help with EGR vacuum control

This car has worked perfectly up until this problem. One day I cranked her and we got about 1 mile from home and she just did not want to go. I did not want to walk so I continued to give her the gas. After about 4 miles all was ok except that I pulled over because of smoke. Many people stopped because they thought car was on fire( It was that bad). This was many months ago and it still does the same thing. It must comepletly cool down after doing it in morning before it will do again in evening. Also there have probably been 5 times out of 200 that the problem did not occur. Thanks to all for help!!

[oab_au]

Originally posted by possumfat9
This car has worked perfectly up until this problem. One day I cranked her and we got about 1 mile from home and she just did not want to go. I did not want to walk so I continued to give her the gas. After about 4 miles all was ok except that I pulled over because of smoke. Many people stopped because they thought car was on fire( It was that bad). This was many months ago and it still does the same thing. It must comepletly cool down after doing it in morning before it will do again in evening. Also there have probably been 5 times out of 200 that the problem did not occur. Thanks to all for help!!

Hi Mate, This is what I would do if you were a coustomer of mine. I'd keep the car over night, hook it up to an analyser check, Spark advance, and fuel injector pulse duration for both banks. Then I would just sit there as it was started watching for the clues. This would be in the form of the spark retarding back more than 10 degs from the normal, or the injector pulse length shortening.

The injection pulse should start high, coming down as it warms up,( don't know for sure, but it may use a double pulse,at first to supply the extra fuel ). If it is going lean you will see the pulse length shorten. I would check using a twin trace scope, comparing say the middle injector on each side, at the same time. The ECU can operate them independently, and as the ECU gives a code for one o2 sensor, it may be confined to one side.

I reckon this has gone past the guessing game, and needs some expert looking into. I am sure that if this was done, it would show either the spark or fuel change to cause the trouble. If not it would have be an act of God.

Harvey.

I have now replaced many things including knock sensors but still have the problem. Agin here is cut and paste from subaru tech manual.
Legacy
Key On ................ Red & Black/Red ............ 10-13 Volts
Engine On ............. Red & Black/Red ............ 13-14 Volts
Key On ............... Black & Black/Red ............ 0-0.3 Volt
Engine On ............ Black & Black/Red ......... 0.8-1.2 Volts
Key On .............. White & Black/Red ............. Zero Volts
Engine On ........... White & Black/Red ............. Zero Volts
Loyale
Key Off ............... Black & Ground ............... 0-10 Ohms
Key On ................. Red & Ground ............ 10 Volts Min.
Key On ................. White & Black .......... (1) .1-.5 Volt
SVX
Key On ................... Black/Red ............... 10-13 Volts
Key On ..................... White ................. 0-0.3 Volts
Key On ..................... Black .................. Zero Volts
Engine On ................ Black/Red ............... 13-14 Volts
Engine On .................. White ............... 0.8-1.2 Volts
Engine On .................. Black .................. Zero Volts
notice that svx does not show where to test to. ground- etc. In earlier post it was stated to test to ground. This would be impossible because if you look at wiring diagram blk/red wire is grounded, therefore therefore 10-14 volts will never sow up on this lead. Still trying to solve this problem. Thanks again

[oab_au]

Originally posted by possumfat9
I have now replaced many things including knock sensors but still have the problem. Agin here is cut and paste from subaru tech manual.
Legacy
Key On ................ Red & Black/Red ............ 10-13 Volts
Engine On ............. Red & Black/Red ............ 13-14 Volts
Key On ............... Black & Black/Red ............ 0-0.3 Volt
Engine On ............ Black & Black/Red ......... 0.8-1.2 Volts
Key On .............. White & Black/Red ............. Zero Volts
Engine On ........... White & Black/Red ............. Zero Volts
Loyale
Key Off ............... Black & Ground ............... 0-10 Ohms
Key On ................. Red & Ground ............ 10 Volts Min.
Key On ................. White & Black .......... (1) .1-.5 Volt
SVX
Key On ................... Black/Red ............... 10-13 Volts
Key On ..................... White ................. 0-0.3 Volts
Key On ..................... Black .................. Zero Volts
Engine On ................ Black/Red ............... 13-14 Volts
Engine On .................. White ............... 0.8-1.2 Volts
Engine On .................. Black .................. Zero Volts
notice that svx does not show where to test to. ground- etc. In earlier post it was stated to test to ground. This would be impossible because if you look at wiring diagram blk/red wire is grounded, therefore therefore 10-14 volts will never sow up on this lead. Still trying to solve this problem. Thanks again

Hi mate, it does look like the book colour code is wrong. In my book it says to test to the body of the MAF sensor itself, it is the ground point.
Key on eng. off, red to body=10 to 13V, White to body 0-0.3V
Engine on, red to body= 13-1, White to body 0.8-1.2V

The white wire is the signal, the red the supply. If something is going on here, either the red voltage will go down below supply, or the white signal voltage will drop towards 0V, when the problem occures.

All the best in your hunt.

Harvey.

[rbalach]

Hi possumfat9,

What i'm about to say might be COMPLETELY unrelated. I have an older motorcycle that was doing something similar (backfiring into the intake). I had to remove the carbs and clean them out, that fixed the problem a little bit but not completely.Then i bought something called "Seafoam", it is some kind of carb/injector cleaner, I poured that in a tank of gas and it seemed to fix the bike right up.
The point is, my carbs were no good, so the bike was running lean, the lean running was causing it to back fire into the intake. Do you think the injectors could be acting up when its cold and behave ok once it has warmed up. Try this thing called Seafoam, it just might help. I found the stuff at Advanced Auto Parts here in Austin Texas.

I just talked to a friend of mine and he suggested:
While the car is runninig lousy, start disconnected the power to the injectors one at a time (unplug, notice difference in engine performance, plug it back in, move on to next injector). IF there is one that doesn't make a difference in the way the engine is running, that could be your bad injector.

Hope something out of all this helps.

RB

[RisingPhoenix]

Originally Posted by possumfat9

Well, I appreciate all of the responses that I have received. I have now replaced all of the egr components and car still does the same. There is no subaru dealer anywhere near me. Last week I convinced a local service center to rent the software require from Snap-on to test my car.(strange that Subaru is not standard software with these analizers.) The problem has been determined but no reason found. It appears that after starting car that computer starts to retard timing. There should be certain default points in sytem but if so they are wrong. Anyway, computer retards timing until I am suffering from pre-detonation. (explains why dip stick blows out and crancase gets preasure-rised and oil goes everywhere.) I have studied the operation theary of this system and determined that Knock sensors were bad. I replaced them and new intake gaskets and it did no good. Now after talking to tech, we concluded must be computer malfunction.( high price article) I have noticed people here talking about resistor on Ebay. In theory it should make timing advance a small bit because of computer thinking air is colder than it actually is. I thought this would help test computer, so I bought one for 9 bucks. Instructions say to put resistor in place of Air temp sensor. I have studied eletric diagram and parts locator disc and see no such sensor. I e-mailed seller and he states that I should jump IAT Sensor in the mass air flow sensor. I have looked and still see no such thing. If anyone could please help me find the air temp sensor so that i can at least try this. If you notice I have posted only a few times and it always concerned this problem, as it has been going on about a year now. Again to explain problem.

I crank car and all is fine(runs good) As soon as temp hand starts to move car starts cutting out bad and back firing thru intake. If I press gas as to go faster than about 5 mph it skips and blows oil everywhere and exaust gets real hot and oil starts getting on it. smokes as if car is on fire. After engine reaches operating temp all is well again, its as if it never happened.(after oil is burnt off exaust that is) If I crank car and let it idle for 10 minutes it never has this problem. I love my SVX and have spent much time on it and really need to get this under control. Thanks to all.

This is odd. How many car owners has this SVX had? What's the maintenance record like? Try replacing your coolant temperature sensor with OEM (avoid aftermarket)
The problems you describe may be anything, though if it's a 1994 or older I'd suspect the Crank Angle Sensor and the Cam Sensor that sit underneath the alternator.
Clean these off with Seafoam or electronic cleaner such as Mass Air Flow cleaner then reinstall.
May solve your problem..