Time to play "Which sensor's broken?"!!!

[oab_au]

Originally Posted by SVX10

Well, tube 2 from the diagram above was most definitely cleanly severed and not going into the EGR valve. the exhaust gas was just venting into the engine bay, and the opening on the EGR valve was probably 3/4 open to the atmosphere (there was maybe 1/4 overlap between the tube and the hole still.

So, I've got the JB weld curing right now so I can at least re-install it and see if that fixes my issues. Here's to hoping...

Well that will do it.
When the engine was hot enough, the EGR would open to take exhaust gas in, but instead it was taking air in that was not accounted for by the MAF, so it ran lean, causing the PUFF, PUFF, PUFF.
When you unplugged the Temps sensor, the ECU thought the engine was cold and turned it off.

Congratulations.
Harvey.

[SVX10]

The JB weld hadn't cured yet when I got back home yesterday, so no test yet, but my expectations are very high. The EGR valve fits the symptoms perfectly, so I'm really expecting the issue to be resolved. I'll let y'all know how it goes when I get home tonight and re-install it.

[yt]

problem here is, The EGR never opens at idle, at least it should not. The fact that the car was dying at idle means you either have a hung valve, or this is not the root cause of the issues at hand. Try making a small block off plate to sandwich between the manifold and pipe 3 in the drawing. This will effectively rule out the EGR as being an issue

Tom

[SVX10]

Or we can rule out the EGR by the fact that re-connecting tube #2 didn't fix the problem.

Not sure where to go next. I suppose it could still be the EGR...maybe the valve itself...

ugh

[SVX10]

So, tonight when I first started it up after re-installing the EGR pipe, it was running on only 3 cylinders...the entire passenger's side was dead. I played with connectors to the coils and injectors for a while. Injectors were working as I smelt unburned fuel. Slowly the engine smoothed out and all but the passenger side center cylinder were working. I played with the connector for that coil and it smoothed out. So, I thought I just had some loose connections after removing the coils this week.

However, now I'm wondering if I'm dealing with this
http://www.subaru-svx.net/forum/show...ht=coil&page=2
I did do the cam seals before all this happened, after all...

I'm also wondering if I drive it around for a while with injector cleaner if it will improve. It sat for so long that I wonder also if it's just all gunked up. Fuel filter is new, though.

[SoCal LS-L]

Have you done a hard reset of the ECU? I would disconnect the battery and leave it disconnected for at least an hour, then see what happens. Can't hurt to try!

If not, then the next step may be borrowing a select monitor, or measuring voltage signals AT the ECU itself..... I still suspect the presence of rodent damage since this happened after months of sitting.

EDIT: <Tires skidding to a stop> I just read your last one posted while I was replying, if playing with the coil connectors helped the situation, then the leads may have worn or corroded. Unplug and inspect and make sure the female ends have sufficient deflection to make good contact with the male end when you plug them in.

[SVX10]

Tom,
I know you already posted this, but now it's seeming more and more probable.

http://www.subaru-svx.net/forum/showthread.php?t=45408

[SVX10]

Originally Posted by SoCal LS-L

Have you done a hard reset of the ECU? I would disconnect the battery and leave it disconnected for at least an hour, then see what happens. Can't hurt to try!

If not, then the next step may be borrowing a select monitor, or measuring voltage signals AT the ECU itself..... I still suspect the presence of rodent damage since this happened after months of sitting.

EDIT: <Tires skidding to a stop> I just read your last one posted while I was replying, if playing with the coil connectors helped the situation, then the leads may have worn or corroded. Unplug and inspect and make sure the female ends have sufficient deflection to make good contact with the male end when you plug them in.

It starts fine most of the time, but this 1st start after having the battery out overnight and after re-connecting the EGR tube it idled on 3 cylinders, with the passenger side not working properly. Ever since that 1st start, though, I've had no issues with starting.

I don't think rodent damage is a concern. I can't say I've ever even seen a rodent here in Tempe, AZ. Black widows...yes ...geckos...yes ...rodents...never.

[SoCal LS-L]

Originally Posted by SVX10

I don't think rodent damage is a concern. I can't say I've ever even seen a rodent here in Tempe, AZ. Black widows...yes ...geckos...yes ...rodents...never.

Theres probably one licking himself in your blower unit right now.... Kangaroo rats are prolific in the lower desert, but they dont exactly dance around waving their arms for attention. A simple mouse trap w/ peanut butter bait set by an exterior wall will deliver the verdict.

At any rate, since you did replace that sides cam sensor, id just double check the wiring to it, the coil connections as mentioned, then finally yank the timing stuff and see if you inherited the cam gear tab problem.

[SVX10]

What should the cold and warm resistance readings be for the CTS?

Can anybody explain the mechanism behind how the cam sprocket being loose/out of alignment with the cam would allow it to run just fine while warming up, then suddenly die at the same point in the warm-up cycle every time?

How about why occasionally it only starts w/3 cylinders, then 5 minutes later is running on all 6?

How about revving fine and holding an on-throttle RPM for up to a minute before instantaneously cutting everything and stalling?

[Trevor]

Originally Posted by SVX10

What should the cold and warm resistance readings be for the CTS?

Can anybody explain the mechanism behind how the cam sprocket being loose/out of alignment with the cam would allow it to run just fine while warming up, then suddenly die at the same point in the warm-up cycle every time?

How about why occasionally it only starts w/3 cylinders, then 5 minutes later is running on all 6?

How about revving fine and holding an on-throttle RPM for up to a minute before instantaneously cutting everything and stalling?

As you have concluded the fault can not be logically associated with valve timing.

Tom has recorded an experience whereby an intermittent fault in the LT coil circuit wiring, has affected one bank of cylinders. As I recall it this was a difficult fault to locate. If he does not notice this post, I suggest you send him a PM.

[yt]

The fact that it is isolated to one bank means one of two things

1. The power source to the RH bank coils is intermittent

2. The cam is out of it.

So, check the power feed to all the coils on the RH side of the engine and confirm 12v at all of them when it is running rough.

If the voltage is good all the time.... Then you will need to pull the gear like I had mentioned earlier and confirm the wear issue on the gear & keyway

Tom

[yt]

those coils look like **** IMHO. They really should be replaced as a matter of course. I think once they are replaced we need to re-assess

Tom

[yt]

Originally Posted by Trevor

As you have concluded the fault can not be logically associated with valve timing.

Tom has recorded an experience whereby an intermittent fault in the LT coil circuit wiring, has affected one bank of cylinders. As I recall it this was a difficult fault to locate. If he does not notice this post, I suggest you send him a PM.

Heat plays game with metal as much as anything else. When the engine is cold it might be tight enough to hold the gear proper, once warm it can be allowed to move on the shaft

Tom

[Trevor]

Originally Posted by yt

Heat plays game with metal as much as anything else. When the engine is cold it might be tight enough to hold the gear proper, once warm it can be allowed to move on the shaft

Tom

To return to the correct position when cold.

Please read the second point I made. Your new identity is rather confusing what gives?