. 73-74
Checking Input signal for ECU: ...Turn ignition to "ON" ...Check voltage between ECU connector and body. ...Connector & Terminal/Specified voltage ...(B61) No.6—body/ 3–4V Checking Knock Sensor 2 ...Remove collector ...Disconnect connector from knock sensor 2 ...Measure resistance between knock sensor connector and body. ...Connector & Terminal/ Specified resistance ...(E19) No.1—Body/ Approx 560KΩ The first thing they want you to check is the input signal for the ECU. ...If it is OK, check the contact of the ECU connector terminal. ...If not OK, repair ECU connector and terminal. If you check the input signal for the ECU and it is not OK, then check the knock sensor 2. ...If it is not OK, replace knock sensor 2. If the knock sensor 2 is OK, repair or replace the harness connector between ECU and knock sensor 2 Maybe someone can scan these two pages and either post them or email them to you. .
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. Subaru Ambassador 1996 Polo Green LSi #216..138,100 miles...SOLD JFICX8659TH100216.....Date of Manufacture: November 16, 1995..... Fuji Heavy Industries..Ōta North Plant....Ōta City,. Gunma Prefecture, Japan In-Service Date: January 2, 1997 "The Pristine Green Polo Machine” First Polo Green on the Network First Clear front turn signals, JDM Alcyone hood emblem, rear panel, and BOXER engine cover on the Network (US) (2000) First 5000K HID factory fog lights (2007) First SVX JDM BBS wheels on a USDM SVX (2013) HID lighting (5000K) for headlight and H3 fog lights, PIAA SuperExtreme 120W high beams, rebuilt EG33 longblock, Cometic head gaskets, Phase II flexplate, AMR aluminum radiator with custom silicone hoses, 160A high-output alternator in aluminum-ceramic coated case, new design alternator wiring upgrade v.4, rare factory headlight protectors, refinished JDM BBS mesh aluminum wheels and custom, polished billet aluminum new hex center caps, LED grille mod, R1 Concepts high-carbon cryo slotted rotors, Akebono ceramic pads, Goodridge S/S braided brake lines, Smallcar Stage 1 shift kit, ThermalTech aluminum/ceramic-coated valve covers, Energy Suspension urethane front & rear swaybar bushings, Bontrager22 rear swaybar with QS Components Chromoly Teflon/Kevlar endlinks, "$15.00/5 minute" suspension mod. Hella Supertone horns, Custom stainless steel exhaust system with 2" headpipes, Magnaflow cats, AeroTurbine AR25 resonator /AWD "Bullet" muffler. R.I.P. 2010 Subaru Outback Limited 2.5 CVT...338,000 miles. Totaled by a 1,300 lb. COW March 4, 2016 2014 Hyundai Avante Limited ...178,000 miles. Actually quieter and smoother than the Outback 2007 Mazda Miata MX-5 PRHT...102,000 miles. Plenty of parts, service and windshields. 4th Registered Network member —2/21/2001 My NEW locker..I...My Email..I..Wikipedia/SVX . . Last edited by svxcess; 03-24-2013 at 11:38 PM. |
#7
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Thx Beav, you are correct:
the 1 old code and 2 new codes I'm getting are: 34: 'EGR solenoid or Circuit'. I have had the this code for over a year, and have never tried to resolve it. 28: 'Knock sensor No.2 (SVX left side)' new code 37: Oxygen sensor (No.2, left side on SVX)' new code I tried to clear these codes from the ecu and could not, so I suspect I'm either not doing it right, or they are completely dead(shorted/open or missing)
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#8
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Thx John, I'll be out there shortly to do that basic Knocker resistance test, I'll check both to see if they are the same
(SLAP) my girlfriend saw me type that. " I'm testing my car, Honey, not the neighbours"
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#9
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Good luck Chris. Hope you can resolve this before the meet this month.
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. Earl .... ... .... ><SVX(*> Subaru Ambassador [COLOR=”silver”]1992 Tri Color L[/COLOR] ~45K (06/91) #2430 1992 Dark Teal LS-L ~184K (05/91) #0739 1992 Claret LS-L ~196K (05/91) #0831 1992 Pearl LS-L ~103K (06/91) #1680 1992 Pearl LS-L ~151K (06/91) #2229 1992 Dark Teal LS ~150K (07/91) #3098 (parts car) 1992 White LS-L ~139K (08/92) #6913 1993 25th AE ~98K (02/93) #164 1993 25th AE ~58K (02/93) #176 1993 25th AE ~107K (02/93) #215 1993 25th AE ~162K (02/93) #223 1994 Laguna Blue Pearl LSi ~124K (1/94) #2408 1994 Laguna Blue Pearl LSi ~144K (10/93) #1484 1994 Laguna Blue Pearl LSi ~68K (10/93) #1525 1994 Barcelona Red LSi ~46K (02/94) #2624 1994 Pearl LSi ~41K (12/93) #1961 1995 Bordeaux Pearl LSi ~70K (02/95) #855 1996 Polo Green LSi ~95K (03/96) #872 1997 Bordeaux Pearl LSi ~55K (08/96) #097 2003 Brilliant Red LS1 Convertible ~29K (04/03) #8951 1999 Magnetic Red LS1 Coupe ~33K (04/99) #6420 My Email | Old Locker | New Locker | Picture of 15 of the 19 |
#10
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Do you realize that the EGR malfunctioning not only raises the NOx emission from your car but also increases its chances for knocking? Not that repairing the EGR will cure your knock sensor code, but it can help your mileage if the knock sensor(s) are working and detect knock that results from an inop EGR. Hope that makes as much sense to you as I intended.
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ASE Certified Master Automotive Technician w/L1. ASE Certified Master Medium/Heavy Truck Technician. Certified EVT (Emergency Vehicle Technician) |
#11
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Quote:
The main reason for this repair work is to get my car to pass our smog test: www.aircare.ca standards. I can either spend $600CDN at an approved aircare repair station, or make it pass, the test is $24. here's a quick rundown of my last results: Hydrocarbons(HC) g/km Max allowed: 0.5000, vehicle reading: 0.6922, Avg Passing reading: 0.2338, Result FAILED. Carbon Monoxide(CO) Max: 9.3200, Vehicle: 7.7610, Avg:1.9412, result: PASS Oxides of Nitrogen(NOx) Max: 1.2400, Veh: 1.9046, Avg: 0.9452, result: FAILED.
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#12
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An SVX will still run fine with one cam off a tooth.
And not throw a code. I have run my Claret with both cams advanced, and retarded a tooth, to see if it made it better or worse (at Bills insistance ) It ran best with the stock cam timing.
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#13
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Uhhh.... let me see if I can swipe - oops.. uh, borrow some charts to help diagnose engine management issues from emissions results.
BTW, cam timing may not set codes but that is just because of the various methods the ECU uses to determine malfunctions. However, the tailpipe reveals all, kinda like forensic tailpipe proctology something or other, eh? "Turn your wheels to one side and cough..." Tom, some cam timing adjustment may be good for specific reasons. Thing to remember is that if there are forty teeth on a cam sprocket (just guessing, I'm not running out to pull a cover and count), one tooth would equal 9° at the cam or 18° at the crank - huge numbers.
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ASE Certified Master Automotive Technician w/L1. ASE Certified Master Medium/Heavy Truck Technician. Certified EVT (Emergency Vehicle Technician) |
#14
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Quote of the day:forensic tailpipe proctology
Quote:
I have to just say, what an awesome quote for the day: forensic tailpipe proctology
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
#15
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Quote:
OK, I checked the right knock sensor and the left, and they are both within spec: Right = 552k ohms Left = 570k ohms So that doesn't mean that I didn't post a code 28 a wj=hile back and now the connection is ok??? Now I'm concerned that I'm reading old codes, and I've not been able to clear them. Am I chasing ghosts?
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Chris G 92 Pearlie, sold @ ~209k miles. Now owned by Tim. Current Ride, 1985 Honda Aero 80, stock 3024 klms |
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