Gnuman Posted March 14, 2007 Share Posted March 14, 2007 Emily has over 220,000 miles on her now and the diagnostic connectors have never been used. this is evidenced by the fact that they are still taped into the wiring harness the way they came from the factory. this is an impressive record, and one I dont want to bring to an end. The problem is that Emily is throwing an intermittant CEL, only on the first run of the day, and only for a few seconds (up to about 30sec), when the temp is about halfway between stone cold and operating temp. I let it idle to Op temp one day and got an unsteady idle when the light was on, but no other symptoms are evident. No hesitation, stalling, fluxuation on any instruments, bucking, nothing at all. . . Engine is strong and steady in all other respects. My suspects are :O2 sensor (I have about 80;000 on this one), knock sensor (I have never replaced the one I have as it looked good when I last had the engine apart for the timing belt), Temp sensor (that goes to the ECU) (as this seems to be a temp related thing) Should I just bite the bullet and cut the tape (I don't wanna), or is there something that points to something I can diagnose without the codes? Quote Link to comment Share on other sites More sharing options...
tcspeer Posted March 14, 2007 Share Posted March 14, 2007 Cut the tape! A co worker of mine back in 1980 that I shared rides back and forth to work bought a new truck with air cond. In the Tx. summer heat he would not use the air cond. Use what you have to get the most help with the problems that come along. Emily has over 220,000 miles on her now and the diagnostic connectors have never been used. this is evidenced by the fact that they are still taped into the wiring harness the way they came from the factory. this is an impressive record, and one I dont want to bring to an end. The problem is that Emily is throwing an intermittant CEL, only on the first run of the day, and only for a few seconds (up to about 30sec), when the temp is about halfway between stone cold and operating temp. I let it idle to Op temp one day and got an unsteady idle when the light was on, but no other symptoms are evident. No hesitation, stalling, fluxuation on any instruments, bucking, nothing at all. . . Engine is strong and steady in all other respects. My suspects are :O2 sensor (I have about 80;000 on this one), knock sensor (I have never replaced the one I have as it looked good when I last had the engine apart for the timing belt), Temp sensor (that goes to the ECU) (as this seems to be a temp related thing) Should I just bite the bullet and cut the tape (I don't wanna), or is there something that points to something I can diagnose without the codes? Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted March 14, 2007 Share Posted March 14, 2007 Can you maybe use alligator clip or other jumper wires to make the connection without cutting the tape? Quote Link to comment Share on other sites More sharing options...
Gnuman Posted March 20, 2007 Author Share Posted March 20, 2007 Well, I think I tracked down the CEL (without cutting the tape ). I had used my #1 plug to compare to a customer's to show her that hers did not need to be replaced yet (they looked brand new. I do not like doing work that is not needed on a car). Afterwards, I looked at mine, and noticed that the center electrode was worn down a bit, and that mine needed to be replaced. I just did so and have not had a CELL since. I also noticed that the electrodes were not all worn the same ammount (two of them did not look worn at all), so I suspect that I may not be getting as good a spark on those two. Perhaps bad wires. Now for the fun part (and a reference to the Harley thread: the right fork of my Y-pipe snapped just after the head, making my car sound like a Harley. Yes, I hear a lot of cars that are louder than that on the road, but that is not the way my Subaru is supposed to sound. I called my supplier (Jason at 1stsubaruparts.com) and he said that it would take a week or so for him to get the part, and it would cost $400.I do not have that kind of cash laying about, so I'm going to a muffeler shop in the morning to see if they can weld a bit of pipe onto it. Wish me luck! (Oh, and the break is behind the heat shield, so cold backdraft is not as much of a problem. Backpressure still is, and that is part of why I want it fixed now) Perhaps this guy can help with the job. . Quote Link to comment Share on other sites More sharing options...
OB99W Posted March 20, 2007 Share Posted March 20, 2007 [...]I also noticed that the electrodes were not all worn the same ammount (two of them did not look worn at all), so I suspect that I may not be getting as good a spark on those two. Perhaps bad wires.[...]It's not due to bad wires, but reversed polarity on two plugs because of the design of the wasted spark ignition; the wear pattern depends upon which electrode the spark "originates" from. See my post #9: http://www.ultimatesubaru.org/forum/showthread.php?p=580982#post580982 Quote Link to comment Share on other sites More sharing options...
Gnuman Posted March 20, 2007 Author Share Posted March 20, 2007 Yeah, it is 1 and 4 that were worn down. So it is the wasted spark coil that is the problem. Hmmm. . . do you know of a fix? Would new wires help at all? I have no idea of the age of these wires, but it is over 80,000 miles. . . Quote Link to comment Share on other sites More sharing options...
avk Posted March 20, 2007 Share Posted March 20, 2007 That's right, electrode erosion depends on the polarity. By the way, for anyone who wants to use platinum plugs on these engines, only double-platinum will do, or you'd be wasting your money because of wasted spark. Quote Link to comment Share on other sites More sharing options...
hankosolder2 Posted March 20, 2007 Share Posted March 20, 2007 Yeah, it is 1 and 4 that were worn down. So it is the wasted spark coil that is the problem. Hmmm. . . do you know of a fix? Would new wires help at all? I have no idea of the age of these wires, but it is over 80,000 miles. . . It is not a problem- it is a function of how ANY car which uses wasted spark functions- i.e. the electrodes on the pair of plugs which are polarized one way wear faster than the other pair. (The center electrode is the positive element for two of the plugs and the negative element for the other two- as the spark jumps, a small amount of metal is transferred away from one to another...sort of like electroplating. Nathan Quote Link to comment Share on other sites More sharing options...
Gnuman Posted March 20, 2007 Author Share Posted March 20, 2007 Well, I thought for a second that the problem was not fixed this morning, as I got a CEL on the way to the exaust place (where I was getting the broken header pipe fixed) and the CEL came on hard. The pipe had been leaking for a while and when it snapped all the way through, it got real loud. Now I'm thinking that the bad exaust may have had more to do with the CEL than the plugs, by confusing the O2 WRT the mixture. I have a new Y pipe on order along with a new O2 sensor, but the pipe itself is hard to find and Jason has to get one in. Since I cannot be without a car that long, I got the broken section of pipe spliced with new as a temporary fix. CEL is cone for now. . . Quote Link to comment Share on other sites More sharing options...
OB99W Posted March 21, 2007 Share Posted March 21, 2007 Yeah, it is 1 and 4 that were worn down. So it is the wasted spark coil that is the problem. Hmmm. . . do you know of a fix? Would new wires help at all? I have no idea of the age of these wires, but it is over 80,000 miles. . .There's nothing to fix, and the difference in wear may not even affect performance very much until the gaps are significantly changed -- the center electrode of the "worn" plugs are negatively polarized, which makes them easier to fire than the "unworn" ones with reversed polarity. There's a tendency towards manufacturers using "distributed ignition" now (no, not ignition using a distributor ; I'm referring to the systems where each cylinder has a coil right at the plug). That eliminates the polarity reversal of "wasted spark", and also means that there are no high-voltage (secondary) wires; only the low-voltage (primary) wiring goes to a coil at each plug. Besides the plug polarity issue, there are other advantages to these systems -- the elimination of the secondary wires means there's much less of an "antenna" to radiate interference, for example. Also, an ignition problem at one cylinder doesn't tend to cause problems at another, making engine-running better and troubleshooting easier. Quote Link to comment Share on other sites More sharing options...
Gnuman Posted April 1, 2007 Author Share Posted April 1, 2007 OK, I've come to a decision. I'm gonna cut the tape and read whatever codes are stored in there. Thinking about it honestly, I'm never gonna let this car go until it is completely gone (way, WAY in the future) and no one will know or car it the diagnostic connectors are still taped up from the factory. On the other hand I know that they were in that condition for over 200,000 miles, and that is what really counts. If I get teh coded, I will know what the ECU is complaining about, and can fix it. If it is just the O2 sensor, I will have the benifit that I have nothing else to worry about on teh car. The new Y-pipe and O2 are on thier way even now, so that particular problem will be fixed soon. What is more worrisome to me is that the front end has a ratle when going over rough roads or bumps. I need to have a look at that, but I have other peoples cars to fix in the meantime. Quote Link to comment Share on other sites More sharing options...
Tech1967 Posted April 2, 2007 Share Posted April 2, 2007 Any exhaust leak before or close to the o2s is gonna make a code. Don't fix anything till your exhaust is done. Quote Link to comment Share on other sites More sharing options...
Gnuman Posted April 5, 2007 Author Share Posted April 5, 2007 Well, I went and cut the tape. No codes stored. Bah. Fast forward to the next day: On the way to a customer, I got the CEL again, pulled over and pulled the code: 21 - Coolant Temprature Sensor Part is on order, should arrive by Tuesday. After 223,000 miles without problems, I guess she is due a temp sender. . . Quote Link to comment Share on other sites More sharing options...
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