08 Outback XT Engine Rebuild Crank No Start

[tpm55]

On the timing, long story short is that after installing the 10mm oil pump and retiming I felt that the crank sprocket was always off a half a tooth, all other cam marks lined up when the crank sprocket was turned just a bit past its own mark.  No matter how many times I redid it the same result happened.  Once back in the car and attempted start, my first logical thought was that it was the timing being off causing the no run issue.  I took everything off and retimed it and I know at that point the driver's AVCS cam was off one tooth, so I did it one more time counting the teeth and I know its in time now. I would always do 2 full rotations to confirm every time things lined up and that no valves hit each other.  I even ran it with the two side covers off and confirmed things still lined up after running for a bit.  I think I can confidently say that timing should not be an issue at this time.

If a new LH cam sensor does not fix the erratic idle, misfire codes, cam sensor code and then the eventual no start/hard start once hot, I will probably look into other solutions including the possibly the gears may not have been put on correctly.  As you said I feel pretty confident that this is not the issue as it started great cold and ran strong with a good steady idle until it started to warm and that is when trouble set in.  Hopefully its a simple fix but if not I am open to any ideas.  Thanks!

[Infosecdad]

Running fine cold, but freaking out when warm usually points to a sensor.

The ECU will run open loop largely ignoring most of the sensors until the coolant reaches a certain temp, then will switch to closed loop and pay attention to the sensors.

If one is flaking out, that would help explain the behavior you are seeing.

Edited March 31 by Infosecdad
Had switched open/closed loop

[rhino6303]

5 hours ago, Infosecdad said:

Running fine cold, but freaking out when warm usually points to a sensor.

The ECU will run closed loop largely ignoring most of the sensors until the coolant reaches a certain temp, then will switch to open loop and pay attention to the sensors.

If one is flaking out, that would help explain the behavior you are seeing.

This is partially correct/incorrect. Open loop (uses maps and minimal sensors for fueling) is used at cold start and under any "hard" acceleration (several factors met in ecu). Closed loop is alway on once engine is warm (uses oxygen sensors, etc for fueling). This quote is from a thread on the outback forums to be a little more specific:

Fueling on these cars starts with the ECM knowing where TDC is. Then it relies on the cam position to manage injector timing. The injector pulse is determined by TDC, Cam position and the AF sensor feedback at any rpm. The cam sensor is affective from start up.

Higher RPM utilizes the AVCS system to help the car breath better and in conjunction the spark and fuel injector timing is altered based on feedback from several sensors listed below.

CKP
CMP
MAF
IAT
MAP
ECT
AF Sensor(s)
Rear O2 Sensor(s)
Knock Sensor(s)

 

[tpm55]

So I had an hour today so I ran over and switched out the cam sensor on the driver's side (Left Hand).  For anyone's benefit if they ever need to remove it, I had to loosen the entire intake manifold with the TGVs as the sensor can't clear the back of the TGV where the injector protector mounts, I pulled the entire manifold assembly up maybe a half inch and was able to slide the sensor out and same thing to put the new one in.  I did read somewhere people had used a dremel to take off the edge of the mounting tab, I could see this working.

Car started right up and seemed to idle fine.  I warmed it right up and the radiator fans kicked on.  Being winter still in Maine, idling it doesn't seem to get it hot enough to open the thermostat so ill have to wait for a drive for that.  The idle once warm still doesn't seem super stable, still seems a hair rough.  Revving it and letting it get back to idle speed causes the idle to drop low to the point I think it might stall and then speeds up a bit, but still seems a bit rough.  No check engine lights which is good tho, and no codes.  Tomorrow I am going to drop the oil and filter and put in motul break in and a new filter and then hopefully take it on its maiden voyage on the new rebuild, see what happens then, lots of engine braking and stopping and going.  I am hoping the idle will even out over time, but Ill at least data log and see whats going on and maybe fine tune from there checking for possible vacuum leaks or more bad sensors.  I do need to replace the electrical connectors on the coolant temp sensor and the alternator as they are both broken, maybe that is causing a mildly rough idle?  I am doubtful but you never know, from all the reading I have done on these different forums, these cars/engines can be a bit fickle at times.  But its running and revs fine so maybe it just needs to be driven.

[birkhoff]

Why would the rad fans come on when the engine/rad is still cold?  If the T'stat isn't open yet, the rad should be cold/ 

Is it possible that you are not getting a correct coolant temperature to the ECM?  Maybe it thinks the engine is really hot when in fact it is cold.  Or the other way around.  There must be a few parameters in timing and fuel that are modified by the ECM based on engine temp. 

I suppose you could log that and see what the ECM sees for engine temp in the first few minutes of running.  

 

[tpm55]

I had the car idling for about 10-15 minutes so it should have been basically up to temp, or as much as I could get it up to temp with it idling in 30 degree weather. Tomorrow I’ll have to go for a drive and data log, but it’s also possible the electrical connector for the coolant sensor is spoty as it is pretty badly broken. I have a new one to replace it so hopefully things will be okay. The temp gauge read about 1/3 of the way up, I didn’t have my accessport with me to actually see exact values. I believe he t’stat normally opens around 205? The fans were def on but the bottom coolant hose was cold still. 
 

[Infosecdad]

I think the thermostat opens at 180 or 190, the fans should kick on at 205 unless the A/C is on. (If I remember right)

A bad signal from a coolant temp sensor will cause all sorts of issues.

[xt2005bonbon]

If you just reset the ecu, then it is normal for the idle to be a bit rough when you apply some throttle and then let it go back to idle. The ecu is learning. But it does not take very long to learn especially if it idled for a while. At least, my cars behave like that.

[kzr750r1]

Needs that coolant reference.

Should look at Throttle Body calibration. Pretty much letting the ECU get itself settled.

Sounds like your chipping away at it.

[birkhoff]

If you don't fix this via electrical gremlins, another cause for rough idle at temp is valve adjustments out of spec.  That would be kind of ironic given where you started this project but did you happen to check the valve clearances after mounting the heads and cams?  It is not unheard of for machine shops to get this wrong and it is a quick check on their work before you pack things up.  I have a car that suffered from this.  Not a fun prospect to do this with the engine in the car. 

[tpm55]

I did check before putting everything fully back together, the machine shop I used even had their values written down that I could verify with.

Sorry for the slow progress and no updates.  Busy between school, work, and wedding planning.  Should have some time this weekend to tackle the oil leak from the banjo, drain the trans fluid (well whats left, I had to reboot both front axles so some fluid came out and I figured I'd switch it out with motul while I am at it).  Also replacing the trans mount with a group-n 5 speed one.  Then an oil change to motul break in and see what happens on the first drive around town, get some data logging in and go from there.

My assumption is that Ill end up replacing most of the electrical parts as I believe most are original and after 15+ years of heat and abuse they are on their way out, seeing as one cam sensor was already bad.  Either that or I have a small vacuum leak somewhere, I believe the only 2 vacuum lines I haven't replaced are the BPV to manifold and the brake booster to manifold.  Maybe the data logging will reveal something as well. But the idling problem when warm points more to something electrical to me, but we shall see in due time.

[tpm55]

So I was able to go for a first drive this morning, did about 30 miles, lots of slow pulls from 2k-4k and then slowly let the engine slow itself down, also a lot of coasting down hills to really get those rings seated/grind into the crosshatching.  I know a lot more is still to go but I would say it was a success, no issues of note, low idle seemed totally fine, clutch felt good, I seemed to have fixed my oil leak.  I also reworked the IAG turbo/AVCS feed line kit that I bought.  The way it was set up it was next to impossible to disassemble, I ended up buying a short 9" section with a 90 that I placed at the banjo running it to the T-fitting that came with the kit which splits to the turbo and AVCS respectively.  The other issue with their kit I found, and maybe my head was just weird, but it never seemed to clear the head so I could properly torque the banjo down, which is why they give you a thicker crush washer to begin with.  I ended up reversing my 90 so it runs down and then turns directly to the fender where it tees out.  I don't see how this could be a problem and it is super easy to get to now, out of the way of the turbo coolant line too.  The only thing I noticed is that my oil pressure is generally always around 80-90 while cruising even at low RPMs.  Idle its around 35-40 which from reading seemed okay (this is fully warm obviously), but any RPMs at all and it runs higher than what I have read, most say 10 psi for every 1000 rpms.  It is 10w40 Motul break in oil in the car now, so it is thicker than what it calls for but that is what is labeled for use for break in on most sites, I doubt the little extra AN line would cause the oil pressure to be that much higher, especially since the banjos control oil flow to begin with, at least the turbo one does.  Should I be concerned and look into that more? Or it should improve over time with lower weight oil eventually?  My only concern would be the oil bypass always being open.  I attached a somewhat crappy photo of my current oiling setup.  I have seen similar ones posted on here and people report no issues, but maybe I should replace the other longer lines with shorter ones to reduce resistance a bit?

 

I am also going to examine the datalog I took from the drive and see if everything appears to be working okay.

 

 

[xt2005bonbon]

Not answering your question, but what was the problem in the end?

[tpm55]

With the idling? Not really sure.  I didn't do anything in an attempt to directly fix it.  I did replace the broken alternator connector and broken coolant sensor connector, but other than that I just fixed the oil leak as described above and replaced the trans mount and trans fluid and took a long drive.  Idle remained stable. Ill keep updating as I go along and any issues I may have, but so far so good.  My assumption is that over time ill have to replace coils and other sensors like the crank and O2, not sure how new/old any of them are other than obviously the crank.  Looking at the datalog everything seems okay?  I am far from an expert and will be doing a lot of reading on datalogs and proper values.

[xt2005bonbon]

I'd check the following:

-long term fuel trims (should be within +/-5%)

-making sure both OCV angles are in sync and the same, whenever the angle is non zero. Usually happens under load.

-keep an eye on misfire count per cylinder

-knock obviously

 

Both of my cars are still rocking original crank, 02, maf, etc... sensors . I did change one coil pack on each car, but that's it I think. Both 180K+.

Edited Friday at 03:06 PM by xt2005bonbon

[birkhoff]

Quote

3 hours ago, tpm55 said:

With the idling? Not really sure.  I didn't do anything in an attempt to directly fix it.  I did replace the broken alternator connector and broken coolant sensor connector, but other than that I just fixed the oil leak as described above and replaced the trans mount and trans fluid and took a long drive.  Idle remained stable. Ill keep updating as I go along and any issues I may have, but so far so good.  My assumption is that over time ill have to replace coils and other sensors like the crank and O2, not sure how new/old any of them are other than obviously the crank.  Looking at the datalog everything seems okay?  I am far from an expert and will be doing a lot of reading on datalogs and proper values.

 

.... and broken coolant sensor connector . . .  my guess is that was a big problem, given the behaviour of the fans you reported and if the ECU thinks the engine is full hot, when it is not, that will mess up all sorts of things.  Plus probably intermittent. 

I wouldn't worry about the oil pressure you are reporting. In my experience it is highly non-linear and should pop up to max with a modest amount of throttle.  There is an active relief valve in there. 

[xt2005bonbon]

That's a good point. I know that past a certain coolant temperature, the ECU adjusts a bunch of things such as AFR, timing and probably a bunch of other things.

Edited Friday at 04:56 PM by xt2005bonbon

[kzr750r1]

Just take it easy on it for the first 500 miles. Keep out of da boost. Stay on top of the early oil changes.

Found coolant sensors very important even on an old 89 CRX. It was running very rich for a long time. After changing was a different animal.

Then a Prius blasted me in the rear on the freeway. Still kinda miss that little unit. 30MPG all day long no matter how hard you flogged it. Acura trans, CV and Hubs helped keep it solid till the end.

 

[xt2005bonbon]

yeah, when the coolant temp goes above a certain threshold, the ECU commands a richer mixture, probably to help cool down the combustion chamber.

[MrEvanchi]

31 minutes ago, xt2005bonbon said:

yeah, when the coolant temp goes above a certain threshold, the ECU commands a richer mixture, probably to help cool down the combustion chamber.

I haven't come across any AFR compensations in my 07 LGT's stock ROM, but it does at least pull timing with extreme coolant and IAT temps.
-2.11* @ 212F, -3.87* @ 230F Coolant

And -2.11* @104F-158F,  -5.98* @176F+  IAT

Edited Friday at 07:18 PM by MrEvanchi
Rephrase

[xt2005bonbon]

I have to check mine. Maybe I am wrong. But I do recall watching my real time AFR values while coolant temps were above 219F (with IAT>110F) and she was running rich.